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1: High Efficiency Speaker Asylum, RE: JBL E145 vs K145 voice coil heights (0.00)
Posted by Tom Dawson on 2013-02-05, 12:00:41 (204.27.169.105)
Hi, Robert - This is where the difference might be. Even if you call it 7/16", that's a 1/8" difference which could significantly compromise linear Xmax in the outgoing direction if the E145 recone h .......
2: High Efficiency Speaker Asylum, RE: JBL E145 vs K145 voice coil heights (0.00)
Posted by Tom Dawson on 2013-02-03, 09:42:51 (50.9.44.93)
Hi, Robert - Thanks for the information. Can you determine how far the spider mounting on the frame sits in front of the top of the top-plate? From your 13/16" measurement, it would suggest a distanc .......
3: High Efficiency Speaker Asylum, RE: World's biggest bookshelf speakers: The Iron Lawbreaker: 100db/w/m down to 50hz in 100liters (0.00)
Posted by Tom Dawson on 2013-02-02, 12:41:01 (50.9.44.93)
Hi, Freddy - The charcoal will last indefinitely as long as its environment is low humidity - say less than 20-30%. Otherwise, it tends to take up water vapor which blocks micropores that would other .......
4: High Efficiency Speaker Asylum, RE: JBL E145 vs K145 voice coil heights (0.00)
Posted by Tom Dawson on 2013-02-02, 10:54:09 (50.9.44.93)
Hi - Sorry if I forgot to mention that the magnet structures are quite different between the two - the E145 is a ceramic type and the K145 is alnico V, and, as the table shows, the two speakers vary .......
5: High Efficiency Speaker Asylum, World's biggest bookshelf speakers: The Iron Lawbreaker: 100db/w/m down to 50hz in 100liters (0.00)
Posted by Tom Dawson on 2013-02-02, 09:55:36 (50.9.44.93)
I use activated charcoal compliance enhancement (in sealed bags) and have found a way in the xover to convert the upper BR impedance peak into added sensitivity between 50-90hz. Side benefit is a flat .......
6: High Efficiency Speaker Asylum, JBL E145 vs K145 voice coil heights (0.00)
Posted by Tom Dawson on 2013-02-02, 09:19:41 (50.9.44.93)
Hi - How's it going? I've seen on more than one discussion group (without verification) that the JBL E145 recone kit will not align properly in a K145 basket because the voice coil winding is supposed .......
7: OTL Asylum, Re: Theory behind OTL (0.00)
Posted by Tom Dawson on 2007-03-06, 11:00:42 (68.165.202.37)
I've been running a fully DC coupled OTL of an original topology for nearly 20 years now, and would say it is an eminently practical design:) .......
8: General Asylum, Good-bye (0.00)
Posted by Tom Dawson on 2006-08-13, 22:40:02 (4.159.237.66)
I will not be posting much, if at all, in AA for a considerable length of time. This is due both to the exigencies of my employment and a sudden insistence by AA moderators that alternate monikers (to .......
9: Propeller Head Plaza, Re: Why not go them one better and get rid of all your knobs. What do you need them for anyway? (0.00)
Posted by Tom Dawson on 2006-08-01, 16:54:15 (4.158.93.139)
Touche. I had to laugh at this riposte. .......
10: High Efficiency Speaker Asylum, Re: 2204 (0.00)
Posted by Tom Dawson on 2006-07-30, 23:40:04 (4.159.232.55)
djk - thanks for your input. I read that the 2202/2203/2204/K/E120, etc. baskets have a 0.280" top plate. The 2202 vc assembly being underhung would probably be a good thing, IMO. Do you happen to kno .......
11: Propeller Head Plaza, Re: Lossless is lossless... (0.00)
Posted by Tom Dawson on 2006-07-30, 10:45:53 (4.159.239.240)
Even merely requantizing Redbook to a similar ultimate resolution digital format will result in a very perceptible loss in SQ. When adding the degradations due to the time averaging and discarded spec .......
12: High Efficiency Speaker Asylum, JBL 2202B rezapping, reconing questions (0.00)
Posted by Tom Dawson on 2006-07-30, 10:37:26 (4.159.239.240)
I was wondering if anybody could recommend somebody in the midwest who could remagnetize 2202 alnico baskets. Also I thought I would perhaps take a shot at reconing them myself if I could get a hold o .......
13: General Asylum, Re: How Much Current Can You Wusses Take...Ha! (0.00)
Posted by Tom Dawson on 2006-07-30, 09:13:51 (4.159.239.240)
Speaking of wusses, as an EE undergraduate at the U of I, in the engineering dorm, I once charged a ~10,000 uF 40VDC electrolytic to about 35VDC and dared other EE undergrads to touch their fingers ac .......
14: General Asylum, So? 90% of Germans supported Hitler during WWII nt (0.00)
Posted by Tom Dawson on 2006-07-26, 10:40:59 (64.66.93.194)
. .......
15: Propeller Head Plaza, If one reserves the right to continually change the rules, it's no surprise that he can ignore any factual argument. (0.00)
Posted by Tom Dawson on 2006-07-23, 19:14:39 (4.158.126.84)
That's what you pro-IC people are doing, IMO. Furthermore, pro-'Intelligent Chip' people clearly have no real interest in backing up their assertions. That in itself is enough to discredit their claim .......
16: Propeller Head Plaza, Perhaps it was the Armor All he treated it with with its well-known Quantum Dynamic Suppression Effect. nt (0.00)
Posted by Tom Dawson on 2006-07-23, 18:26:04 (4.158.126.84)
:) .......
17: Propeller Head Plaza, that the 'Intelligent Chip' is about as real as the Fiji Mermaid. (0.00)
Posted by Tom Dawson on 2006-07-23, 18:17:40 (4.158.126.84)
From the Wikipedia: A common feature of sideshows, a Fiji mermaid (also Feejee mermaid) is a mummified body of something, supposedly a creature that was half mammal and half fish (like a grotesque ver .......
18: Propeller Head Plaza, ....to substantiate the facts I have been illustrating about the audible superiority of tubes over transistors. (0.00)
Posted by Tom Dawson on 2006-07-20, 19:04:20 (4.158.93.240)
I will repeat myself, more briefly this time. Keep in mind, first of all, that the typical vacuum tube is a more linear device than the typical transistor according to conventional continuous waveform .......
19: General Asylum, Re: Truly the ultimate subwoofer.... (0.00)
Posted by Tom Dawson on 2006-07-19, 18:32:12 (4.131.15.183)
27" passive radiator? Just guessing. IAC, for the last few years, I've had 16 12" woofers each with Xmax of 16mm waiting to be built into two end-table style HT subwoofers. It seems likely that adding .......
20: General Asylum, Re: Eminent Technology makes the ultimate subwoofer. (0.00)
Posted by Tom Dawson on 2006-07-19, 18:19:52 (4.131.15.183)
I prototyped a DC responding subwoofer about 15 years ago that operates on a somewhat different principle. I suppose it's too bad I don't have much of a drive to make a profit from my ideas. ::: TOPIC .......
21: Propeller Head Plaza, Re: Different kinds of problems... (0.00)
Posted by Tom Dawson on 2006-07-18, 19:55:13 (4.159.233.68)
As someone else has mentioned, I think, heat sink fins can ring quite a bit causing microphonic effects in power semiconductors. Another area where I think most power transistors tend to have a weakne .......
22: General Asylum, 85% vinyl, 10% SACD/DVDA, 4% CD, 1% MP3 (0.00)
Posted by Tom Dawson on 2006-07-18, 19:30:41 (4.159.233.68)
I pretty much listen to a vinyl version of a recording given an option. .......
23: General Asylum, Re: What are the definitions of macrodynamics & microdynamics? (0.00)
Posted by Tom Dawson on 2006-07-15, 19:51:44 (4.158.126.92)
I mostly agree with Todd's definition . My basement blaster system from DVDA or SACD (with speakers at 101db/w/m from near 20hz to 20khz backed by an effective 700WRMS a channel class D) excels at mac .......
24: General Asylum, Re: Why bother with iPods... (0.00)
Posted by Tom Dawson on 2006-07-15, 19:30:15 (4.158.126.92)
While I don't bother with IPods today, I'm not about to condemn them because they're continually improving in storage capability and are not restricted to a particular digital audio standard. Since yo .......
25: General Asylum, I have bought CDs recently, and while they are better and some even sound 'ok'.... (0.00)
Posted by Tom Dawson on 2006-07-15, 19:03:55 (4.158.126.92)
I'm into audio to get satisfaction from my recordings, not to cheer on an obviously deficient medium such as Redbook and those associated with producing recordings in that medium, particularly when af .......
26: General Asylum, Here's all the data one could reasonably ask for. However, don't expect a tutorial unless you're willing to pay for it. (0.00)
Posted by Tom Dawson on 2006-07-15, 08:44:44 (4.159.238.143)
First off all silicon semiconductor junction capacitances do indeed have the characteristics of a K=12 dielectric. There's no getting around that. I'm not talking about silicon dioxide which is an ins .......
27: General Asylum, Re: -And that low-K capacitor thing?, OR, why aren't Z5U capacitors good enuf for audio - same deal. (0.00)
Posted by Tom Dawson on 2006-07-14, 01:50:40 (4.159.232.231)
You must first become familiar with the concept of dielectric absorption to understand what I'm talking about and try to get a little beyond the straitjacket of the 1930's vintage standard of steady s .......
28: General Asylum, Re: -And that low-K capacitor thing?, OR, why aren't Z5U capacitors good enuf for audio - same deal. (0.00)
Posted by Tom Dawson on 2006-07-13, 23:02:03 (4.131.12.180)
Dolts like Aczel probably don't even have the technical background to appreciate the fact that tube interelectrode capacitances, because of their ideal dielectric nature, free tubes of a whole myriad .......
29: General Asylum, Re: I could easily discredit #7 & #9... (0.00)
Posted by Tom Dawson on 2006-07-13, 21:48:03 (4.131.12.180)
Peter Aczel is a maybe a little stupid, as well as overly arrogant. Instead of mindlessly asserting that 'biwiring is pure voodoo', he should at least display the mental acuity to admit that it can re .......
30: General Asylum, Re: My first CD player sounded fine. (0.00)
Posted by Tom Dawson on 2006-07-13, 21:36:00 (4.131.12.180)
All the early generation Redbook stuff I heard ranged from irritating to execrable. .......
31: General Asylum, Re: My first CD player sounded fine. (0.00)
Posted by Tom Dawson on 2006-07-13, 21:01:40 (4.131.12.180)
Let me guess. You probably feel that most MP3 sounds 'fine', also. .......
32: General Asylum, Re: "perfect sound forever" is a marketing term (0.00)
Posted by Tom Dawson on 2006-07-13, 20:45:25 (4.131.12.180)
And not just 'non-technical people', either. Popular Science just recently ran a featurette extolling XM and Internet Radio's 'CD-Quality' sound and 'freedom from AM and FM's hiss and static'. Be scar .......
33: General Asylum, Re: How about "Pure Perfect Sound Forever"? (0.00)
Posted by Tom Dawson on 2006-07-13, 14:33:01 (68.165.202.37)
I still haven't listened to any CDs that let me clearly hear (among other things) characteristics of the upstream electronics. LPs typically can do that, even with mediocre master recordings. ::: TOP .......
34: Tube DIY Asylum, Re: Help with math... (0.00)
Posted by Tom Dawson on 2006-07-13, 14:02:40 (68.165.202.37)
I got z=(ln(I/X))/ln(y). .......
35: High Efficiency Speaker Asylum, Re: keep the 'powder' dry (0.00)
Posted by Tom Dawson on 2006-07-12, 18:49:28 (4.131.12.56)
Hi - You're correct that I'm looking at a BR implementation. I'm thinking that having the GAC (along with a bag of some desiccant) in a heavy duty sealtight plastic ziplock bag (not packed tight) mig .......
36: High Efficiency Speaker Asylum, Re: Watch your impedance. (0.00)
Posted by Tom Dawson on 2006-07-12, 18:11:32 (4.131.12.56)
Hi - My goal is to keep the impedance minimum to no less than 10 ohms. I think this is probably compatible with the goals I set for myself, given that the bass drivers are nominal 16 ohm units. 2 db o .......
37: High Efficiency Speaker Asylum, Mini Iron Law Breaker Project taking shape (0.00)
Posted by Tom Dawson on 2006-07-09, 23:14:50 (4.158.93.107)
The goal is to create a 2 way 2cu ft (internal volume) speaker that is good to 100db/w/m and 40 hz. The bass driver I have decided to use is a JBL 2202, which will be remagged with a fresh recone as a .......
38: General Asylum, The BEST CD quality I've ever heard is little better than tolerable. (0.00)
Posted by Tom Dawson on 2006-07-09, 22:36:04 (4.158.51.41)
If it's not an obvious lack of low level detail and consistent spatial imaging, it'll be grotesque alterations in timbre, homogenization of microdynamics, and/or an astringent or sandpapery sonic text .......
39: General Asylum, You're certainly not ashamed of parading your ignorance about LP's ultrasonic capabilities, are you? (0.00)
Posted by Tom Dawson on 2006-07-09, 21:53:10 (4.158.51.41)
Maybe you'd better get off your parent's computer and listen to your I tunes instead. Let people who know what they're talking about discuss the relative SQ of various audio formats without being hara .......
40: General Asylum, Good at covering up & masking Redbook artifacts, at best.... nt (0.00)
Posted by Tom Dawson on 2006-07-09, 21:37:53 (4.158.51.41)
:) .......
41: General Asylum, Brass et al over 20khz w/middle ear IM, Must never have heard of CD4 LP's that go out to 50khz, etc. (0.00)
Posted by Tom Dawson on 2006-07-09, 21:31:14 (4.158.51.41)
Frankly, 'minimumphase' - you sound to me just like you imbibed nothing much more than the Redbook 'perfect sound forever' propaganda and rationalizations of the early '80's and then turned your mind .......
42: General Asylum, 16 bits - 5 bits for over 3% quantization dist. - 1 bit for bipolar signal -4bits for headroom = 6 bits DR (0.00)
Posted by Tom Dawson on 2006-07-09, 21:25:49 (4.158.51.41)
That's less than 40 db effective dynamic range for Redbook on music, and I haven't even mentioned requantization losses, near audio band Gibbs Phenomenon, aliasing artifacts, RF noise injection into .......
43: General Asylum, Vinyl has considerably better low level resolution than Redbook. (0.00)
Posted by Tom Dawson on 2006-07-09, 11:31:21 (4.159.239.208)
The rising low level quantization distortion of 16 bit linear PCM alone attests to that, giving CD a dynamic range ( 3% signal distortion) in the 60 db range. .......
44: OTL Asylum, Re: 6AS7 on low heater voltages (0.00)
Posted by Tom Dawson on 2006-07-07, 01:40:57 (4.159.229.207)
If the tap has a sufficient current rating, you can convert to DC with a schottky bridge rectifier & 'lytic cap & get 6VDC or better from the 5V winding. .......
45: Tube DIY Asylum, Re: Polystyrene caps - are they really that good !!! (0.00)
Posted by Tom Dawson on 2006-07-07, 00:51:11 (4.159.229.207)
I believe polypropylene (K=~2.1) and Teflon (K=~2.0) are both better in this regard than polystyrene (K=~2.6). To me, they sound better, also. .......
46: Propeller Head Plaza, Re: Priorities differ for individuals (0.00)
Posted by Tom Dawson on 2006-07-04, 20:49:42 (4.131.10.64)
Probably the least intrusive electronic eq I've experienced is one I designed, which I call the 'nearly passive' parametric equalizer that I built. All of the signal except for that which was affected .......
47: General Asylum, Re: My friend thinks he wants a Bose wave radio. Any sleepers out there to consider? (0.00)
Posted by Tom Dawson on 2006-07-02, 12:30:59 (4.159.235.159)
Is your friend really willing to lay out $500 for a clock radio? Unless he's made out of money and has no time to look, he should be able to do much better than that. .......
48: Tube DIY Asylum, Re: of course (0.00)
Posted by Tom Dawson on 2006-06-30, 20:17:56 (63.40.158.6)
Hey, I've used both on aluminum and copper. Lucky for me, I've always been a lefty:) .......
49: General Asylum, Re: I use my sirius tuner every day. (0.00)
Posted by Tom Dawson on 2006-06-30, 19:42:51 (63.40.158.6)
It's the benefit of commercial-free programming .... Well, enjoy it while that lasts. Sooner or later, and not very much later, in all probability, particularly if XM and Sirius with their poor sound .......
50: General Asylum, Re: Practice makes pefect, I hope! (0.00)
Posted by Tom Dawson on 2006-06-27, 19:40:47 (63.40.158.50)
It's entirely likely, IMO, that many multitracked recordings have some tracks out of (relative) phase with other tracks. .......
51: General Asylum, So you admit your Polarity Posturing is a Put-on (0.00)
Posted by Tom Dawson on 2006-06-23, 19:42:13 (63.40.158.142)
Thanks for clearing that up beyond any doubt. Btw, my hypothetical audiophile was not fortunate enough to have a polarity reversal switch anywhere in his system. But I'm glad you know that they exist, .......
52: General Asylum, Re: Trouble & fair use (0.00)
Posted by Tom Dawson on 2006-06-23, 15:02:15 (68.165.202.37)
You posted in another thread: Dear music loving audiophiles, This afternoon after listening to several of my Jazz CDs that were either AAD or ADD mastered I noticed that they were almost always master .......
53: General Asylum, Re: I discovered RPN logic in the waiting room (0.00)
Posted by Tom Dawson on 2006-06-22, 18:20:04 (63.40.158.231)
I rather like RPN when it's necessary to use it. And sometimes I'd like to see the US go metric. But neither's happening anytime soon. .......
54: General Asylum, Re: Audio resolution is the ability to retain as much of the original performance as possible with current equipment. (0.00)
Posted by Tom Dawson on 2006-06-21, 20:15:27 (63.40.158.127)
This mostly agrees with my own estimation, except I'm not familiar with the sound of HDCD. There is also the music-simulating noise of MP3 that languishes at the bottom of these rankings. I might put .......
55: General Asylum, Re: Quite possibly (0.00)
Posted by Tom Dawson on 2006-06-18, 21:58:01 (63.40.154.153)
vinyl has no: -quantization errors -jitter -errors due to converter monotonicity problems -distortion due to overrange values from reconstruction -aliasing artifacts -interchannel sampling timing prob .......
56: Propeller Head Plaza, Re: hearing the big picture? (0.00)
Posted by Tom Dawson on 2006-06-18, 21:41:56 (63.40.154.153)
There are few if any mics that make it to the recording studio having less than 100db S/N ratio. 120db or better is more typical. Lots of what you 'hear' on a CD is in the lowest 48 db, in fact, proba .......
57: General Asylum, Re: Quite possibly (0.00)
Posted by Tom Dawson on 2006-06-18, 21:15:35 (63.40.154.153)
Properly implemented, it will sound more similar to good analog than to 99.5% of the digital in the world today, meaning Redbook and worse. If you are referring strictly to the absence of hiss, or of .......
58: General Asylum, Re: Indeed (0.00)
Posted by Tom Dawson on 2006-06-18, 21:07:57 (63.40.154.153)
I didn't miss anything in your post, and I'm not a mind reader, so I cannot be expected to divine your 'true' opinion. I responded to an inapplicable reference to quantum mechanics and audio. ::: TOPI .......
59: General Asylum, Like Redbook, MP3 or XM? LOL (0.00)
Posted by Tom Dawson on 2006-06-18, 19:11:54 (63.40.154.62)
To use quantum physics to give license to nonrobust digital formats would be laughable except it smacks of hackery. .......
60: General Asylum, Re: Famous last words (0.00)
Posted by Tom Dawson on 2006-06-18, 18:46:51 (63.40.154.62)
An all analog optical medium similar in appearance to CD or DVD is quite possible. Using FM modulation techniques, measured parameters that equal or exceed real world digital with such a medium should .......
61: General Asylum, Re: Tube and Vinyl types, If Tubes and Vinyl were to dry up, would Solid State and Digital then hold your interest? (0.00)
Posted by Tom Dawson on 2006-06-18, 18:42:38 (63.40.154.62)
I'm personally not too concerned about tubes, having or being able to get a lifetime supply of any tubes I'll need, but high bit rate digital audio may hold my interest, but not in preference to vinyl .......
62: Propeller Head Plaza, Re: Hearing under noise floor: a test to hear (0.00)
Posted by Tom Dawson on 2006-06-18, 18:13:32 (63.40.154.62)
This is consistent with what I've heard listening to audio. There is also the factor that with noncorrelated noise played through two channel audio, the noise soundfield (with proper imaging) is distr .......
63: High Efficiency Speaker Asylum, Play only LGWG music - the antidote to fullrange intermodulation distortion (0.00)
Posted by Tom Dawson on 2006-06-15, 17:34:02 (63.40.158.234)
IMO, djk has expressed about the best evaluation of the causes of and workarounds for Doppler distortion. .......
64: High Efficiency Speaker Asylum, Re: LC "boost" - how to minimize racheting with some amplifiers? (0.00)
Posted by Tom Dawson on 2006-06-13, 21:52:38 (63.40.158.41)
With a 12 ILB, you might be able to do a pretty compact system. 5mm would be nice, but it seems most really high efficiency drivers tend to have less, unfortunately. B&C Speakers might have some inter .......
65: High Efficiency Speaker Asylum, Re: LC "boost" - how to minimize racheting with some amplifiers? (0.00)
Posted by Tom Dawson on 2006-06-13, 21:19:51 (63.40.158.41)
I always try to provide some sort of at least external potting for round wire inductors in the finished xover if not in the inductor already. To me, it seemed to improve sonic detail closer to what th .......
66: High Efficiency Speaker Asylum, Re: LC "boost" - how to minimize racheting with some amplifiers? (0.00)
Posted by Tom Dawson on 2006-06-13, 20:39:35 (63.40.158.41)
Hi, Freddy - You can increase the impedance as much as you want at the LC boost center frequency by either going with a higher inductance and smaller capacitance value (for a constant resonance freque .......
67: Propeller Head Plaza, Re: I've seen a lot of reviews of tube amps with a high output impedance. (0.00)
Posted by Tom Dawson on 2006-06-12, 19:47:30 (63.40.154.189)
What is solid state grain? How are you quantifying this distortion? Quantifying this distortion with continuous tone measurements is elusive, just as trying to do the same would be with dielectric ab .......
68: Propeller Head Plaza, Re: Any amps with tubes will have more distortion and will distort the frequency response (0.00)
Posted by Tom Dawson on 2006-06-11, 19:45:51 (63.40.158.245)
Thanks. While I value tube sound, I wanted to avoid the sonic problems related to having an output transformer, and I also wanted the option of having a high damping factor across the audio band. Most .......
69: Propeller Head Plaza, Re: Any amps with tubes will have more distortion and will distort the frequency response (0.00)
Posted by Tom Dawson on 2006-06-09, 20:42:25 (63.40.154.120)
I agree with the majority of this. I should mention that 'graininess' is a subjective term and not meant to imply that all SS amps will overtly display such a quality, or that tube amps cannot do so. .......
70: High Efficiency Speaker Asylum, Re: Solar wireless horn loudspeakers (0.00)
Posted by Tom Dawson on 2006-06-09, 19:49:10 (63.40.154.120)
Pretty nice. Watch that you don't let any wasps start building nests in them or you might get a surprise the next time you fire them up:) .......
71: Propeller Head Plaza, Re: I've seen a lot of reviews of tube amps with a high output impedance. (0.00)
Posted by Tom Dawson on 2006-06-09, 19:23:08 (63.40.154.120)
50 watts a side at clipping, which is about what the DC coupled OTL is good for into 8-16 ohms is not exactly what I'd regard as low powered. More like medium powered, perhaps. Its distortion signatur .......
72: Propeller Head Plaza, " Any amps with tubes..." - sounds like blatant anti-thermionic bias to me.... (0.00)
Posted by Tom Dawson on 2006-06-09, 15:05:58 (68.165.202.37)
As I've specified, my DC coupled OTL all triode amplifier has an output impedance of less than 0.1 ohms. Its bass is significantly tighter and more extended than my 500 W/channel Class D amplifiers. B .......
73: Propeller Head Plaza, Re: A straight answer: DBT's are strong evidence not all components sound different & most manufacturers don't like th (0.00)
Posted by Tom Dawson on 2006-06-09, 13:03:22 (68.165.202.37)
That's funny. My Crown K2, Dynaco Stereo 400, Stereo 70 and DC Coupled all triode OTL (homebrew, output damping factor >100) all sound distinctly different from each other on my basement blaster spEak .......
74: Propeller Head Plaza, Like people want pocket protector wielding coke bottle lensed geeks telling them what audio equipment to buy. (0.00)
Posted by Tom Dawson on 2006-06-07, 19:18:57 (4.159.235.106)
At least get a clue from Bose, meter beaters. .......
75: Propeller Head Plaza, Real profits, real placebo effect, DBT validation - well, 2 out of 3 ain't bad. nt (0.00)
Posted by Tom Dawson on 2006-06-07, 19:01:41 (4.159.235.106)
heh .......
76: Propeller Head Plaza, Re: Technical superiority of SACD (0.00)
Posted by Tom Dawson on 2006-06-07, 18:55:02 (4.159.235.106)
Myself, I'm partial to DVDA, with the exception of often awkward menu navigation if a monitor is not used, since it is much more of an open standard and is not burdened by having considerable out of b .......
77: Propeller Head Plaza, Restriction to a single or time limited set of comparative experience(s) cannot fully exercise human differentiation.. (0.00)
Posted by Tom Dawson on 2006-05-25, 19:37:44 (4.159.228.163)
capability to a complex stimulus such as music. .......
78: Propeller Head Plaza, The wise (e.g., Solomonaic) way to resolve this is for you and Geoffkait to go halfies on funding. (0.00)
Posted by Tom Dawson on 2006-05-25, 18:40:12 (4.159.228.163)
Problem solved. .......
79: High Efficiency Speaker Asylum, Re: How might one optimize LC "boost" network to minimize strain on amp? (0.00)
Posted by Tom Dawson on 2006-05-21, 18:37:22 (4.131.11.76)
Hi, freddy - You can raise the impedance minimum caused by the LC to any point up to having no LC by basically increasing the impedance of the LC components while keeping its resonant frequency fixed .......
80: Propeller Head Plaza, "...there's now a chip that doesn't lose its magic power after X "treatments"." There goes the profit margin. (0.00)
Posted by Tom Dawson on 2006-05-19, 11:10:08 (68.165.202.37)
On the positive side for the IC pushers is that they no longer have to lie about the chip 'losing' power it never had. .......
81: High Efficiency Speaker Asylum, Re: Specsmanship (0.00)
Posted by Tom Dawson on 2006-05-18, 06:41:45 (68.165.202.37)
Hi, djk - Thanks for the info. I'll maybe try one of the alnico JBL bass drivers in a 12" size for my next project. .......
82: Propeller Head Plaza, Re: Sez this Microwave Encyclopedia web site (0.00)
Posted by Tom Dawson on 2006-05-16, 18:22:51 (4.131.10.35)
He may have had a passive switching arrangement - I don't recall for sure after 15 years. Also, there were cascaded rolloffs in the example I cited. The important thing is that he was a happier camper .......
83: High Efficiency Speaker Asylum, Re: You need to know specific drivers. That didn't happen in all cases (0.00)
Posted by Tom Dawson on 2006-05-16, 18:17:35 (4.131.10.35)
Thanks. I'm thinking of, for instance, the 2220 & 2202 A, B which suddenly gained improved Xmax ratings when they were transitioned to the H, J suffixes. Or the entire K series which muscled up on imp .......
84: Propeller Head Plaza, Re: Sez this Microwave Encyclopedia web site (0.00)
Posted by Tom Dawson on 2006-05-16, 14:56:41 (68.165.202.37)
Tre- You're right about it being the capacitance - and I didn't do a very good job of making that clear in my 'catchall' style of posting. The generic cabling ran to about 27-30 pf/foot and the low ca .......
85: Propeller Head Plaza, Re: Ah, thanks. (0.00)
Posted by Tom Dawson on 2006-05-16, 09:37:54 (68.165.202.37)
Your statement is not supported by their results. I don't know why not, since I targeted the range at 20khz and above initially and backed it up with plots showing some cables exhibiting this effect .......
86: Propeller Head Plaza, Re: Ah, thanks. (0.00)
Posted by Tom Dawson on 2006-05-16, 09:04:36 (68.165.202.37)
Here's a link to an article with several measured, not calculated responses showing that skin effect is not negligible with many boutique speaker wires at frequencies as low as 20khz even when they ha .......
87: Propeller Head Plaza, Re: 0.5db at 8MHz! (0.00)
Posted by Tom Dawson on 2006-05-16, 08:33:03 (68.165.202.37)
I recall a comparative listening test on my system between a TARA labs speaker cable and a Kimber speaker cable. The Kimber was unquestionable more extended in the HF, but just a tad tizzy and missing .......
88: Propeller Head Plaza, Re: PropHead Dialog - "wear white sheets" Islamic or KKK? (0.00)
Posted by Tom Dawson on 2006-05-16, 08:22:27 (68.165.202.37)
Inquiring minds want to know. .......
89: High Efficiency Speaker Asylum, Question for djk or others familiar with jbl bass drivers (0.00)
Posted by Tom Dawson on 2006-05-16, 08:03:57 (68.165.202.37)
I can't help but notice that several driver types that JBL carried over from alnico to mud magnets seemed to acquire somewhat improved Xmax specs in the process. Were these real improvements in linear .......
90: Propeller Head Plaza, Re: Ah, thanks. (0.00)
Posted by Tom Dawson on 2006-05-16, 07:48:16 (68.165.202.37)
I cross checked this figure before posting it and it agreed within a few percent with a figure given at a second web site for copper wire skin effect depth at 20khz. Furthermore, the second web site w .......
91: Propeller Head Plaza, The ICs in question were the garden variety types supplied with most mass market audio equipment. (0.00)
Posted by Tom Dawson on 2006-05-16, 07:17:36 (68.165.202.37)
The friend's system was rather complex, occupying nearly two racks full of equipment side by side and a typical switching route in said system might travel through four or so components, but they were .......
92: Propeller Head Plaza, Sez this Microwave Encyclopedia web site (0.00)
Posted by Tom Dawson on 2006-05-16, 07:12:37 (68.165.202.37)
I get a skin depth of 0.018" at 20khz, not far from the radius of a 20awg solid conductor. At the skin depth, the resistivity is e (2.71828) times the DC resisitivity. .......
93: Propeller Head Plaza, A friend of mine once replaced his generic IC cabling with low capacitance coax that I recommended and... (0.00)
Posted by Tom Dawson on 2006-05-14, 20:41:22 (4.159.235.212)
not only was the difference readily audible, but installing this cabling had nearly erased a 4db dropoff at 20khz in his system. Even a couple tenths of an ohm resistance in speaker cabling will ofte .......
94: Propeller Head Plaza, I didn't 'almost' design my DC coupled OTL amp and tube Sonic Hologram, btw. (0.00)
Posted by Tom Dawson on 2006-05-12, 20:18:00 (4.158.93.152)
Haven't felt the need to sell busted up scraps of FR4 material under false pretenses, either. .......
95: High Efficiency Speaker Asylum, Re: Why is recorded music usually compressed? (0.00)
Posted by Tom Dawson on 2006-05-11, 18:55:22 (4.159.236.84)
If what you say is true about LPs, then why is most music more heavily compressed today than when LPs were the primary consumer audio medium? Being able to get a measured 90db s/n ratio out of 40Kb/s .......
96: Propeller Head Plaza, You meant 'aspersions'. Dispersion is what is symptomatic of a person's mental faculties if they buy into the IC mythos (0.00)
Posted by Tom Dawson on 2006-05-10, 18:23:47 (4.158.93.129)
nmt .......
97: Propeller Head Plaza, Re: Addressing your speculations (0.00)
Posted by Tom Dawson on 2006-05-10, 18:14:00 (4.158.93.129)
As a result of listening to my vacuum tube sonic hologram generator, I can speak directly to the sibilance pulling situation since one of the most notable individual differences was the improved perce .......
98: Propeller Head Plaza, Re: Or what, of course. (0.00)
Posted by Tom Dawson on 2006-05-09, 11:23:25 (68.165.202.37)
This might be a case where's there's an exception to any single rule. Closed back or compression drivers don't have a significant backwave & so a baffle wouldn't serve the purpose I gave for them. ::: .......
99: High Efficiency Speaker Asylum, So it sounds louder on the average & gets noticed more in noisy environments. nt (0.00)
Posted by Tom Dawson on 2006-05-09, 11:16:24 (68.165.202.37)
:( .......
100: Propeller Head Plaza, Or what, of course. (0.00)
Posted by Tom Dawson on 2006-05-08, 09:31:50 (68.165.202.37)
Even the flimsiest baffle worthy of the name will separate the front wave from the back wave to some degree, generally speaking. More tenuous materials including your 'butterfly wing' may provide some .......
101: Propeller Head Plaza, Re: YES according to Audio Note. (0.00)
Posted by Tom Dawson on 2006-05-07, 21:49:45 (4.131.12.80)
That AN speaker cabinet is no 'butterfly wing'. However, if it sells there may be a future in inflatable speakers. .......
102: Propeller Head Plaza, Re: Based on the discussion below of what constitutes "high fidelity"... (0.00)
Posted by Tom Dawson on 2006-05-07, 21:30:14 (4.131.12.80)
MP3 data rate? .......
103: High Efficiency Speaker Asylum, Re: OB and MDF (0.00)
Posted by Tom Dawson on 2006-05-03, 18:05:21 (4.159.232.249)
I don't believe MDF is particularly non-resonant - its resonances are higher Q and narrower bandwidth compared to plywood - their character is also affected significantly by its adhesive resin. ::: TO .......
104: Propeller Head Plaza, Re: Based on the discussion below of what constitutes "high fidelity"... (0.00)
Posted by Tom Dawson on 2006-05-03, 16:32:25 (4.159.232.249)
I'll take the Walkman, of course. it is not nearly as efficient at achieving the lowest common denominator of sonic birdcage lining. .......
105: Propeller Head Plaza, "Do microphones exist with very narrow accpetance windows?" Shotgun or parabolic mics. (0.00)
Posted by Tom Dawson on 2006-05-02, 11:05:23 (68.165.202.37)
Wrt cross channel effect with speakers, I currently am listening to an all-vacuum tube circuit (no grimy sounding solid state - yay!) of my own design that specifically cancels most of that - sometime .......
106: High Efficiency Speaker Asylum, Re: ping Tom Dawson - open baffle boost question (0.00)
Posted by Tom Dawson on 2006-05-01, 19:05:45 (4.158.126.98)
Hi, Freddy = Sorry for delay in responding, but I wanted to get order in for the 12 I wanted to use. I'm going to go with the JBL 2202J. Very good efficiency, acceptable Xmax and has a 4" VC for bette .......
107: Propeller Head Plaza, Found an industrial strength Intelligent Chip to patch up that MP3 sound? (0.00)
Posted by Tom Dawson on 2006-05-01, 13:58:00 (68.165.202.37)
Inquiring minds want to know. .......
108: Propeller Head Plaza, Nobody to take the blame for XM Radio's typical 40Kb/s per channel data rate. (0.00)
Posted by Tom Dawson on 2006-05-01, 13:37:34 (68.165.202.37)
Claiming CD SQ still elicits a sufficient Pavlovian response in the mass market to make the sell, apparently. Good presentation, btw. .......
109: General Asylum, How does it feel being the Jonathan Swift of digital audio? nt (0.00)
Posted by Tom Dawson on 2006-04-27, 11:42:22 (68.165.202.37)
Hmmm? .......
110: High Efficiency Speaker Asylum, Re: ping Tom Dawson - open baffle boost question (0.00)
Posted by Tom Dawson on 2006-04-27, 09:03:57 (68.165.202.37)
I'm still looking at doing a 12" woofer ILB project soon. Goal: 100db/w/m and below 40hz useable bass in 2 cu ft volume. .......
111: Tube DIY Asylum, Re: Class D amps (0.00)
Posted by Tom Dawson on 2006-04-27, 08:50:32 (68.165.202.37)
I own Crown K1 & K2 & some tube amps, including my DC Coupled OTL. Class D as we know it today can compete with garden variety solid state but not good tube sound SQ wise, IMO. .......
112: High Efficiency Speaker Asylum, Re: ping Tom Dawson - open baffle boost question (0.00)
Posted by Tom Dawson on 2006-04-26, 11:44:37 (68.165.202.37)
Hi, Freddy - Those values should get you some good 8 ohm potential boost around 35 hz. I've gone 30mH on one of the larger Madisound solenoid cores with 14 gauge wire (replaced original windings) befo .......
113: High Efficiency Speaker Asylum, Re: What's more important, the horn or the driver? (0.00)
Posted by Tom Dawson on 2006-04-21, 20:08:59 (4.159.229.135)
Dear Romy - sounds like poster is trying to figure out how to spend $300 per side for HF unit and not be horrified at results. just so many variables that many opt for "fullrange" driver approach. Be .......
114: High Efficiency Speaker Asylum, Re:15 cheap opamps and 17 crappy electrolytics - now many in recording chain 'fore we have to unravel w. redbook ? (nt) (0.00)
Posted by Tom Dawson on 2006-04-20, 19:20:22 (4.159.234.192)
I have the contrarian view that Redbook is not very good at all compared to competent analog, plus it adds plenty of easy ways to crap the sound up even more if proper care is not taken. Generally, I' .......
115: High Efficiency Speaker Asylum, Are you attempting to deny me my right to listen through '15 cheap opamps and 17 even cheaper electrolytics', sir? (0.00)
Posted by Tom Dawson on 2006-04-20, 08:38:34 (68.165.202.37)
I resent the insinuation:) .......
116: Propeller Head Plaza, How about verifying some sort of IC effect on disc transparency, rather than make the mere assertion? (0.00)
Posted by Tom Dawson on 2006-04-19, 10:11:39 (68.165.202.37)
That's what I'm talking about. .......
117: Propeller Head Plaza, Geoff fails to distinguish between an open mind and an empty head (0.00)
Posted by Tom Dawson on 2006-04-19, 09:23:05 (68.165.202.37)
Having an open mind does not mean dismissing all objective criteria, as one currently must when accepting the claims for the so-called 'Intelligent Chip' without not only any independently verifiable .......
118: Tube DIY Asylum, Re: Silver Solder corrosion and Solder in General (0.00)
Posted by Tom Dawson on 2006-04-17, 22:43:26 (4.158.126.201)
That might have been in reference to the corrosive acid core flux that some silver solders came with rather than the solder itself. I've used 4% silver-tin solder with rosin core flux for years with n .......
119: Propeller Head Plaza, Re: More on Class D amps (0.00)
Posted by Tom Dawson on 2006-04-13, 06:56:00 (68.165.202.37)
I suspect Class D amplification will eventually dominate most low end consumer electronics due to its relative efficiency and size and possibly cost advantages. That doesn't mean that these cheap clas .......
120: Propeller Head Plaza, Re: "Copperweld" rings a bell to me. But.. (0.00)
Posted by Tom Dawson on 2006-04-12, 13:25:08 (68.165.202.37)
I believe Copperweld might have been a trademark name that was eventually used as a generic term for copper clad steel wire. If Caymus could find or make up ICs with the stuff such as I described, I b .......
121: Propeller Head Plaza, That's 'non-sequitur', Sparky. nt (0.00)
Posted by Tom Dawson on 2006-04-12, 12:23:48 (68.165.202.37)
fyi:) .......
122: High Efficiency Speaker Asylum, I'm sure you can find someone during the day of reconing who will 'recoil' at your suggestion. (0.00)
Posted by Tom Dawson on 2006-04-12, 11:00:25 (68.165.202.37)
I believe that is standard practice. .......
123: Propeller Head Plaza, How about some nice multistrand copperweld ICs with well oxidized surfaces? (0.00)
Posted by Tom Dawson on 2006-04-12, 10:56:31 (68.165.202.37)
If you don't hear any difference with them, you're safe. .......
124: Propeller Head Plaza, Naw. But I trust that Dan Banquer's measurement of it was done correctly nt (0.00)
Posted by Tom Dawson on 2006-04-12, 10:52:43 (68.165.202.37)
:) .......
125: Propeller Head Plaza, Hmmmm. 4V p-p switching artifacts @ 100khz through my speaker cables. (0.00)
Posted by Tom Dawson on 2006-04-12, 09:28:46 (68.165.202.37)
Not something you'd want to add without good reason, or if you want uncompromised performance, IMO. .......
126: High Efficiency Speaker Asylum, Re: Tom Dawson - Look at LC notch benefits on a conical mid-horn (0.00)
Posted by Tom Dawson on 2006-04-12, 08:09:00 (68.165.202.37)
Hi, Freddy - Very interesting results, particularly how it completely erased the driver's impedance peak and rather nasty narrowband phase rotation, replacing it with a nearly capacitive impedance cha .......
127: Tube DIY Asylum, Microphonic li'l SOBs (0.00)
Posted by Tom Dawson on 2006-04-06, 19:57:08 (4.159.233.212)
...my Amperex white paint bugle boys, that is. I much prefer the sound of 6Bk7B's anyway, u=43, gm=9300umho. As somebody else mentioned there may be better sounding Russian alternatives than the 6DJ8, .......
128: High Efficiency Speaker Asylum, Re: Graphs of little Karlson with LC boost (0.00)
Posted by Tom Dawson on 2006-04-06, 19:45:01 (4.159.233.212)
Hi, Freddy - Perhaps tacking on another 5mH and reducing C accordingly, or by a bit less might lead to more optimal results. B&C, particularly, & perhaps Eminence make a couple 15" drivers in the 100d .......
129: High Efficiency Speaker Asylum, Re: I'll sell you my B&Cs (0.00)
Posted by Tom Dawson on 2006-04-06, 19:14:19 (4.159.233.212)
B&C just seems to be better engineered than Selenium. .......
130: High Efficiency Speaker Asylum, Re: Graphs of little Karlson with LC boost (0.00)
Posted by Tom Dawson on 2006-04-06, 18:48:41 (4.159.233.212)
Good set of plots, Freddy. If you could give up the 1db or so of rising reponse around 80 hz (increasing inductor value slightly, etc.), the impedance minimum would go up to 3.5 - 4 ohms. I've found t .......
131: High Efficiency Speaker Asylum, Re: What's TAS? (0.00)
Posted by Tom Dawson on 2006-04-05, 18:45:08 (4.159.238.207)
It's one of the snobbier chinless artsy-fartsy audio boutique rags. Don't worry about it -just turn your Wave Radio up. .......
132: High Efficiency Speaker Asylum, Re: Lowest HD in a waveguide? (0.00)
Posted by Tom Dawson on 2006-04-05, 18:30:02 (4.159.238.207)
I look forward to seeing the published data. IAC, if I ever get around to it, I've decided the mid-high horn I cast (in concrete, my favorite horn material) will be in accordance with the low diffract .......
133: High Efficiency Speaker Asylum, Re: Lowest HD in a waveguide? (0.00)
Posted by Tom Dawson on 2006-04-04, 18:28:34 (4.158.51.168)
More or less I'm ready to buy into Earl Geddes contention that reflective modes are the significant culprit wrt horn SQ. Regardless of phase angle, the 2nd harmonic distortion of horns particularly su .......
134: High Efficiency Speaker Asylum, Re: new speaker "break-in" question (0.00)
Posted by Tom Dawson on 2006-04-04, 18:02:14 (4.158.51.168)
Pressed waste material has a much higher percentage of resin adhesive of plasticy acoustical properties than plywood does. Both offer relative dimensional stability. Baltic birch plywood is both signi .......
135: High Efficiency Speaker Asylum, Re: Do you mean Low Pass? nope - high pass for midrange (0.00)
Posted by Tom Dawson on 2006-04-03, 20:48:57 (4.158.51.142)
Actually, related to your observation, I was suggesting that a fairly broad LC notch centered at around 150 hz, as a partial result of giving a much faster initial rolloff below the nominal xover freq .......
136: High Efficiency Speaker Asylum, Re: new speaker "break-in" question (0.00)
Posted by Tom Dawson on 2006-04-03, 20:38:12 (4.158.51.142)
Well, for ultimate SQ, mud magnets are a little bit the other end of the cat from the meow, if you take my meaning. Not that I don't have them in the basement blasters & for the ILB woof. .......
137: High Efficiency Speaker Asylum, Re: new speaker "break-in" question (0.00)
Posted by Tom Dawson on 2006-04-03, 19:07:06 (4.158.51.109)
I'm not an expert on the Altec 604 (although I once owned a 416B), but this speaker may benefit from a serious break in. At least my 2226J's did, with their Fs dropping almost 10 hz after I ran them i .......
138: High Efficiency Speaker Asylum, Re: how ya folks dealin' with speaker Z interaction w. passive xover? (0.00)
Posted by Tom Dawson on 2006-04-03, 12:33:17 (4.159.237.146)
The L and C should be seriesed to give the notch. The LC network placement is correct. Let me know what you think if you try it. I should mention briefly that there is another resonant interaction of .......
139: High Efficiency Speaker Asylum, Re: how ya folks dealin' with speaker Z interaction w. passive xover? (0.00)
Posted by Tom Dawson on 2006-04-03, 11:50:31 (4.159.237.146)
Normally, I'd probably start with a notch in the 150-175hz range, near that 200hz impedance peak (would stuffing help control impedance peak also?) assuming the nominal 400 hz xover, but the response .......
140: Propeller Head Plaza, They sure do. (0.00)
Posted by Tom Dawson on 2006-04-03, 00:08:41 (4.159.233.240)
Just a few experiences: I haven't decided whether I prefer silver or copper, but they certainly do sound different to me. Their milspec bastard child, silver plated copper (to apply TFE insulation) is .......
141: High Efficiency Speaker Asylum, Re: how ya folks dealin' with speaker Z interaction w. passive xover? (0.00)
Posted by Tom Dawson on 2006-04-02, 22:42:55 (4.159.233.240)
Quasi first order w/ out of band notch does the trick for me. No problems impedance wise, either. .......
142: High Efficiency Speaker Asylum, Re: Hey Tom Dawson - here's non-optimized LC "boost" on K12 size (0.00)
Posted by Tom Dawson on 2006-04-01, 18:23:20 (4.158.126.56)
re: low xover 1st order - do you have notch filter there too to limit out of band modulation? I don't like to see cones move at all Definitely. On the ILB's, I once seriesed up jumpers with the 288G .......
143: High Efficiency Speaker Asylum, Re: Hey Tom Dawson - here's non-optimized LC "boost" on K12 size (0.00)
Posted by Tom Dawson on 2006-04-01, 17:57:34 (4.158.126.56)
You pr obably know me by now with my quasi first order xovers - I like to go straight to a horn mid-high as low as possible. If I'd found an 18" woofer I really liked a lot, I might have tried mating .......
144: High Efficiency Speaker Asylum, Re: Hey Tom Dawson - here's non-optimized LC "boost" on K12 size (0.00)
Posted by Tom Dawson on 2006-04-01, 17:24:47 (4.158.126.56)
That's pretty interesting. I bet with a little judicious tweaking (& I wonder if a little absorptive material to control response in the front chamber above 500hz wouldn't be a bad thing), some of the .......
145: High Efficiency Speaker Asylum, Re: Hey Tom Dawson - here's non-optimized LC "boost" on K12 size (0.00)
Posted by Tom Dawson on 2006-04-01, 17:01:44 (4.159.239.3)
It's good to hear that about that 'lytic. My rather informal analysis, btw, indicated that at the frequency at which there is the most LC boost, the voltage across the capacitor will exceed that acros .......
146: High Efficiency Speaker Asylum, Re: Hey Tom Dawson - here's non-optimized LC "boost" on K12 size (0.00)
Posted by Tom Dawson on 2006-04-01, 14:21:04 (4.159.239.3)
Looks like that extra LC third octave or so extension is coming in at a useful frequency range. That's some pretty serious efficiency you're getting there, too with the K12. Wonder if there's some K-K .......
147: High Efficiency Speaker Asylum, Re: HE and big power is better yet (0.00)
Posted by Tom Dawson on 2006-03-28, 21:34:26 (4.159.234.66)
agree with Tom for extreme dynamic fun. My Basement Blasters & Iron Lawbreakers are both around 101db/w/m efficiency but the BB is being driven by about 700 effective watts a side compared to the IL .......
148: High Efficiency Speaker Asylum, Re: why are you guys into high eff and not normal dynamic speakers? (0.00)
Posted by Tom Dawson on 2006-03-28, 21:13:58 (4.159.234.66)
...it is done by using an acceleration based driver who’s inherent acoustic phase tends to lag –90 from the input signal. This spreads an impulsive signal out in time and prevents a direct radiator w .......
149: High Efficiency Speaker Asylum, Dynamics are more normal with high eff speakers. (0.00)
Posted by Tom Dawson on 2006-03-28, 14:36:44 (4.158.51.210)
More highs, more lows, less like Bose. Plus you get more out of your first watt. .......
150: High Efficiency Speaker Asylum, Semantic distinctions, etc. (0.00)
Posted by Tom Dawson on 2006-03-28, 13:55:57 (4.158.51.210)
While it's more comprehensive to discuss phase distortion in the context of group delay distortion, to aver one is 'audible' and the other is 'not audible' does not necessarily logically follow since .......
151: High Efficiency Speaker Asylum, Re: LC boost jumpin' haha (0.00)
Posted by Tom Dawson on 2006-03-26, 09:40:12 (4.159.227.85)
Looks impressive, Freddy. Btw, I should mention that, besides my DC Coupled OTL, my Stereo 70 doesn't have any trouble driving the Basement Blasters with its LC boost from its 4 ohm taps. .......
152: High Efficiency Speaker Asylum, Not always (0.00)
Posted by Tom Dawson on 2006-03-24, 19:02:51 (4.158.93.208)
In simple implementations can give saddle shaped responses, and then you have diminishing returns to justify past a certain point, too. .......
153: High Efficiency Speaker Asylum, Re: Samson cracking under low Z load ? (0.00)
Posted by Tom Dawson on 2006-03-24, 18:52:17 (4.158.93.208)
Hi, Freddy - Well, you have two more outputs/channel and almost twice the supply transformer that my OTL has (although toroids tend to overheat before they run out of output capability) and the DC cou .......
154: High Efficiency Speaker Asylum, Re: Samson cracking under low Z load ? (0.00)
Posted by Tom Dawson on 2006-03-24, 17:41:42 (4.158.93.208)
Hi, Freddy - Your Samson amp is rated by the manufacturer for 2 ohm loads and your current impedance minimum is not that low, although a little bit reactive at the min. You can select L and C to provi .......
155: High Efficiency Speaker Asylum, Re: 2226 / level / distortion (0.00)
Posted by Tom Dawson on 2006-03-23, 19:12:54 (4.158.51.33)
The BBs each have 3 2226s in half arrays (time compensated), and even though these JBLs are not the last word in acoustic transparency, the sheer power compression overkill is readily noticeable to me .......
156: High Efficiency Speaker Asylum, Re: drivers 100 – 3000, 95+ dB, without unwanted peaks!? (0.00)
Posted by Tom Dawson on 2006-03-23, 19:06:52 (4.158.51.33)
Even many 6.5" drivers with smaller VCs would probably be breaking up @ 3khz. I wouldn't expect top quality sound in that range, especially if the driver is not very well engineered. .......
157: High Efficiency Speaker Asylum, Re: Measure the distance betwen your eardrums. (0.00)
Posted by Tom Dawson on 2006-03-23, 18:51:55 (4.158.51.33)
I don't know that a hard distinction in audibility should necessarily be drawn between 'phase delay' and 'non minimum phase group delay' as you put it, since both significantly affect the envelope res .......
158: High Efficiency Speaker Asylum, Re: LC boost jumpin' haha (0.00)
Posted by Tom Dawson on 2006-03-23, 18:30:06 (4.158.51.33)
cheap 500uF lytic's hangin' better than the amp! Well, I'll be dawged. I am running pretty low BB Fb - about 26 hz & using 1300uF capacitance. This gives me most boost from 30-40 hz and a little bit .......
159: High Efficiency Speaker Asylum, Re: LC boost jumpin' haha (0.00)
Posted by Tom Dawson on 2006-03-23, 18:06:02 (4.158.51.33)
Hi, Freddy - Looks like you have some serious energy storage happening in the LC! What I did for the BB's is series up two 15mH 600 watt rated for more high output linearity. Does the 'lytic get warm .......
160: High Efficiency Speaker Asylum, Re: hey Tom Dawson - ILB - k12 (0.00)
Posted by Tom Dawson on 2006-03-22, 17:31:18 (4.158.93.99)
I think it's cool to have a mid size speaker that plays with the big boys. That hemp 8" speaker looks like a really mellow performer, judging by its published curves. Maybe a super 2220 type speaker w .......
161: High Efficiency Speaker Asylum, Wave radio sounds 'nice' too. (0.00)
Posted by Tom Dawson on 2006-03-21, 20:41:51 (4.159.224.6)
Nobody is claiming that Bose is incompetent, especially at cleaning out peoples' wallets. .......
162: High Efficiency Speaker Asylum, Re: LCR trap on woofer - what's your success rate? (0.00)
Posted by Tom Dawson on 2006-03-21, 20:29:41 (4.159.224.6)
Hi, Freddy - I pick the LC values on two bases: reducing harmonic distortion due to cone breakup and greatly reducing out of band response of the woofer. If I put the notch right at or just below the .......
163: High Efficiency Speaker Asylum, Re: Have you found cat proof speakers? (0.00)
Posted by Tom Dawson on 2006-03-20, 22:08:54 (4.158.126.130)
You can make a cheap grill cloth frame from 1/4" masonite, paint it black and buy inexpensive black grille cloth material to stretch over it. Attach with velcro strips if needed. I've spread a thin la .......
164: High Efficiency Speaker Asylum, Re: LC boosting of some vented systems - Cost of LF lunch using passive LC (0.00)
Posted by Tom Dawson on 2006-03-20, 21:49:43 (4.158.126.130)
Hi, Freddy - You could probably bring that minimum up to 5 ohms by tweaking L & C (more mH, fewer uF) values if desired - you'd lose about a db or two max boost by doing so. Also, reducing LC passive .......
165: High Efficiency Speaker Asylum, Re: LCR trap on woofer - what's your success rate? (0.00)
Posted by Tom Dawson on 2006-03-20, 21:26:21 (4.158.126.130)
Works well for me, since it can work well well with a simple series choke for a quasi first order LP xover implementation. .......
166: Tweakers' Asylum, Re: DIY Sonic Hologram question (0.00)
Posted by Tom Dawson on 2006-03-19, 19:01:20 (4.131.14.104)
Hi - Yes, I'd be interested in taking a look at the C9 schematic if that is possible. Do you have my email address? Regards, Tom Dawson .......
167: Hi-Rez Highway, From Wikipedia's 'Format Wars' (0.00)
Posted by Tom Dawson on 2006-03-10, 21:08:59 (4.131.8.146)
Hi-fi digital audio discs: DVD-Audio versus SACD. These two formats are likely to coexist due to newer players that handle both formats with equal ease, though neither has caught on with the market a .......
168: High Efficiency Speaker Asylum, Re: not to rock the boat, but... (0.00)
Posted by Tom Dawson on 2006-03-10, 13:33:54 (4.159.234.145)
One can use a time delay relay with a fast dropout for automatic cap bypassing. .......
169: Tweakers' Asylum, DIY Sonic Hologram question (0.00)
Posted by Tom Dawson on 2006-03-09, 21:41:43 (4.159.235.246)
Does anybody happen to know what cross-channel frequency shaping (if any) produces the best sonic hologram effect? I've dusted off an old sonic hologram generator I made (with vacuum tubes, yet) and e .......
170: Propeller Head Plaza, Re: Class D Amps (0.00)
Posted by Tom Dawson on 2006-03-08, 22:20:40 (4.158.126.213)
It's this type of thing that makes me cringe over the notion of broadband signals being transmitted via the AC mains lines. As long as the power is not excessive & particularly if the AC is in condu .......
171: High Efficiency Speaker Asylum, Re: The amazing thing about vented systems (0.00)
Posted by Tom Dawson on 2006-02-15, 00:20:33 (4.158.126.179)
Hi - I was considering the initial envelope amplitude response of the tone bursts shown. The BR took 3/4 of a cycle to reach 70% (approximately -3db) of the final amplitude vs 1/4 of a cycle for the c .......
172: High Efficiency Speaker Asylum, So you became tired of DIYAudio's ****? (0.00)
Posted by Tom Dawson on 2006-02-13, 20:06:00 (4.159.233.217)
Oh, well. Different smokes for different blokes. .......
173: Propeller Head Plaza, Re: 'Unlike software, there are no precise data patterns in music. So I question whether "lossless" can truly be lossles (0.00)
Posted by Tom Dawson on 2006-02-13, 14:19:47 (164.54.52.49)
But then again, even if the files can be restored exactly like the original, when playing lossless files, the conversion on-the-fly is likely to exacerbate jitter and add RFI. This can be expected wi .......
174: High Efficiency Speaker Asylum, Re: if a system can't play 2 instruments - how might it fare with more? (0.00)
Posted by Tom Dawson on 2006-02-13, 08:54:27 (164.54.52.49)
Hi, Freddy - is that 700 a 288 on MCM horn? Actually, the 288-G is doing 550 on a Pyle Pro aluminum 40x90 flat front w/400hz cutoff using a quasi-first order xover. I found that having the out of ban .......
175: High Efficiency Speaker Asylum, Re: if a system can't play 2 instruments - how might it fare with more? (0.00)
Posted by Tom Dawson on 2006-02-13, 08:03:38 (164.54.52.49)
Hi, Freddy - I can say that my BBs are not particularly prone to gargle having a 700hz xover, but I can induce a definite case of it on a few tracks with boosted bass at high playback levels. (I can s .......
176: High Efficiency Speaker Asylum, Re: Tom - a good try (0.00)
Posted by Tom Dawson on 2006-02-12, 19:38:50 (4.159.230.54)
Any minimum phase system with a constant angular phase response over a frequency range will also have zero group delay over that frequency range, since the group delay is the negative differential of .......
177: High Efficiency Speaker Asylum, Re: The amazing thing about vented systems (0.00)
Posted by Tom Dawson on 2006-02-12, 12:40:03 (4.158.93.246)
I've found a link with actual comparative tone burst measurements between closed box, BR & passive radiator (for a 6.5" driver having a nominal BR response to 50 hz.) For a system using a 15" woofer, .......
178: High Efficiency Speaker Asylum, Re: Hitting a loaded cement truck... (0.00)
Posted by Tom Dawson on 2006-02-10, 16:42:21 (164.54.52.49)
For fun, I once calculated how fast a ping pong ball would have to be traveling to stop a freight train moving at 80 mph in a head on collision. It turned out to be well 'over' 99% the speed of light: .......
179: High Efficiency Speaker Asylum, Re: How do YOU match dynamics? (0.00)
Posted by Tom Dawson on 2006-02-10, 16:30:40 (164.54.52.49)
With the Basement Blasters, I matched the 111db/w/m 2445J/40x90CD horn to the 101db/w/m 8 ohm equivalent woofers half array with a tapped choke for maximum coupling (& to suppress response variations .......
180: High Efficiency Speaker Asylum, Re: On the audibility of group delays (0.00)
Posted by Tom Dawson on 2006-02-10, 08:29:07 (164.54.52.49)
To my imperfect understanding, there is some ability to perceive transient envelope/waveshape information as well as steady state information, although it would presumably be harder to demonstrate wit .......
181: High Efficiency Speaker Asylum, Re: Effects of series capacitance w. woofer - what can it do? (0.00)
Posted by Tom Dawson on 2006-02-08, 15:36:56 (164.54.52.49)
I was able to get a very small increase in bass extension with a series C only. It's when I added the shunt L which flattened the upper impedance peak (for BR) that serious options for increasing bass .......
182: High Efficiency Speaker Asylum, Re: DR woofer with horn/waveguide - how to properly add allpass lattice network? (0.00)
Posted by Tom Dawson on 2006-02-08, 14:53:13 (164.54.52.49)
Hi, Freddy - You could do it empirically in stages, where you tweak the all pass/driver combo for the (flat) amplitude & delay characteristic you want, then add the dedicated frequency shaping compon .......
183: High Efficiency Speaker Asylum, Re: DR woofer with horn/waveguide - how to properly add allpass lattice network? (0.00)
Posted by Tom Dawson on 2006-02-08, 09:27:26 (164.54.52.49)
I once did a design with a first order delay network that had this configuration. This network wants to see a constant impedance load with frequency or else the all pass frequency response goes nonfla .......
184: High Efficiency Speaker Asylum, Re: Sure (0.00)
Posted by Tom Dawson on 2006-02-04, 22:17:46 (4.158.126.195)
Which one to get a picture like in your photo and how much? Will it do 1080 vertical line resolution? TIA. Tom Dawson .......
185: High Efficiency Speaker Asylum, Re: can you provide me with some links.. (0.00)
Posted by Tom Dawson on 2006-02-02, 21:07:08 (4.159.235.74)
Hi - I've mostly only discussed them to any extent in this forum. If you search the archives, you can probably find most of what I posted. .......
186: Propeller Head Plaza, I'm still waiting for somebody to measure *any* result from GSIC treatment. (0.00)
Posted by Tom Dawson on 2006-02-02, 15:00:16 (164.54.52.49)
Good thing I'm not holding my breath. .......
187: High Efficiency Speaker Asylum, Re: picking ballpark LC networks for reflex and bandpass -? (0.00)
Posted by Tom Dawson on 2006-02-01, 19:25:58 (4.159.224.200)
Hi, Freddy - I honestly can't say - for me, the dynamic capability losses due to the direct radiator/horn mid time alignment gain could be largely made up with 2 or more woofs, hence the 'Basement Bla .......
188: High Efficiency Speaker Asylum, Re: picking ballpark LC networks for reflex and bandpass -? (0.00)
Posted by Tom Dawson on 2006-02-01, 19:13:39 (4.159.224.200)
Hi, Freddy - My approach has been mostly non SW application aided, and has evolved over time somewhat. Originally, I was trying to support an 80 hz straight tractrix front flare with a BR loading of t .......
189: High Efficiency Speaker Asylum, Re: What's wrong with wall/corner positioning in general? (0.00)
Posted by Tom Dawson on 2006-02-01, 18:51:37 (4.159.224.200)
Symmetrical Corner placement (with maybe a Cornwall in the middle) has its own sonic advantages, and for those with resources to spare, I'll tip my hat to non digitally time aligned multiway all strai .......
190: High Efficiency Speaker Asylum, Re: High efficiency bookshelf recommendations (0.00)
Posted by Tom Dawson on 2006-02-01, 18:26:56 (4.159.224.200)
Well, 100 liters will buy you 100db/w/m and useable response to at least 30 hz if you go the Iron Law Breaker route:) 50 liters should get you the same efficiency and 40 hz. I erased the original po .......
191: Tube DIY Asylum, Re: what triode/pentode ? That's interesting! (0.00)
Posted by Tom Dawson on 2006-01-31, 15:11:25 (164.54.52.49)
Hi, Ray - Yes. It's been a while and I only built a prototype, so I won't be able to recall precisely which one without digging into some old notes. A really interesting feature about this circuit is .......
192: High Efficiency Speaker Asylum, Re: Yes, but . . . (0.00)
Posted by Tom Dawson on 2006-01-31, 14:26:35 (164.54.52.49)
Splayed drivers can give an approximation of controlled directivity at shorter wavelengths:) .......
193: Tube DIY Asylum, Re: Ag or Cu etc (0.00)
Posted by Tom Dawson on 2006-01-31, 14:15:28 (164.54.52.49)
I'll weigh in on Ag vs Cu by saying that I definitely have heard a difference, but haven't conclusively decided which is more accurate or which I prefer, although I lean toward silver. .......
194: Tube DIY Asylum, triode/sharp cutoff pentode CCS (0.00)
Posted by Tom Dawson on 2006-01-31, 14:12:05 (164.54.52.49)
You can make a pretty hi impedance CCS for this type of application using this type of tube with the triode boosting the impedance by driving the pentode screen grid. I was able to build a transformer .......
195: High Efficiency Speaker Asylum, Re: hey T. Dawson - Iron Law Breaker projects -? (0.00)
Posted by Tom Dawson on 2006-01-29, 20:41:47 (4.159.239.52)
Yep, and if you hide that part of your xover, you'll have your friends scratching their heads wondering how you got so much bass out of that combo:) For Qts upper limit, I'd go maybe 0.30 or so, but t .......
196: Propeller Head Plaza, It's already the minimum pro standard; dvda supports, it, etc.... (0.00)
Posted by Tom Dawson on 2006-01-29, 01:06:29 (4.158.126.59)
We're slowly, too slowly, putting the dark days of redbook behind us. .......
197: Propeller Head Plaza, Re: Overkill can be good. (0.00)
Posted by Tom Dawson on 2006-01-29, 00:41:27 (4.158.126.59)
Hey, those 1db dynamic range mixes are about getting 'heard in the 'hood'! .......
198: Propeller Head Plaza, Re: Well, actually, I do know what kind of filter but it's not particularly relevant. (0.00)
Posted by Tom Dawson on 2006-01-25, 15:03:02 (164.54.52.49)
IMO, there's no such thing as getting 44.056Ks/s 'right' for audio unless you don't mind being down several db at 15khz. .......
199: High Efficiency Speaker Asylum, Re: ping Tom Dawson - LC network question (0.00)
Posted by Tom Dawson on 2006-01-25, 10:02:13 (164.54.52.49)
I've heard tell that the Erse are possibly a bit better than the Madisounds, but no direct experience. What I've done if I want to wind a higher value than standard (although you might get by with 15 .......
200: High Efficiency Speaker Asylum, Re: Agreements and disagreements (0.00)
Posted by Tom Dawson on 2006-01-24, 22:57:23 (4.158.93.96)
I don't see that there is necessarily much of a problem with vertically aligned drivers being up to half a wavelength or so apart at xover such as I have done, since under that condition, the lobing n .......
201: Propeller Head Plaza, Re: Um, no. (0.00)
Posted by Tom Dawson on 2006-01-24, 18:17:31 (4.159.231.203)
Let me guess. The electronics used for this subjective evaluation included a Crown IC-150 and DC-150 driving stacked Advents:) .......
202: High Efficiency Speaker Asylum, Re: ping Tom Dawson - LC network question (0.00)
Posted by Tom Dawson on 2006-01-24, 17:46:09 (4.159.231.203)
Hi, Freddy - You might want to experiment, but around 20mH and 800uF should definitely buy you some added LF between 30 & 50 hz. I picked these values to give you a little useful boost near your imped .......
203: High Efficiency Speaker Asylum, Re: Some characteristics differ (0.00)
Posted by Tom Dawson on 2006-01-19, 16:07:45 (164.54.52.49)
Thanks for the concise explanation. And to those who persist in claiming that 'Once you've heard one magnet, you've heard them all', 'Here's mud magnet in your ear.'. .......
204: High Efficiency Speaker Asylum, Re: 18" Eminence Magnum HO LF no peak + horn comp. driver (0.00)
Posted by Tom Dawson on 2006-01-19, 08:00:47 (164.54.52.49)
Hi, Freddy - proper summation is tough and in narrow window (?) I think when woofer is rattlin' up high I agree, and that's where a out of band notch can come in extra handy - it can often make a woo .......
205: High Efficiency Speaker Asylum, Re: dividing the horn/whatever spectrum - what makes for good tradeoffs? (0.00)
Posted by Tom Dawson on 2006-01-18, 22:37:32 (4.158.126.244)
This is largely how I look at it also. With an xover around 500hz and the HF horn very close to the direct radiator bass driver vertically, the vertical lobing response at the xover actually turns int .......
206: High Efficiency Speaker Asylum, Re: Not bandpass LC boost and bass quality discrepancy observation (0.00)
Posted by Tom Dawson on 2006-01-17, 22:00:22 (4.131.12.89)
Hi, Freddy - I was actually looking at a few of their 10 & 12 inchers, thinking of doing a 'mini' basement blaster with 4 10's or 3 12's a side, perhaps with neo magnets for HT front channels. The kil .......
207: High Efficiency Speaker Asylum, Re: Basement Blaster Square waves (0.00)
Posted by Tom Dawson on 2006-01-17, 21:34:23 (4.131.12.89)
Hi - With my basement blasters, I'm running a Crown K2, although I eventually plan to move them to a Crown K1 and use the K2 for HT subwoofer duty. We're talking serious hearing damage potential here .......
208: High Efficiency Speaker Asylum, Not bandpass LC boost and bass quality discrepancy observation (0.00)
Posted by Tom Dawson on 2006-01-17, 20:34:28 (4.131.12.89)
My experience is that passive LC boost can be configured to both buy an additional third octave extension and somewhat improved group delay immediately above that range compared to BR tuning w/o. The .......
209: High Efficiency Speaker Asylum, Re: Basement Blaster Square waves (0.00)
Posted by Tom Dawson on 2006-01-16, 19:58:00 (4.158.93.127)
Hi - The basic topology is a series LC resonant network across the VC after the series inductor or capacitor. Of course, I've gotten a (within limits)similar transfer characteristic with a twin-T notc .......
210: High Efficiency Speaker Asylum, Re: Do you know (0.00)
Posted by Tom Dawson on 2006-01-16, 19:49:07 (4.158.93.127)
Hi - I pretty much prefer air core inductors, most particularly foil types, because of skin effect advantages and better immunity to interwinding vibration. However, the insulator's dielectric propert .......
211: High Efficiency Speaker Asylum, Re: Time delay in a rear-loaded horn? (0.00)
Posted by Tom Dawson on 2006-01-16, 19:28:00 (4.158.93.127)
When I tried to improve a rear-loaded horn design I was working on a few years back, I quickly went to using as much stuffing as I could manage without blocking the horn path in an attempt to smooth o .......
212: High Efficiency Speaker Asylum, Basement Blaster Square waves (0.00)
Posted by Tom Dawson on 2006-01-15, 21:22:32 (4.131.14.38)
Here's a few I posted nearly a year and a half ago of my right Basement Blaster in situ in my basement without any acoustical treatment around it, more or less on the horn axis. There is some hum over .......
213: High Efficiency Speaker Asylum, Boy, you sure put the MIL-C-19978D test in its place! (0.00)
Posted by Tom Dawson on 2006-01-13, 23:35:51 (4.158.126.159)
Guess everybody will have to start pretending that DA doesn't exist any more since you don't believe (know about) it! .......
214: High Efficiency Speaker Asylum, I just knew SE would start out by denigrating the applicability of the milspec test.... (0.00)
Posted by Tom Dawson on 2006-01-13, 23:22:54 (4.158.126.159)
Reread my post (much) more carefully, please. Your narrow interpretation concentrating on the mil test's particular time constants (a clear red herring) show that you don't really (want to) comprehend .......
215: High Efficiency Speaker Asylum, I was just giving SE a little food for thought up front. nt (0.00)
Posted by Tom Dawson on 2006-01-13, 22:50:06 (4.158.126.159)
. .......
216: High Efficiency Speaker Asylum, Re: Curious (0.00)
Posted by Tom Dawson on 2006-01-13, 22:43:40 (4.158.126.159)
I recall seeing a comparative test on the web where the most commonly available types of ferrite, iron and steel core inductors were measured and compared, and disortion differences amounting to almos .......
217: High Efficiency Speaker Asylum, Re: To a certain extent (0.00)
Posted by Tom Dawson on 2006-01-13, 22:01:45 (4.158.126.159)
Now, can you tell me just how a capacitor in service say as a coupling cap in an audio amplifier is ever going to see a situation even remotely resembling what you describe above? You seem to be sug .......
218: High Efficiency Speaker Asylum, Re: To a certain extent (0.00)
Posted by Tom Dawson on 2006-01-13, 18:06:17 (4.158.93.111)
The MIL-C-19978D test, commonly referenced among capacitor manufacturers, specifies a five second charge time, a five second discharge time (into a dead short), then a one minute recovery time. Many e .......
219: High Efficiency Speaker Asylum, Re: To a certain extent (0.00)
Posted by Tom Dawson on 2006-01-13, 16:24:59 (164.54.52.49)
When used for audio coupling and in filter applications. .......
220: High Efficiency Speaker Asylum, Re: BD15 link here (0.00)
Posted by Tom Dawson on 2006-01-13, 16:23:27 (164.54.52.49)
While I have to admit that the BD15 would be near or at the top of my list of modern production drivers that I would consider for a speaker project, I think I have some ideas that would result in a dr .......
221: High Efficiency Speaker Asylum, Re: To a certain extent (0.00)
Posted by Tom Dawson on 2006-01-13, 16:11:06 (164.54.52.49)
My impression is that, largely due to the currents they carry and often exposure to SPL, the audible differences of these components are exacerbated. Wrt non-air cored inductors, among the best I've h .......
222: High Efficiency Speaker Asylum, The amp and preamp were of a nondescript nature as befits the emphasis that I place on them.=cheap 'lytics sound dandy? (0.00)
Posted by Tom Dawson on 2006-01-13, 15:19:46 (164.54.52.49)
Just curious whether you also don't believe there's any audible merit to high performance xover components. Btw, none of this should indicate that I hold your ideas & research wrt waveguide flares in .......
223: High Efficiency Speaker Asylum, No, I'm correct because I'm disputing your misstatement that JBL asserted no audible diff between mud, alnico (0.00)
Posted by Tom Dawson on 2006-01-13, 14:58:23 (164.54.52.49)
These are the very words you posted to which I responded: "If there are audible differences between ferrite and alnico" To my knowledge this has not been proven and in fact the only "scientific" stu .......
224: Tube DIY Asylum, Maybe secret ingredients? (0.00)
Posted by Tom Dawson on 2006-01-12, 20:32:34 (4.159.238.182)
Mildly curious. .......
225: High Efficiency Speaker Asylum, Re: Tom the results of the study are in the link I posted (0.00)
Posted by Tom Dawson on 2006-01-12, 19:40:25 (4.159.238.182)
Well, Earl is implicitly excluding such ameliorations as SFG. His claim is 'no difference', not differences that can be compensated for. .......
226: High Efficiency Speaker Asylum, "only "scientific" study that I know of was done at JBL and they concluded ..,no audible difference." Then why SFG & (0.00)
Posted by Tom Dawson on 2006-01-12, 19:33:24 (4.159.238.182)
shorting rings. I won't hold my breath expecting you to acknowledge the much greater sensitivity of mud magnet TS parameters vs alnico wrt temperature and flux either. I can recognize an assumption hu .......
227: High Efficiency Speaker Asylum, Alnico advantages (0.00)
Posted by Tom Dawson on 2006-01-12, 08:50:32 (164.54.52.49)
Alnico is unique in having the most stable flux versus both temperature and modulation of any commercially available permanent magnet material and this by a wide margin. Just don't blitzkrieg it with .......
228: Tape Trail, Re: The Best of Luck to you! (0.00)
Posted by Tom Dawson on 2006-01-11, 18:55:23 (4.159.225.245)
While the focused head gap technology is undoubtedly the best there was, I was able to get almost the same effect with a form of (all tube) HX bias modulation (400khz bias frequency) using conventiona .......
229: High Efficiency Speaker Asylum, Re: First Order, huh? (0.00)
Posted by Tom Dawson on 2006-01-11, 13:14:30 (164.54.52.49)
I should mention that this xover also includes the basic first order series capacitor to block DC and to set (in conjunction with the notch) the minimum stop band rejection for the overall filter (I u .......
230: High Efficiency Speaker Asylum, Re: The high point of my first CES -- a close encounter of the Cogent kind (0.00)
Posted by Tom Dawson on 2006-01-11, 08:04:36 (164.54.52.49)
How do you imagine adding digital time alignment could possibly have any effect on the distortion you claim you heard from the Saint-Saens Organ Symphony played on these speakers since you appear not .......
231: High Efficiency Speaker Asylum, Re: First Order, huh? (0.00)
Posted by Tom Dawson on 2006-01-11, 07:21:28 (164.54.52.49)
I call it quasi-first order since it acts like a higher order filter in the stop band. I use polypropylenes. I don't have the schematic readily to hand, unfortunately, but in this case, I used an indu .......
232: High Efficiency Speaker Asylum, Re: TAD TD-4001 Passive Crossover Suggestions Wanted! (0.00)
Posted by Tom Dawson on 2006-01-10, 20:45:59 (4.158.93.95)
With my TD-4001s, I implemented a quasi first order xover with a zero (notch) in the stopband about an octave and a half below the xover frequency (400hz into a 225 hz tractrix concrete flare). I thin .......
233: Hi-Rez Highway, Agree that it's important (0.00)
Posted by Tom Dawson on 2006-01-08, 20:57:47 (4.158.126.2)
The idea that the ultrasonic range is not significant is nothing much more than an artefact from Sony's old 'Perfect Sound Forever' advertising campaign touting CDs which are notorious for top octave .......
234: Tubes Asylum, Re: Mixing SS & Tube amps (0.00)
Posted by Tom Dawson on 2006-01-08, 20:16:48 (4.158.126.2)
If using an active xover, I'd definitely do the xover with tubes. Well chosen solid state can do a decent job for the bottom two octaves. .......
235: Tube DIY Asylum, Re: effect of melted solder lead. (0.00)
Posted by Tom Dawson on 2006-01-08, 19:51:44 (4.158.126.2)
You're on the edge of failure. Unless there is some overwhelming reason to go to 6080, stay with 5998. If there is some overwhelming reason to change, have the circuit redesigned appropriately. ::: TO .......
236: High Efficiency Speaker Asylum, Bet it really thumps, though. nt (0.00)
Posted by Tom Dawson on 2006-01-08, 19:28:05 (4.158.126.2)
whoom whoom .......
237: Tape Trail, Re: Saki Glass Ferrite Heads (0.00)
Posted by Tom Dawson on 2006-01-05, 10:08:20 (164.54.52.49)
Hi - When I ran the Saki heads at 30ips, I recall they started rolling off below 25hz and there was a db to a db and a half or so head bump at around 30 hz. When I ran the bias frequency tests, I note .......
238: High Efficiency Speaker Asylum, Re: Now THAT is a freakin' Power Supply! (0.00)
Posted by Tom Dawson on 2005-12-31, 20:18:46 (4.158.93.251)
Hi, Paul - I should first probably clarify that I meant that the effective supply capacitance multiplication I referred to was due to the impedance divider ratio between the series resistance of the o .......
239: High Efficiency Speaker Asylum, Re: Myth: high-efficiency low-power (0.00)
Posted by Tom Dawson on 2005-12-30, 02:19:37 (4.159.237.227)
I've always felt having a robust power supply, particularly wrt lots of filtering and low impedance or a stiff regulator is important and have designed my equipment accordingly. For instance, I've fou .......
240: Tubes Asylum, Re: How do I improve my listening ability? (0.00)
Posted by Tom Dawson on 2005-12-29, 23:36:55 (4.158.51.191)
Nothing wrong with using a cheap DVD player for CD, IMO. When I first tried CDs on my fairly low end Panasonic DVD player several years ago, I thought it sounded preferable to my existing Carver CD pl .......
241: Tubes Asylum, Re: This is total BS!!! (0.00)
Posted by Tom Dawson on 2005-12-22, 15:48:31 (164.54.52.49)
I think Jimi repopularized tube guitar amplifiers with his playing style at the time. Even if one of his effects boxes had a germanium semiconductor in it doesn't give cruddy solid state amp distortio .......
242: Propeller Head Plaza, Re: More answers (0.00)
Posted by Tom Dawson on 2005-12-22, 15:09:41 (164.54.52.49)
Lower order distortion products are easier for listeners to integrate into the intended listening experience, partly because they have analogues, if you will, with real world phenomena that hearing me .......
243: Propeller Head Plaza, Re: More answers (0.00)
Posted by Tom Dawson on 2005-12-22, 13:34:19 (164.54.52.49)
Much perceived musical amplifier quality resides in the 'first watt' which is barely characterized in standard measurement protocols. This is where high levels of feedback provides a bandaid to partia .......
244: High Efficiency Speaker Asylum, Re: Never Tried it...NE5534, etc can "just one" be heard ? (0.00)
Posted by Tom Dawson on 2005-12-22, 13:18:54 (164.54.52.49)
Actually, it is amazingly non-fatiguing, considering the levels I play it at, and that the sound is hardly lacking in dynamics or punch. I'll go two-three hours sometimes at an average maximum level w .......
245: High Efficiency Speaker Asylum, Re: Never Tried it...NE5534, etc can "just one" be heard ? (0.00)
Posted by Tom Dawson on 2005-12-22, 10:15:54 (164.54.52.49)
Hi, Freddy - It's not perfect, but it's a pretty good sounding phono preamp, if I say so myself:). I have a little residual hum I've been meaning to get rid of, and the RIAA feedback values are compat .......
246: High Efficiency Speaker Asylum, Gimme some o them ultra-slick highs from that new K-Coupled tweeter:) (0.00)
Posted by Tom Dawson on 2005-12-22, 10:00:35 (164.54.52.49)
New vistas of K-coupling here, it looks like. .......
247: High Efficiency Speaker Asylum, Re: Never Tried it...NE5534, etc can "just one" be heard ? (0.00)
Posted by Tom Dawson on 2005-12-22, 09:18:06 (164.54.52.49)
I concur with this. I have also heard the difference (in dynamics) when I did nothing but drop the supply voltage on my phono preamp from 375V to 325Vdc (each channel independent tranny & CLC (C's GEM .......
248: High Efficiency Speaker Asylum, Re: Be Careful (0.00)
Posted by Tom Dawson on 2005-12-21, 18:44:49 (4.159.236.251)
Hi - Best not to swallow hydrogen peroxide. It didn't take much to start giving me an upset stomach - the drugstore stuff not poisonous but just really good at killing stomach bacterial flora and fizz .......
249: Propeller Head Plaza, Does an inability to geek out over MP3 partly due to my own experience w telecom codecs disqualify me as an objectivist? (0.00)
Posted by Tom Dawson on 2005-12-21, 18:02:52 (4.159.236.251)
Not to mention vocoders. .......
250: High Efficiency Speaker Asylum, Re: Never Tried it... (0.00)
Posted by Tom Dawson on 2005-12-21, 17:46:46 (4.159.236.251)
be interesting to hear how much is lost in digital recording of LP then playback though horn system (including spatial stuff like ticks, pops) Out of curiousity, I powered up one of my last solid sta .......
251: High Efficiency Speaker Asylum, Never heard anybody call electrolytic caps 'sonically invisible'. Does that help? (0.00)
Posted by Tom Dawson on 2005-12-21, 17:37:13 (4.159.236.251)
Just guessing the DEQX uses several in the audio path. .......
252: High Efficiency Speaker Asylum, Re: Be Careful (0.00)
Posted by Tom Dawson on 2005-12-21, 17:23:51 (4.159.236.251)
Hi, Freddy - Have you tried the hydrogen peroxide solution I mentioned down thread? It may take a little while to be completely effective, but I've been completely gum infection and receding gum free .......
253: Tubes Asylum, Re: What is it that makes tube amps sound so big and spacious? (0.00)
Posted by Tom Dawson on 2005-12-20, 09:26:29 (164.54.52.49)
Nope. For tube amps a lower than optimal damping factor for the speaker/setup can create part of such an effect or inadequate power supply filtering can reduce transient impact at higher output levels .......
254: High Efficiency Speaker Asylum, Re: ot - ill - need advice (0.00)
Posted by Tom Dawson on 2005-12-19, 12:46:34 (164.54.52.49)
Whoah, there, Freddy! Don't know if I can help with the rest, but I've stopped gum infections cold for the last twelve years by flossing and gargling with a capful of 3% hydrogen peroxide solution onc .......
255: Tube DIY Asylum, Re: Shunt Reg? (0.00)
Posted by Tom Dawson on 2005-12-19, 09:19:09 (164.54.52.49)
What do you think of ferroresonant transformers as regulators? .......
256: Tube DIY Asylum, Re: Eric Barbour of Svetlana published a construction article. (0.00)
Posted by Tom Dawson on 2005-12-19, 09:07:06 (164.54.52.49)
Thanks. I'll see if I can locate the article. One of my designs uses a 6BL7 in a location where linearity is quite important and I had been considering trying a 6BX7 in its place, thinking that the lo .......
257: Propeller Head Plaza, Crackerbonics (0.00)
Posted by Tom Dawson on 2005-12-16, 15:37:08 (164.54.52.49)
I thought 'yow'un' was the singular of 'y'all'. Shows what I know. .......
258: Tube DIY Asylum, Re: The 6BX7 is not a very good performer distortion wise. (0.00)
Posted by Tom Dawson on 2005-12-16, 09:33:53 (164.54.52.49)
Just wondering. How were these relative characteristics of the 6BX7 and 6BL7 determined: from plate curves or actual measured performance? .......
259: Tube DIY Asylum, Re: Voltage doublers and film caps (0.00)
Posted by Tom Dawson on 2005-12-16, 09:31:19 (164.54.52.49)
Metallized films are fine for PS use They have the advantage of being self clearing in case of breakdown, unlike films and foils. .......
260: Tube DIY Asylum, Re: Air variable capacitors are cool (0.00)
Posted by Tom Dawson on 2005-12-15, 14:20:06 (164.54.52.49)
What a coincidence! Your circuit general topology and RIAA feedback values are very close to mine or the same. I'm sure your phono preamp is one of the top performers sonically in existence. ::: TOPIC .......
261: Propeller Head Plaza, Call it JJ's Rubber Room? Jes' funnin', y'all:):)nt (0.00)
Posted by Tom Dawson on 2005-12-15, 14:08:41 (164.54.52.49)
'Tis the Season, after all. .......
262: Propeller Head Plaza, Relevance of cost effective engineering paean to high quality audio? (0.00)
Posted by Tom Dawson on 2005-12-15, 11:06:34 (164.54.52.49)
Worth questioning every time. Not that I haven't considered one of these Pannies for a HT backup amp in my weaker moments. .......
263: Tube DIY Asylum, Air variable capacitors for audio (0.00)
Posted by Tom Dawson on 2005-12-13, 10:00:34 (164.54.52.49)
I'm thinking about trying a couple of air variable capacitors (set to a fixed value) for my home brew phono preamp eq circuit. Anybody try these before for a similar application? I already have a coup .......
264: Propeller Head Plaza, Re: Consider also mechanical vibration of the fusible wire. (0.00)
Posted by Tom Dawson on 2005-12-13, 09:42:35 (164.54.52.49)
Wow! All good reasons to do without fuses in the signal path, if at all possible. I'm glad I was able to get away with merely fusing the output supply rails in my DC Coupled OTL amplifier for each cha .......
265: Propeller Head Plaza, Re: Y'all are dodging... (0.00)
Posted by Tom Dawson on 2005-12-12, 07:26:22 (164.54.52.49)
I always thought an FM modulated optical audio disc would have provided the best of both worlds of analog and digital as a consumer medium. It could provide excellent distortion and frequency response .......
266: Propeller Head Plaza, Re: Maybe it goes back to an industry that does not care about quality. Or maybe didn't know their asses from their eard (0.00)
Posted by Tom Dawson on 2005-12-08, 21:56:01 (4.158.126.72)
Hi, Tre' I saw on a website (don't have the url at hand) a paper detailing where recording professionals were evaluating with a configurable 24 bit codec and DSP engine the effects on the sound of dif .......
267: Tweakers' Asylum, Dead man posting. (0.00)
Posted by Tom Dawson on 2005-12-08, 20:39:31 (4.158.126.72)
There are indeed non magnetic stainless steel alloys. .......
268: Tube DIY Asylum, What the world needs is a good $5 teflon capacitor:) nt (0.00)
Posted by Tom Dawson on 2005-12-08, 20:24:34 (4.158.126.72)
heh .......
269: High Efficiency Speaker Asylum, "To me woofers today are so much better than years ago, its kind of mo contest." Some are, some aren't (0.00)
Posted by Tom Dawson on 2005-12-08, 20:08:49 (4.158.126.72)
While the JBL 2226 is one of the best of the 'new' woofers, it doesn't do as well above 250hz in critical listening applications as many older and technically less distinguised drivers. I believe some .......
270: Propeller Head Plaza, Maybe it goes back to an industry that does not care about quality. Or maybe didn't know their asses from their eardrums (0.00)
Posted by Tom Dawson on 2005-12-08, 19:37:16 (4.158.126.72)
I just got finished playing some of the highly touted sonically (at the time) CBS Mastersound pressing of the digitally recorded and half speed mastered 'Weather Report' by Weather Report. In reality, .......
271: Propeller Head Plaza, Re: I don't know what tapes you are talking about. (0.00)
Posted by Tom Dawson on 2005-12-08, 08:12:54 (164.54.52.49)
Where I own both a CD and LP version of a given recording, differences in frequency balance are most usually not very significant with my playback setup except that the CD high end is sometimes a bit .......
272: Tube DIY Asylum, Re: I love tube OTL.... (long) (0.00)
Posted by Tom Dawson on 2005-12-07, 15:38:50 (164.54.52.49)
I've never heard the KEF version, but I understand it was about the best, certainly better than the Rogers. I've still got my Chartwells (although with newer B110's). Don't know if it was reall the th .......
273: Tweakers' Asylum, It's more profitable to sell undersized lumber (0.00)
Posted by Tom Dawson on 2005-12-06, 22:08:29 (4.159.236.142)
I used to live in a house built in the late nineteenth century. Its 2" wide dimensional lumber was really 2". .......
274: Tube DIY Asylum, Re: SoniCap Gen 1s, 10µF/200 for $18. (0.00)
Posted by Tom Dawson on 2005-12-06, 21:49:41 (4.159.236.142)
Thanks. I'll check them out head to head against the thetas. .......
275: Tube DIY Asylum, Re: But I think I do hear it's there. (long) (0.00)
Posted by Tom Dawson on 2005-12-06, 21:48:06 (4.159.236.142)
Hi - I've had somewhat similar experiences with my DC Coupled OTL (it is triode throughout the signal path), losing a couple of woofers from Chartwell LS3-5As, but because the outputs are tube thus mo .......
276: Tube DIY Asylum, Capacitor recommendation? (0.00)
Posted by Tom Dawson on 2005-12-05, 20:33:37 (4.158.51.91)
I'm looking for caps to upgrade my DC Coupled OTL. A particularly critical one is in the shunt leg of the feedback path (reduces gain to unity at DC) - I don't have the guts to torture my woofer's VCs .......
277: High Efficiency Speaker Asylum, VC question (0.00)
Posted by Tom Dawson on 2005-12-05, 19:52:43 (4.158.51.91)
Anybody happen to know how many actual turns (n) in 2220 voice coil winding for, say 8 or 16 ohm version, and or effective wire gauge? TIA - Tom Dawson .......
278: High Efficiency Speaker Asylum, "Speak now or forever hld your peace." Well, since you put it that way.... (0.00)
Posted by Tom Dawson on 2005-12-05, 19:36:30 (4.158.51.91)
you have stated that the OS flare gives lowest HOMs. Is this an absolute statement for all frequencies where the flare is effective, or can it be modified to futher reduce HOMs over certain fundamenta .......
279: Propeller Head Plaza, Geez-o-weez! Just check any prosound mixer or recorder on the market. Even the cheap ones are 24 bit (0.00)
Posted by Tom Dawson on 2005-12-05, 13:07:22 (164.54.52.49)
16 bits gets you laughed at in the recording industry nowadays. .......
280: Propeller Head Plaza, "Lots" of magnificent recordings on CD? Not to my ears. (0.00)
Posted by Tom Dawson on 2005-12-05, 12:43:18 (164.54.52.49)
LPs are far from being without problems, but they are not generally flat sounding with poor to mediocre musical detail and imaging and either unnatural sounding, lifeless, or ear burners like most CDs .......
281: Propeller Head Plaza, CD rising quantization distortion over lowest 30db several percent or more=bad sonic news (0.00)
Posted by Tom Dawson on 2005-12-04, 15:59:15 (4.158.93.58)
That doesn't leave enough dynamic range for Redbook to be useable for decent SQ recording as the pros have acknowledged en masse for going on a decade now. This is a distortion mechanism which does no .......
282: Propeller Head Plaza, Re: Never heard any 'fabulous' 16 bit PCM. nt (0.00)
Posted by Tom Dawson on 2005-12-03, 21:52:05 (4.159.230.141)
I don't deny that optimized outliers exist for some CDs that sound fairly decent. How about the rest of us? Too bad there isn't more support for higher quality digital like SACD and DVDA. Most everybo .......
283: Propeller Head Plaza, CDs are sonically inferior in microdynamics, rendering musical timbres,etc.. (0.00)
Posted by Tom Dawson on 2005-12-03, 21:42:27 (4.159.230.141)
It wouldn't surprise me in the least that sufficient parsing will also find MP3's that some would call 'wonderful sounding' if one puts himself into the proper mindset. Don't assume I share your reduc .......
284: Propeller Head Plaza, Never heard any 'fabulous' 16 bit PCM. nt (0.00)
Posted by Tom Dawson on 2005-12-02, 09:26:22 (164.54.52.49)
. .......
285: High Efficiency Speaker Asylum, Re: Horn theory discussion (background) (0.00)
Posted by Tom Dawson on 2005-12-02, 09:05:09 (164.54.52.49)
Aside from the fact that phase plugs improve this, is there some specific unique diaphragm or wavefront throat profile for each flare that minimizes HOM's 'up front', if you will? .......
286: High Efficiency Speaker Asylum, Tract-O-Cat Compromise flare? (0.00)
Posted by Tom Dawson on 2005-12-02, 08:46:52 (164.54.52.49)
Battle of the 'Titans', if you will? Sorry. I couldn't resist. .......
287: Propeller Head Plaza, Re: Simply get samples of early players and listen to them with modern 'audiophile' quality CDs. ... (0.00)
Posted by Tom Dawson on 2005-11-30, 10:02:07 (164.54.52.49)
I'm certainly not opposed to digital per se. If we are talking SACD or DVD-A SQ throughout the recording/playback chain instead of Redbook, I wouldn't be complaining too much. But my paradigm is diffe .......
288: Propeller Head Plaza, Re: Why early digital sounded so bad (0.00)
Posted by Tom Dawson on 2005-11-30, 08:05:35 (164.54.52.49)
I've got the Firebird and the 1812 Overture and I must say while the micing and mixing were exceptionally well done on them, the transfers to disc are not nearly as clean relative to the earlier direc .......
289: Propeller Head Plaza, Re: Why early digital sounded so bad (0.00)
Posted by Tom Dawson on 2005-11-29, 10:54:21 (164.54.52.49)
The 'analog master' equalization canard you post is exactly what would be expected of the shills pushing 'perfect sound forever' at the time to excuse the execrable quality of early digital offerings. .......
290: Propeller Head Plaza, What do you not understand about the potential interchannel sampling timing error of a transition of arbitrary size? (0.00)
Posted by Tom Dawson on 2005-11-24, 22:00:29 (4.131.15.212)
I said nothing about dithering depending on what you claim. And a weak protest of 'It just ain't so' does not cut it. Produce your panacea, if you will, but try not insulting our intelligence by clai .......
291: Propeller Head Plaza, 'Fraid it is. Your argument fails due to its absolute dependence on extremely long spectral timing averaging requirement (0.00)
Posted by Tom Dawson on 2005-11-23, 07:16:49 (164.54.52.49)
And it's not reasonable to slavishly equate the ear-brain hearing mechanism to measurements tweaked to make marginal quantization practices look good. 'Perfect Sound Forever'? Sheesh. .......
292: General Asylum, Re: I've got a mid-'70's Sony SQ4 LP decoder. Does that count? nt (0.00)
Posted by Tom Dawson on 2005-11-22, 07:14:19 (164.54.52.49)
heh .......
293: Tube DIY Asylum, Re: Another aluminum wire mesh tube damping upgrade. (0.00)
Posted by Tom Dawson on 2005-11-22, 07:07:15 (164.54.52.49)
Thanks for the suggestions. These tubes already have the O-rings installed, btw. I'll probably look into adding some damping material such as you mention to my amp and preamp chassis fairly soon. ::: .......
294: Tube DIY Asylum, Re: Where did you get the material? (0.00)
Posted by Tom Dawson on 2005-11-22, 07:04:35 (164.54.52.49)
McMaster-Carr sells this. I ordered 1 foot by 2 foot pieces from them. .......
295: High Efficiency Speaker Asylum, 'WOW!!" meaning.....what? (0.00)
Posted by Tom Dawson on 2005-11-21, 23:45:28 (4.159.238.50)
Didn't 'Wow' come just before 'Vavoom' in the early '40's? .......
296: Tube DIY Asylum, Another aluminum wire mesh tube damping upgrade. (0.00)
Posted by Tom Dawson on 2005-11-21, 23:30:06 (4.159.238.50)
This evening I finally got around to putting aluminum wire mesh damping over my preamp tubes. I initially figured that since the preamp tubes were already shock mounted on a 3/16" sheet of aluminum an .......
297: Tubes Asylum, Re: tube dampers (0.00)
Posted by Tom Dawson on 2005-11-18, 09:01:25 (164.54.52.49)
As an experiment in tweakery, I've done something that turned out to work very well on my DC coupled OTL amplifier that has a number of hot running 6AS7Gs which might be difficult (or expensive) to da .......
298: High Efficiency Speaker Asylum, Re: Bass advice (0.00)
Posted by Tom Dawson on 2005-11-16, 12:42:36 (164.54.52.49)
The two main things to look out for with an ELF design are 1) select a driver that has good excursion and (if possible) linear suspension to minimize distortion below its resonance (although a closed .......
299: High Efficiency Speaker Asylum, Re: Bass advice (0.00)
Posted by Tom Dawson on 2005-11-16, 10:31:04 (164.54.52.49)
Hi - I think Freddy has an excellent suggestion to start with. Then when you get your SP1 bass extension flat to something reasonable like 40-50 hz you could augment with maybe a ported ELF type sub b .......
300: Propeller Head Plaza, Re: Now, y'all hold on there. (0.00)
Posted by Tom Dawson on 2005-11-15, 22:21:05 (4.158.126.135)
Worst case is one clock cycle in each direction (+/- 22uS for RBCD). If a transition is caught one sample cycle earlier on one channel relative to the other one when the actual waveform timing is near .......
301: Propeller Head Plaza, Re: Now y'all hold on. (0.00)
Posted by Tom Dawson on 2005-11-15, 14:03:27 (164.54.52.49)
There certainly are, as regards the limits of human perception which can detect interchannel delay differences of as low as 2 microseconds over a wide dynamic range. Even optimal dithering will give o .......
302: Propeller Head Plaza, Re: Goodness, Gracious! (0.00)
Posted by Tom Dawson on 2005-11-15, 11:34:01 (164.54.52.49)
What y'all find out is that the loss of phase information is just the same as if noise was added, and that it's way, way, below the sources of phase irregularities from other sources. This is not tru .......
303: General Asylum, "What makes audio unique in all the world of subjective assesment that it needs a unique approach?" (0.00)
Posted by Tom Dawson on 2005-11-14, 10:32:07 (164.54.52.49)
Well, unlike wine tasting and many other forms of subjective assessment which are direct evaluations by human senses, the validity of audio DBT typically is dependent on an entire playback chain (and .......
304: General Asylum, "(Bose caters) to the wants of the people no matter what it sounds like."...whaa? (0.00)
Posted by Tom Dawson on 2005-11-14, 10:14:39 (164.54.52.49)
No audio manufacturer expends more effort than Bose in attempting to alter the audio expectations of its propective customer base as part of its marketing campaign....usually for the worse, I might ad .......
305: High Efficiency Speaker Asylum, Re: My Accident (0.00)
Posted by Tom Dawson on 2005-11-14, 07:40:40 (164.54.52.49)
Very sorry to hear that. Hope you're 100% soon. .......
306: High Efficiency Speaker Asylum, Re: Mono off center corner bass? (0.00)
Posted by Tom Dawson on 2005-11-14, 07:31:16 (164.54.52.49)
A friend of mine once had a mono sub xovered at 100hz in a corner behind his left speaker. On FM, centered male announcer seemed to be pushed at least a foot over to the left with an eight foot speake .......
307: Propeller Head Plaza, Re: Wow, what's this? A real technical question. (0.00)
Posted by Tom Dawson on 2005-11-11, 07:31:05 (164.54.52.49)
While dithering in combination with noise shaping can (real world) significantly reduce quantization distortion, it is at the expense of both reducing the bandwidth over which the reduction can be ind .......
308: Propeller Head Plaza, Re: Hmmm... (0.00)
Posted by Tom Dawson on 2005-11-10, 15:52:53 (164.54.52.49)
The third and and perhaps fifth order harmonic components are probably related to the lsb quantization error. The measured even order components are probably the result of the system noise floor and d .......
309: General Asylum, Re: YUM (0.00)
Posted by Tom Dawson on 2005-11-10, 10:03:36 (164.54.52.49)
Probably would have been interesting to be a fly on the tacos at the executive meeting where they changed the name from 'Tricon Global' to 'Yum'. Pretty spirited discussions about target markets, spin .......
310: General Asylum, Just count yourself lucky that apparently nobody's tipped him off about the '"Clever" Little Clock' yet. (0.00)
Posted by Tom Dawson on 2005-11-10, 09:49:11 (164.54.52.49)
Snerk! .......
311: General Asylum, "Pure shite." - Somebody obviously isn't working hard enough on his ad copy. (0.00)
Posted by Tom Dawson on 2005-11-10, 09:40:44 (164.54.52.49)
Har De Har Har! .......
312: General Asylum, Bad bug juice formula? (0.00)
Posted by Tom Dawson on 2005-11-10, 09:37:42 (164.54.52.49)
Were the caps you swapped out all Nichicons? .......
313: High Efficiency Speaker Asylum, Re: Thoughts on amplifier power, amplifier type, and high efficiency speakers (0.00)
Posted by Tom Dawson on 2005-11-09, 13:54:42 (164.54.52.49)
I run an all triode fully balanced DC coupled OTL of my own design in my hi-end stereo, and it still retains most of the sonic benefits of standard triode tube amp implementations. I believe this is b .......
314: Propeller Head Plaza, Re: An actual technical post/question, just for a change of pace.... (0.00)
Posted by Tom Dawson on 2005-11-09, 13:32:24 (164.54.52.49)
I don't have a complete handle on the situation, but my impression is that a lot of these assertions about dither result from the time averaging characteristics of spectrum analysis equipment rather t .......
315: High Efficiency Speaker Asylum, Re: anyone thinking of changing wires in speaker to match quality of cables? even direct from horn to amp... (0.00)
Posted by Tom Dawson on 2005-11-07, 00:40:07 (4.131.12.123)
I don't see the harm in experimenting a little. You could even tailor the wire inside the cabinet to each type of driver. One thing to keep in mind is that wire inside a cabinet will probably be subje .......
316: OTL Asylum, Re: Audiogon thread blocking (0.00)
Posted by Tom Dawson on 2005-11-04, 18:44:34 (4.158.126.97)
AFAIK, registered inmates can delete their most recent post in a thread within 24 hours of posting it if nobody else has replied. .......
317: High Efficiency Speaker Asylum, Re: TAD MTM Cabinets (0.00)
Posted by Tom Dawson on 2005-11-04, 09:45:51 (164.54.52.49)
Just curious. What's the 'new stuff'? Still high efficiency? - regards Tom Dawson .......
318: Water Cooler, However, this reduction in illness becomes more dramatic the later you die. (0.00)
Posted by Tom Dawson on 2005-11-03, 18:35:22 (4.158.51.218)
Just thought I'd mention that. .......
319: Water Cooler, Re: Nature or nurture - both (0.00)
Posted by Tom Dawson on 2005-11-03, 11:15:54 (164.54.52.49)
As someone who has been chased by two pit bulls while running as the owner looked on and said nothing and who has had a sister who was slashed by a doberman pinscher on a leash, I'm in favor of restri .......
320: Water Cooler, Quite believable (0.00)
Posted by Tom Dawson on 2005-11-03, 11:01:43 (164.54.52.49)
Anyone who's serious about foreign policy doesn't believe resorting to bluster and immediately backing down with nearly 200,000 troops in place under UN auspices is good for anything. Since, among oth .......
321: Water Cooler, Re: If I recall... (0.00)
Posted by Tom Dawson on 2005-11-03, 08:30:06 (164.54.52.49)
Historians will look at the Iraq war as 'Bush's Folly'. The good news is that, no matter how badly things turn out in Iraq, they will always be put in the shade by the US fumbling in Vietnam. IAC, I .......
322: High Efficiency Speaker Asylum, Re: Recommendations for woofers to go with JBL compression drivers and horns (0.00)
Posted by Tom Dawson on 2005-11-02, 15:56:20 (164.54.52.49)
Would a floorstanding tower system with 3 12's in a 'half line array' be an option? That could put your 2446/2385 right at listening height and give you superior bass efficiency and/or extension witho .......
323: General Asylum, Re: Do musicians have a better sense of "real" sound? (0.00)
Posted by Tom Dawson on 2005-11-02, 15:08:17 (164.54.52.49)
I'm not a 'real' musician, but I think that while trained musicians can be among the most perceptive of audiophiles because of their appreciation of what makes good music(al sound), they can also be t .......
324: General Asylum, ...not at all (0.00)
Posted by Tom Dawson on 2005-11-02, 14:46:21 (164.54.52.49)
I'm perfectly willing to try such 'tweaks'. I just refuse to line their purveyors' pockets, using reasoning similar to that by which I've never purchased a Lotto ticket in my life because I oppose sta .......
325: General Asylum, "...dramatic improvement upon stunning effectiveness. How much more can we expect?" Claims of Perfect Sound Forever..? (0.00)
Posted by Tom Dawson on 2005-11-02, 11:08:17 (164.54.52.49)
No over the top praise from the wilfully self-deluding would surprise me. .......
326: General Asylum, Barnumology (0.00)
Posted by Tom Dawson on 2005-11-02, 10:48:37 (164.54.52.49)
The names "Intelligent Chip" and "Clever Little Clock" are tipoffs that what is going on here are charlatans abusing both science and their customers' intellectual needfulness to push their snake oil .......
327: High Efficiency Speaker Asylum, Re: Attaching compression drivers to homebrew tractrix horns (0.00)
Posted by Tom Dawson on 2005-11-01, 12:55:10 (164.54.52.49)
With my concrete tractrix horns, I attached a 3/8" thick brass mounting plate to the horn with four pieces of 5/16" x 18" long threaded brass rod stock screwed into the backplate and cast directly int .......
328: High Efficiency Speaker Asylum, Re: Zu Druid question (0.00)
Posted by Tom Dawson on 2005-11-01, 10:15:13 (164.54.52.49)
I haven't heard them, but my impression strictly from the response curves would be more that the Zruids become progressively weaker in the bass below 200 hz more than sound particularly bright. And th .......
329: General Asylum, Re: Time to call it quits? (0.00)
Posted by Tom Dawson on 2005-10-28, 22:01:42 (4.158.93.78)
May be time to look into a high quality high efficiency two way system that could use a little lf boundary reinforcement with a horn HF driver that's fairly directional so as to not be overly affected .......
330: High Efficiency Speaker Asylum, Re: Druid soundstage mag. measurements (0.00)
Posted by Tom Dawson on 2005-10-27, 11:50:36 (164.54.52.49)
"What's this tell you?" Well, I'm not seeing 40 hz at 100db/w/m, or 90....or even 80..... .......
331: High Efficiency Speaker Asylum, Re: Thanks Tom, one more question... (0.00)
Posted by Tom Dawson on 2005-10-25, 08:24:51 (164.54.52.49)
Time alignment improves the naturalness and detail you hear, IMO. I agree that you don't want to complicate your xover to achieve it if you don't have to. I've been getting good results while keeping .......
332: High Efficiency Speaker Asylum, Re: Tom, would you mind explaining that a little? (0.00)
Posted by Tom Dawson on 2005-10-25, 07:42:24 (164.54.52.49)
Hi, Dave - Basically, yes. The radiation pattern should be considered relative to the mouth (more or less) of the horn, and the delay from the HF driver diaphragm. But I don't see much of problem if t .......
333: Tube DIY Asylum, Re: Lead-Free Solder (0.00)
Posted by Tom Dawson on 2005-10-24, 09:30:00 (164.54.52.49)
Some might. I've been using lead free Kester SN96 Ag4 rosin flux for a long time for all my home audio projects. Works fine with an 800 F soldering iron tip. .......
334: Propeller Head Plaza, Well, yewall got it wrong. (0.00)
Posted by Tom Dawson on 2005-10-24, 09:06:28 (164.54.52.49)
My statement wrt 'false negatives' was premised on what a meter reader techno type might produce who at least had the minimal level of competence needed to correct for level and first order amplitude .......
335: High Efficiency Speaker Asylum, Re: I am glad you said that. (0.00)
Posted by Tom Dawson on 2005-10-24, 08:59:59 (164.54.52.49)
Wrt the 'radiating plane', that does not cancel out the delay due to the speed of sound between the throat and that location. If such were the case, the 2nd order distortion characteristic of HF horns .......
336: Propeller Head Plaza, Thanks for the explanation. (0.00)
Posted by Tom Dawson on 2005-10-21, 10:22:36 (164.54.52.49)
My experience correlates well with what you say. It's all too easy to obtain false negatives with inadequately applied double blind testing, and I've always suspected DBT is too difficult to do suffic .......
337: High Efficiency Speaker Asylum, Re: Theoretical Question on speaker Fs (0.00)
Posted by Tom Dawson on 2005-10-21, 08:22:06 (164.54.52.49)
Besides the points that hollowboy mentions, the effective excursion linearity of most drivers deteriorates quite a bit below Fs as it moves below its mass controlled frequency range to its suspension .......
338: Tech Square, Re: IIRC, record center holes (0.00)
Posted by Tom Dawson on 2005-10-21, 07:46:28 (164.54.52.49)
"I've head of at least one guy who used to oval the center hole so he could self center the LP's....a bit radical to my thinking." I've done that on occasion and it's not too difficult if you keep a s .......
339: Shady Lane, Re: This is how you close PayPal account: (0.00)
Posted by Tom Dawson on 2005-10-20, 19:48:56 (4.131.14.4)
Thanks for the info. I walked far enough through your instructions to satisfy myself that almost all the 'Paypal' emails I was getting were from the little spoof mother sh*t eaters and mother sh*t f*c .......
340: Propeller Head Plaza, Some More Choice Words... (0.00)
Posted by Tom Dawson on 2005-10-19, 18:29:23 (4.158.51.108)
...But I'd probably be better off keeping them to myself;) .......
341: Shady Lane, Re: (longish) ;) (0.00)
Posted by Tom Dawson on 2005-10-18, 19:09:48 (4.158.126.189)
Thanks for the detailed explanation, but I don't really buy that intelligent applications of Sniffer type tools couldn't isolate and trace these spoofs from whatever network nodes that they pass throu .......
342: Tube DIY Asylum, Re: Follow up with E-Linear variation Q? (0.00)
Posted by Tom Dawson on 2005-10-18, 18:09:26 (4.158.126.189)
I'm sorry, but not having direct reference to the articles you mention, I cannot comment in detail. However, obtaining positive feedback through transformer windings or taps is a useful tool in minimi .......
343: Tube DIY Asylum, Re: Positive current feedback (0.00)
Posted by Tom Dawson on 2005-10-17, 15:58:28 (164.54.52.49)
I'm using this technique to good effect with my DC Coupled (rolled off to unity gain at DC to minimize offset (given the moderate AC feedback ratio) & the chances of voice coil havoc resulting from an .......
344: Shady Lane, Re: Shut them down? (0.00)
Posted by Tom Dawson on 2005-10-17, 14:39:16 (164.54.52.49)
Paypal should find out where these scammers are operating from, then contact whichever governmental agencies has purview over such activities to shut them down. Repeatedly, if necessary. Right now, Pa .......
345: Shady Lane, Re: More Paypal scamming -- DEFINTELY (0.00)
Posted by Tom Dawson on 2005-10-17, 12:09:33 (164.54.52.49)
The fact that Paypal doesn't shut these scammers down reflects poorly on Paypal itself. It shows that Paypal has no concern for its customers beyond taking their money. .......
346: Propeller Head Plaza, Einstein: "God does not play dice (with your optical discs)." (0.00)
Posted by Tom Dawson on 2005-10-17, 10:48:55 (164.54.52.49)
So there. .......
347: High Efficiency Speaker Asylum, Re: How Important Is Time Alignment and large sculptures (0.00)
Posted by Tom Dawson on 2005-10-17, 09:28:00 (164.54.52.49)
It's one of those things that, once you experience it and realize its effect on the overall presentation of the music, you'd probably regret not designing it into a system if you had the opportunity. .......
348: Propeller Head Plaza, Re: Get off it! (0.00)
Posted by Tom Dawson on 2005-10-17, 08:46:11 (164.54.52.49)
Accuracy is in the ear of the beholder, but.... One of the things that good tubed equipment does well that I haven't yet heard from solid state or digital to the same degree is reveal nuances upstream .......
349: Propeller Head Plaza, Re: I suspect a misdirected post but no mind ... I agree completely! nt (0.00)
Posted by Tom Dawson on 2005-10-17, 07:22:13 (164.54.52.49)
Yep. Misdirected post on my part. .......
350: Propeller Head Plaza, Working toward a GUT of audio objectivism and subjectivism (0.00)
Posted by Tom Dawson on 2005-10-14, 15:35:03 (164.54.52.49)
..that would respect both peoples' perceptions and objectivism. In this way, a win-win scenario is most likely. .......
351: High Efficiency Speaker Asylum, Re: Impedence vs frequency (0.00)
Posted by Tom Dawson on 2005-10-14, 15:24:42 (164.54.52.49)
Trying to steal Hsu Research's thunder? Jes' funnin'. Do you plan to offer a kit version? .......
352: High Efficiency Speaker Asylum, Re: Lotsa bass, no boom - eminence (0.00)
Posted by Tom Dawson on 2005-10-14, 14:59:02 (164.54.52.49)
How's it going? Have you ever compared Eminence to Steel Sound's offerings? Not that there's any relevance, but I'm starting to get an itch to build a compact bookshelf 96-98db/w/m 10" woofer two way .......
353: Propeller Head Plaza, Trollin', trollin', trollin' - keep those objectivists goin' (0.00)
Posted by Tom Dawson on 2005-10-14, 14:29:06 (164.54.52.49)
"Well, the result is certainly magical at any rate... Phenomenal actually. ;-)" Hmmmm. .......
354: Propeller Head Plaza, Re: Tsk, tsk! Shame on you! Talk like that will only (0.00)
Posted by Tom Dawson on 2005-10-14, 14:24:06 (164.54.52.49)
Don - Of the posters in this thread, I believe John is just about the best qualified to comment on the veracity of the 'scientific' claims made for the GSIC, since his work deals with scientific resea .......
355: Propeller Head Plaza, Re: Ooh, what a great idea..wish I had thought of that one.. (0.00)
Posted by Tom Dawson on 2005-10-14, 12:49:23 (164.54.52.49)
Hi, John - I'm making progress on my analog setup - doing a little tube rolling - just subbed some NOS Westinghouse 5751s that I'm pretty sure are really relabled GE's for RCA black plate 12AX7's in m .......
356: Propeller Head Plaza, Re: Come on Dan - how many different $2,000 amp designs could be considered credible? (0.00)
Posted by Tom Dawson on 2005-10-14, 12:38:52 (164.54.52.49)
I'm not quite sure if you're suggesting that amplifiers (for home use)costing $2,000 or more are a waste of money because competent amps are available for considerably cheaper or whether it's merely d .......
357: Propeller Head Plaza, Re: eggzactly. (0.00)
Posted by Tom Dawson on 2005-10-14, 12:01:42 (164.54.52.49)
I missed the name of the bum who dreamed that one up. He may have shot himself in the foot though. Next week, I'm selling 'migration' copies of top selling CDs for people who want to save money by enh .......
358: Propeller Head Plaza, Why a duck? (0.00)
Posted by Tom Dawson on 2005-10-14, 09:24:04 (164.54.52.49)
"I'm fortunate enough to work with another engineer who is an audiophile. It's amazes my how we can sit and talk seemingly endlessly about how just about everything we hear about audio is bullshit. I .......
359: Propeller Head Plaza, "No one here is paid to teach you." Ok, PT Barnum... (0.00)
Posted by Tom Dawson on 2005-10-14, 08:45:48 (164.54.52.49)
Wrt my audio bona fides, they include developing an unique and patentable DC coupled OTL tube amp topology the prototype of which has been performing reliably in daily use for seventeen years now, a t .......
360: Shady Lane, More Paypal scamming? (0.00)
Posted by Tom Dawson on 2005-10-14, 08:07:46 (164.54.52.49)
I just got an email from ""PayPal" " which starts out as follows: "As part of our security measures, we regularly screen activity in the PayPal system. We recently noticed the following issue on your .......
361: Propeller Head Plaza, Re: You're pretty feisty today... (0.00)
Posted by Tom Dawson on 2005-10-14, 07:36:14 (164.54.52.49)
"Again I don't accept GKs or CJs comments relating to the chip as being anything more than their opinions/ideas on how the chip works or may work - debunking them or their comments may not, in fact mo .......
362: Propeller Head Plaza, Re: "You can't expect 100% or anything close to it." (0.00)
Posted by Tom Dawson on 2005-10-13, 10:19:04 (164.54.52.49)
"Given the responses of JA, the other JA, and ST, plus a reader's letter suggesting that I had "lost the plot," I invited one of the listeners—the most important one—back to my studio. That was Steve .......
363: Propeller Head Plaza, Re: I meant exceptional as far as standing out in the crowd. (0.00)
Posted by Tom Dawson on 2005-10-13, 09:21:49 (164.54.52.49)
The 'line' that I was referring to is that nonsensical techno-babble is offered to 'explain' the GSIC's workings. Lots of people make changes to their audio setups all the time, some of which improve .......
364: Propeller Head Plaza, Re: What's obvious to me... (0.00)
Posted by Tom Dawson on 2005-10-13, 09:06:42 (164.54.52.49)
You appear to claim that it is a matter of indifference to you whether the justifications offered for the GSICs workings are specious or fraudulent since the effects you believe it produces are of suc .......
365: Propeller Head Plaza, "So what? It throws the baby out with the bathwater." (0.00)
Posted by Tom Dawson on 2005-10-12, 14:54:49 (164.54.52.49)
More like the contents of a chamber pot. .......
366: High Efficiency Speaker Asylum, Re: Tom, I used your formulas in Excel but the solutions for X and Y don't make sense (0.00)
Posted by Tom Dawson on 2005-10-12, 14:48:16 (164.54.52.49)
I think you're right. Sorry - I just cut and pasted from the first site that looked like it had approximately correct equations. The person who wrote it did some weird angle scaling, dividing A/2 wher .......
367: Propeller Head Plaza, Re: Laugh - no it's not exceptional.... (0.00)
Posted by Tom Dawson on 2005-10-12, 12:33:19 (164.54.52.49)
Partly a play on words. 'Exceptionable' is similar in meaning to 'objectionable'. I have a high tolerance for and tend to encourage most audio subjectivism because I believe there is some veracity to .......
368: Propeller Head Plaza, Re: It is not a test procedure, it is a validation procedure (0.00)
Posted by Tom Dawson on 2005-10-12, 12:16:11 (164.54.52.49)
Probably you can obtain more similar sounding (and cheep) copies of a given CD by ripping and burning them. Make custom track selections, too. .......
369: High Efficiency Speaker Asylum, Re: Mono sub horn (0.00)
Posted by Tom Dawson on 2005-10-12, 11:41:32 (164.54.52.49)
You could make your ceiling vaulted as the final sub horn flare:). .......
370: High Efficiency Speaker Asylum, Re: Is there a formula to determine cutting and miter angles for a 4 sided horn of arbitrary length? (0.00)
Posted by Tom Dawson on 2005-10-12, 11:31:03 (164.54.52.49)
Well, here's formulae for calculating compound angles in general that you can adapt from its original application for a compound miter saw. A = Angular bend that the corner makes relative to a straigh .......
371: Tubes Asylum, Re: NOS Westinghouse 5751s (0.00)
Posted by Tom Dawson on 2005-10-12, 09:15:07 (164.54.52.49)
You've got some nice tubes there! I, however, may not have been quite so lucky. I finally found a photograph (ebay auction 5817653836) of 5751s that look almost identical (down to the acid etching) to .......
372: Tubes Asylum, Re: There are ways of improving CF performance ... (0.00)
Posted by Tom Dawson on 2005-10-11, 12:50:55 (164.54.52.49)
I used a 6BK7B in a White Follower configuration at the output of my phono preamp to minimize possible symmetry and drive problems under load. .......
373: Propeller Head Plaza, GIGO (0.00)
Posted by Tom Dawson on 2005-10-11, 11:58:01 (164.54.52.49)
They are henceforce grounded for a month in their Bose Wave Reference listening rooms. .......
374: Propeller Head Plaza, Re: I respectfully disagree with your last statement Tom... (0.00)
Posted by Tom Dawson on 2005-10-11, 10:23:22 (164.54.52.49)
Such a dramatic improvement as you claim with the GSIC should lend itself to a few simple tests such as: 1) If two seconds exposure is recommended, what is the effect of less or more time? 2) How far .......
375: Propeller Head Plaza, GSIC not a typical audio product & it is exceptionable. (0.00)
Posted by Tom Dawson on 2005-10-10, 23:08:35 (4.159.237.83)
The claptrap that is passed off as an 'explanation' for how the GSIC is supposed to 'work' is an insult to one's intelligence. .......
376: Propeller Head Plaza, Re: Understood, with one exception. (0.00)
Posted by Tom Dawson on 2005-10-10, 21:41:33 (4.159.237.83)
Those who purport to explain the workings of the GSIC 'scientifically', and they are among those who have undoubtedly attempted to 'use' it, have come up with rhetoric that is, in the end, no more pla .......
377: Tubes Asylum, NOS Westinghouse 5751s (0.00)
Posted by Tom Dawson on 2005-10-08, 21:10:29 (4.158.126.30)
The ones I got came in purplish boxes with white lettering, have gray plates and halo getters, no supporting rods or third micas, are marked in red paint '12ax7/5751' and have '5751' and 'USA' and a r .......
378: Propeller Head Plaza, Re: We already have an asylum for... (0.00)
Posted by Tom Dawson on 2005-10-07, 13:32:53 (164.54.52.49)
Certain types of capacitors, particularly electrolytics and mylars, become less lossy at somewhat elevated temperatures which should result in the perception of better sound. Not entirely coincidental .......
379: Propeller Head Plaza, Re: "Shameless or sadly pathetic?"... (0.00)
Posted by Tom Dawson on 2005-10-06, 20:07:19 (4.158.126.164)
AFAIC, the Belts are just this side of objectionable - Clever Little Intelligent Bric a Brac are a bit too shamelessly exploiting psychological needfulness. .......
380: Tube DIY Asylum, Re: New tubie needs direction (0.00)
Posted by Tom Dawson on 2005-10-06, 18:04:39 (4.158.126.164)
People have mentioned the Dyna Mk III, which is good. Or you could start with the Stereo 70, convert to triode mode, upgrade supply/input stage, get a second one & run the pair as monoblocks in bridge .......
381: Propeller Head Plaza, Accumulating returns.... (0.00)
Posted by Tom Dawson on 2005-10-05, 15:24:16 (164.54.52.49)
Maybe I should become a dealer of similar baubles. Having a few cases of them in my listening room going out the door at $150 a pop would certainly make me feel pretty good. .......
382: Tube DIY Asylum, Re: High vs average efficient speakers (0.00)
Posted by Tom Dawson on 2005-10-05, 14:12:41 (164.54.52.49)
I see a lot of good responses have already been posted, but with high efficiency speakers there's less energy relative to acoustical output to support resonance modes and more of the musical dynamic r .......
383: Tubes Asylum, Re: how to "fix" loose bass (0.00)
Posted by Tom Dawson on 2005-10-05, 13:53:07 (164.54.52.49)
Not familiar with your particular amp, but might it be something that an increase in power supply capacitance might help? Doubling the output stage supply capacitance had a dramatic effect on how a St .......
384: Propeller Head Plaza, Re: The I-Chip Hypocracy (0.00)
Posted by Tom Dawson on 2005-10-05, 08:03:57 (164.54.52.49)
I think the question comes down to what the best use of an enhanced state of audio appreciation would be (due to state of mind). It seems to me, besides general enjoyment, a likely candidate would be .......
385: Tubes Asylum, Re: How the price has risen. (0.00)
Posted by Tom Dawson on 2005-10-04, 10:32:26 (164.54.52.49)
That's an interesting subject. In the late '80's I had bought 35 GE 6LF6's for an OTL project that never materialized since I went the triode route for the prototype and stayed with that. So, about 9 .......
386: Tubes Asylum, Re: Seeking advice on budget 5751s (0.00)
Posted by Tom Dawson on 2005-10-04, 10:22:51 (164.54.52.49)
Thanks. I'll do that. .......
387: Propeller Head Plaza, Re: Excellent!!!!! (0.00)
Posted by Tom Dawson on 2005-10-03, 08:43:10 (164.54.52.49)
The placebo effect is very much a two edged sword. Don't cut yourself:) .......
388: Tubes Asylum, Re: Seeking advice on budget 5751s (0.00)
Posted by Tom Dawson on 2005-10-03, 07:28:33 (164.54.52.49)
Hi - I just tried a couple of Sylvania JAN5751 from 1974 (two mica)in my homebrew phono pre and liked most of what I heard. However, the midrange forwardness started to bother me after about an hour o .......
389: High Efficiency Speaker Asylum, Re: fave diy speakers to handle drumkit transients? (0.00)
Posted by Tom Dawson on 2005-09-29, 16:51:02 (164.54.52.49)
How's it going? My basement blasters R my fave DIY speakers for really smoking transients, especially when run off the Crown K2. Btw, I once tried something with the Crown and my DC coupled OTL that .......
390: Propeller Head Plaza, Re: All you’ve proven is once the suggestion is planted in your mind... (0.00)
Posted by Tom Dawson on 2005-09-29, 16:04:36 (164.54.52.49)
Could well be - which only goes to show that if the quantum dud can't make any one of them sound significantly better than the other nine pieces 'o crap, it ain't wuth much. .......
391: Propeller Head Plaza, Re: GSIC single blind testing results (0.00)
Posted by Tom Dawson on 2005-09-29, 15:59:44 (164.54.52.49)
Maybe it would be helpful if, once you feel you have established that you consistently hear a definite improvement on a particular treated disc (buy two cheapies, treat one?) that you find a completel .......
392: Vinyl Asylum, Re: I use the cat test (0.00)
Posted by Tom Dawson on 2005-09-29, 13:38:35 (164.54.52.49)
Interesting point. I can play LPs all evening at live levels and barely notice, if at all any negative effect on my short term hearing, but try the same with all CDs or even most high def digital for .......
393: Propeller Head Plaza, No doubt these people can convince themselves these things 'work' with cassettes, LPs, IPODs, FM, dandruff-you name it. (0.00)
Posted by Tom Dawson on 2005-09-27, 09:56:51 (164.54.52.49)
It's a potential gold mine. .......
394: OTL Asylum, Re: not to worry.... (0.00)
Posted by Tom Dawson on 2005-09-27, 09:26:20 (164.54.52.49)
Sure, but this cap is just to bypass the fuse which has the undesirable sonic characteristic and won't compromise the DC ouput coupling at all. .......
395: OTL Asylum, Re: 6DJ8 tube recommendations for Joule OTL? (0.00)
Posted by Tom Dawson on 2005-09-27, 09:20:22 (164.54.52.49)
Thanks for the lead. I'll have to try some 5751s in place of the 12ax7s in my phono preamp. However, I've designed both an OTL and the phono preamp each of which could accept either 6DJ8's or 6BK7's i .......
396: Vinyl Asylum, Re: Vibration sinking VS. vibration isolation (0.00)
Posted by Tom Dawson on 2005-09-27, 08:59:48 (164.54.52.49)
AFAIC, sinking with an approach such as you describe is ultimately preferable, but in my case, I have a full basement while my phono setup is on the second floor plus I generate substantial SPLs close .......
397: Vinyl Asylum, Re: Wall mounting turntables (0.00)
Posted by Tom Dawson on 2005-09-27, 08:13:47 (164.54.52.49)
I'd certainly like to do that, but am afraid that after my cat is done pissing in the dust cover she'll ambush my tonearm. .......
398: Vinyl Asylum, Re: Wall mounting turntables (0.00)
Posted by Tom Dawson on 2005-09-26, 14:58:57 (164.54.52.49)
I seem to be having good luck by putting my LP12 on Isopods with a special bottom panel I made myself from a 1/8" thick sheet of lead sandwiched between 2 1/2" thick sheets of baltic birch plywood. I' .......
399: High Efficiency Speaker Asylum, Re: How important is very high output capability? (0.00)
Posted by Tom Dawson on 2005-09-23, 12:07:12 (164.54.52.49)
Hi, Duke - For several years my main speakers were Chartwell LS3/5a's. However, referencing live music eventually led to dissatisfaction with their headroom, so I went to the opposite extreme:) You an .......
400: OTL Asylum, Re: not to worry.... (0.00)
Posted by Tom Dawson on 2005-09-21, 07:47:53 (164.54.52.49)
I'm not sure of the ESL 57's exact impedance characteristic, but I understand that electrostatic speakers in general are generally capacitive loads at higher frequencies. I wonder if you could retain .......
401: High Efficiency Speaker Asylum, Re: How important is very high output capability? (0.00)
Posted by Tom Dawson on 2005-09-20, 09:57:57 (164.54.52.49)
I'd go for the one which has the higher undistorted peaks because the reduction in distortion will most likely still be perceptible at much lower levels. .......
402: High Efficiency Speaker Asylum, Re: Fostex speakers in 4 ohm or 16 ohm??? (0.00)
Posted by Tom Dawson on 2005-09-13, 13:51:26 (164.54.52.49)
My vote is for 16 ohm. .......
403: Tubes Asylum, How good are NOS GE 6AX7s? (0.00)
Posted by Tom Dawson on 2005-09-07, 13:56:26 (164.54.52.49)
I have about ten of them. They have the largest plate structure I've seen for a nAX7 type tube. They're gray plates and I think they're from the fifties. Are they worth rewiring the socket filament pi .......
404: Tubes Asylum, Re: DIY Cryo for tubes? (0.00)
Posted by Tom Dawson on 2005-09-06, 14:36:37 (164.54.56.3)
Any process that intrinsically tends to reduce tube microphonics would seem to be a good thing. Wonder what his going rate is. Might be worth having him cryo a grab bag 'o parts & tubes if not too exp .......
405: Water Cooler, So, how were the Strolling Bones? (0.00)
Posted by Tom Dawson on 2005-08-29, 14:33:08 (164.54.56.3)
Not as tired as LW rhetoric, I imagine. .......
406: High Efficiency Speaker Asylum, Re: wish me well (0.00)
Posted by Tom Dawson on 2005-08-29, 13:52:38 (164.54.56.3)
Best wishes and good luck. May you live to be a centenarian. .......
407: High Efficiency Speaker Asylum, Re: Is there any real fullrange speaker with out beaming??? (0.00)
Posted by Tom Dawson on 2005-08-24, 12:45:38 (164.54.56.3)
How about four good quality 3 -4" drivers mounted in a tight rectangular pattern but splayed out 15 or so degrees to widen HF dispersion? .......
408: OTL Asylum, Re: cascode current (0.00)
Posted by Tom Dawson on 2005-08-18, 15:31:50 (164.54.56.3)
Hi - Don't know how much gain you're currently getting from the 12at7 part of the cascode stage, but wonder if maybe a 12av7 would buy you anything. Wouldn't have to rewire the filament, at least. ::: .......
409: Shady Lane, Paypal part of the problem? (0.00)
Posted by Tom Dawson on 2005-08-10, 09:26:31 (164.54.56.3)
I had a Paypal account which I had never used, and recently a lot of this happened to me when I tried to access my Paypal account. I responded by demanding that Paypal cancel my account which they hav .......
410: High Efficiency Speaker Asylum, Re: Air Core vs. Iron core(EI) inductors... (0.00)
Posted by Tom Dawson on 2005-08-10, 07:08:12 (164.54.56.3)
air cores don't saturate..... .......
411: High Efficiency Speaker Asylum, Re: cheapest sub possible (0.00)
Posted by Tom Dawson on 2005-08-05, 16:41:24 (164.54.56.3)
How about this? Get two 15" diameter 6 foot sonotubes, cut away to make footies at their bottoms & hot glue cheap 15" woofers at their tops & bottoms. .......
412: Tape Trail, Re: Something to consider... (0.00)
Posted by Tom Dawson on 2005-08-03, 11:48:03 (164.54.56.3)
Hi, Dave - You raise good points. The lowered impedance and required drive level for the cassette record heads may actually match the tube electronics well enough if the drive current required is not .......
413: High Efficiency Speaker Asylum, Re: yet another debate, analogue vs digital xovers/eq's (0.00)
Posted by Tom Dawson on 2005-08-03, 08:46:43 (164.54.56.3)
Wow! Good responses, IMO. Of course, I'm partial to my quasi first order passive approach. .......
414: Tape Trail, Re: Technics RS-9900US (0.00)
Posted by Tom Dawson on 2005-07-26, 14:08:50 (164.54.56.3)
Hey, thanks, Bobbo! The Technics RS-9900US looks like it would be the ideal starting point what with its electronics/transport chassis segregation, meaning that it might be possible to do what I'm thi .......
415: Tape Trail, Looking for high quality cassette recorder/transport to work with Ampex 354 electronics (0.00)
Posted by Tom Dawson on 2005-07-26, 10:00:55 (164.54.56.3)
I've got the 354 electronics laying around and thought with appropriate eq mods & a cap upgrade that it might make a very good set of high quality vacuum tube electronics for the right 3 head cassette .......
416: Propeller Head Plaza, Re: Physiological and pshychological aspects of MP3 listening (0.00)
Posted by Tom Dawson on 2005-07-19, 23:35:41 (4.159.237.61)
Good for you, re. using the Apple lossless algorithm. OTOH, if rigorously defined, many requantizations, even if just to a non-multiple clock rate, involve some small loss of analog information. IMO, .......
417: Propeller Head Plaza, Re: Looks like 80 dB to me... (0.00)
Posted by Tom Dawson on 2005-07-16, 21:29:59 (4.159.237.169)
Hi - Can you provide a little more information about which 24 bit A/D you used? TIA .......
418: Propeller Head Plaza, Re: 150 db? (0.00)
Posted by Tom Dawson on 2005-07-14, 16:27:07 (164.54.56.3)
Dunno about the applicability of such a generic statement that claims that total distortion is less than -150 db without qualifying measurement parameters, but I once prototyped a log/antilog amplifie .......
419: High Efficiency Speaker Asylum, Re: Boy, do hear that! (0.00)
Posted by Tom Dawson on 2005-07-14, 09:13:29 (164.54.56.3)
Ferrite being a relative insulator compared to alnico or neodymium 'shorting rings' are necessary to keep the appellation 'mud magnet' from also implying relatively muddy sound due to flux modulation .......
420: High Efficiency Speaker Asylum, Re: 300B SET & Ferrite (0.00)
Posted by Tom Dawson on 2005-07-14, 08:58:59 (164.54.56.3)
I have nothing much against a properly designed ferrite magnet structure (i.e. that includes some design feature to neutralize distortion causing flux modulation). I'm listening to such a driver, a JB .......
421: High Efficiency Speaker Asylum, Re: 300B SET & ALTEC A7 (0.00)
Posted by Tom Dawson on 2005-07-13, 16:17:56 (164.54.56.3)
With only 8 watts driving, I don't think you need be concerned about incurring alnico magnetism loss (which is almost entirely due to overpowering or mechanical shock as from dropping). Whatever you b .......
422: High Efficiency Speaker Asylum, Re: Solid soundboard for enclosures? (0.00)
Posted by Tom Dawson on 2005-07-13, 08:34:33 (164.54.56.3)
If it makes a Yamaha upright sound like a Bosendorfer, what will it make a Stradivarius sound like? :) (paraphrasing djk's response here) Any overt coloration that is designed into a component deliber .......
423: High Efficiency Speaker Asylum, Re: will a 60 x 40 horn be too harsh for hi-fi use (0.00)
Posted by Tom Dawson on 2005-07-13, 08:28:05 (164.54.56.3)
I don't think it should be a problem for your application if there are other reasons you need the slightly narrower lateral pattern control. It may be that CD horns in general exhibit a slightly more .......
424: Speaker Asylum, Re: If First Order Crossovers are "Better" , Why Arent They Used More ? (0.00)
Posted by Tom Dawson on 2005-07-13, 07:51:49 (164.54.56.3)
First order xovers offer the potential for greatly superior waterfall responses compared to higher order minimum phase speaker xovers. That being said, xover overlap can be first order's largest limit .......
425: High Efficiency Speaker Asylum, Re: Boy, do hear that! (0.00)
Posted by Tom Dawson on 2005-07-13, 07:19:33 (164.54.56.3)
Alnico is about 30 times more stable with temperature than mud magnets, and has far less distortion than 95% of mud magnet implementations on top of that, as someone else has pointed out. OTOH, if you .......
426: OTL Asylum, Re: 1000 Ohm loudspeaker (0.00)
Posted by Tom Dawson on 2005-07-12, 15:09:50 (164.54.56.3)
Sure, a 1000 ohm voice coil driver can be made, but it would probably require special production techniques with conventional materials. And you probably won't have much of a market for it. To achieve .......
427: Propeller Head Plaza, Re: there can be no end to bias accusations (0.00)
Posted by Tom Dawson on 2005-07-12, 14:34:36 (164.54.56.3)
Get someone to act like a GSIC true believer and either get to an actual true believer's place & 'treat' some CDs with an 'expired' GSIC or bring some already treated CDs to be treated with either 'go .......
428: Propeller Head Plaza, Easy to be Difficult or GSIC Leakage (0.00)
Posted by Tom Dawson on 2005-07-12, 08:03:52 (164.54.56.3)
If you store GSIC chips between 2 feet and 500 feet from any operating optical disc drive, especially if there is more than one and any are not being used, the GSIC whatchamagiktrons only get confused .......
429: High Efficiency Speaker Asylum, Re: cement (0.00)
Posted by Tom Dawson on 2005-07-12, 07:35:31 (164.54.56.3)
If you cast with fiber reinforced concrete, cracking shouldn't be much of a problem - it wasn't for the concrete mid horns I cast which have developed no cracks. Another thing you can do with concrete .......
430: Propeller Head Plaza, Re: How can XRCD work? (0.00)
Posted by Tom Dawson on 2005-07-07, 08:51:43 (164.54.56.3)
Perhaps JVC means that they lose less 'warmth' in the original recording with their process more than anything else. The very best 16 bit PCM I've heard is 'ok' (not great, but not way off) sounding i .......
431: Propeller Head Plaza, Re: How can XRCD work? (0.00)
Posted by Tom Dawson on 2005-07-05, 08:28:43 (164.54.56.3)
I'm sure I don't have the whole story, but it's quite possible to add jitter to the mastered signal by unnecessary or suboptimal requantization, which is one thing JVC seems to be attempting to avoid. .......
432: Shady Lane, Re: Bose lifestyle systems on Ebay (0.00)
Posted by Tom Dawson on 2005-07-01, 12:19:43 (164.54.56.3)
I hope it's not your parent's 2K + grand that's being forked out for these Bose underperformers. They constitute a scam in their own right. .......
433: High Efficiency Speaker Asylum, Re: JBL D130...why did this speaker sell for so much?? Rare model? (0.00)
Posted by Tom Dawson on 2005-07-01, 09:22:48 (164.54.56.3)
Hi, djk- How much, in your experience did later versions of the the D130 lose wrt its midband efficiency (before cone breakup) as compared to the highest efficiency earlier versions? JBL's new online .......
434: OTL Asylum, Re: My SET amps are (0.00)
Posted by Tom Dawson on 2005-07-01, 07:58:40 (164.54.56.3)
I was afraid someone would post something like that. I've seen this ascribed to the idea that the multiple pairs of OTL output devices have a negative effect on the overall transparency relative to a .......
435: OTL Asylum, Re: Curious why the O.T.L. board moves so much slower than the S.E.T. board. (0.00)
Posted by Tom Dawson on 2005-06-29, 08:19:38 (164.54.56.3)
I suppose I ought to make a try at marketing this OTL topology, but I somehow have never got around to it - too many competing projects and things to do, I suppose, and I've been more of a lab rat bei .......
436: OTL Asylum, Re: Curious why the O.T.L. board moves so much slower than the S.E.T. board. (0.00)
Posted by Tom Dawson on 2005-06-28, 12:36:42 (164.54.56.3)
My topology for a DC coupled OTL differs substantially from both the Futterman's and Circlotron's and it seems plenty viable to me, having given trouble free day-to-day use for seventeen years now. Ho .......
437: Tube DIY Asylum, Anyone have an unneeded pair of 3 1/8" mounting center x-style xfmrs with end bells? (0.00)
Posted by Tom Dawson on 2005-06-27, 16:34:24 (164.54.56.3)
I need the end bells for a pair of this style & size of transformer to add to my homebrew phono preamp, or such transformers with approx 325VAC secondaries. Ever since I built this preamp it's had a l .......
438: High Efficiency Speaker Asylum, Re: Crumpled surround on Tannoy Monitor Gold...what the heck? Need help/advice.... (0.00)
Posted by Tom Dawson on 2005-06-24, 22:13:14 (4.158.126.49)
Cosmetics rate only a 5 out of 10 here:), but given the small percentage of the overall surround affected, and that it's really not that severe, it should have negligible effect on sonic performance. .......
439: Propeller Head Plaza, As per Langmuir's 'Pathological Science', the GSIC has begun its trip down the slippery slope to oblivion nt (0.00)
Posted by Tom Dawson on 2005-06-24, 21:51:17 (4.158.126.49)
:) .......
440: Propeller Head Plaza, Re: As the someone... (0.00)
Posted by Tom Dawson on 2005-06-21, 16:56:42 (164.54.56.3)
What bothers me about the hucksterism behind this thing goes well beyond the mere fact that perfectly good science is being perverted into a new alchemy to sell worthless chunks of what appear to be c .......
441: Propeller Head Plaza, Re: Why bother what? [nt] (0.00)
Posted by Tom Dawson on 2005-06-21, 16:46:01 (164.54.56.3)
If you were for real, you'd be clamoring for such a test to be performed. After all, the verifiable claim has been officially made by purportedly 'responsible' individuals. .......
442: Propeller Head Plaza, Re: Ah, reality... (0.00)
Posted by Tom Dawson on 2005-06-21, 16:33:16 (164.54.56.3)
How do you know you haven't already been gulled by somebody who asked you to listen to the 'effects' of one of these things that he had already 'depleted' without informing you about it. Uh oh. ::: TO .......
443: Propeller Head Plaza, Geoffkait begs to differ, I'm sure. (0.00)
Posted by Tom Dawson on 2005-06-21, 08:21:14 (164.54.56.3)
I'll just kick back with some popcorn and wait for the fun to begin. .......
444: Propeller Head Plaza, Re: good points... (0.00)
Posted by Tom Dawson on 2005-06-20, 00:43:28 (4.159.233.43)
but your inferences are not what I was implying. I was simply referring to that if the chip does make a difference (that is people like and hear what it does), does their explanation really matter? O .......
445: Propeller Head Plaza, Since no incontrovertible test will ever show that the 'GSIC' improves CD optical transparency as claimed, why bother? (0.00)
Posted by Tom Dawson on 2005-06-20, 00:23:20 (4.159.233.43)
All attempts to promote the GSIC are either flimflammery or result from self deception. .......
446: High Efficiency Speaker Asylum, Re: time aligning in coaxials (0.00)
Posted by Tom Dawson on 2005-06-17, 16:11:08 (164.54.56.3)
I don't see any particular problem if the HF acoustical center is a couple of inches behind that of the woofer. That can be compensated for in the xover, usually without adding any components, or if n .......
447: OTL Asylum, Re: Berning ZH270 or Seigfried compared to Atma-sphere MA60 (0.00)
Posted by Tom Dawson on 2005-06-17, 10:07:40 (164.54.56.3)
I don't mean to cast aspersions on David Berning's ingenious circuit or to deny his basic claims for its capabilities, which in my estimation, include removing the typical tube amplifier output transf .......
448: High Efficiency Speaker Asylum, Re: Something Different (0.00)
Posted by Tom Dawson on 2005-06-15, 23:13:24 (4.131.15.195)
Would a plate Subwoofer amp mounted right in the box be *too* cheap & nasty? It could be driven right off the 18" input terminals & may already have handy LP filter built in. .......
449: OTL Asylum, Re: Berning ZH270 or Seigfried compared to Atma-sphere MA60 (0.00)
Posted by Tom Dawson on 2005-06-15, 22:45:10 (4.131.15.195)
The tubes see the speaker characteristics and vise versa, no transformer made can allow that to happen if it's in the signal path! Unfortunately, perhaps, his patent application for this idea describ .......
450: OTL Asylum, Re: Berning ZH270 or Seigfried compared to Atma-sphere MA60 (0.00)
Posted by Tom Dawson on 2005-06-12, 23:18:23 (4.158.93.6)
Well, this is how DB apparently described its operation at one point: The ZOTL falls into a generic class of amplifier described by the acronym OTL both technically and in spirit. The power conversion .......
451: High Efficiency Speaker Asylum, Re: When is a loudspeaker high efficiency? (0.00)
Posted by Tom Dawson on 2005-06-08, 21:58:15 (4.158.51.129)
I'm personally on board with the 100db/w/m actual efficiency criterion, although eso makes a cogent point wrt the efficiency of high quality full range reproducers. 105db/w/m is just perhaps a bit too .......
452: High Efficiency Speaker Asylum, Re: Tad 4001/Suprovox 400 field coil project help (0.00)
Posted by Tom Dawson on 2005-06-08, 08:25:47 (164.54.56.3)
This approach has the significant merit, IMO, of not adding any active devices to the signal chain. On a slightly related note, I once designed an 'almost passive' parametric low/mid frequency notch f .......
453: High Efficiency Speaker Asylum, Re: this is interesting (0.00)
Posted by Tom Dawson on 2005-06-08, 07:32:33 (164.54.56.3)
Hi, djk - Do you know of any online information regarding them? A google search mostly turned up some info on a Behringer stomp box:) I've found, as you mentioned, that the driver offset is important .......
454: High Efficiency Speaker Asylum, Re: ot - transparency of chain (0.00)
Posted by Tom Dawson on 2005-06-07, 07:31:21 (164.54.56.3)
Those are some some wide ranging questions, and I don't have complete answers. But, to ruin a recording, passing it through a low resolution digital format would be a good start. For myself, it's more .......
455: High Efficiency Speaker Asylum, Re: this is interesting (0.00)
Posted by Tom Dawson on 2005-06-06, 13:52:11 (164.54.56.3)
Hi, Chiggy - Actually, freddyi listed some results he measured when using this approach with a first order xover at about 1500hz, where he added such a notch filter at about 300hz. He was able to, wit .......
456: High Efficiency Speaker Asylum, Re: "Major technical flaw".... (0.00)
Posted by Tom Dawson on 2005-06-04, 21:52:41 (4.158.126.233)
The excursion requirements at even 3600 hz are relatively modest for any reasonable home listening level. However, if you are concerned about any excess distortion that caused by out of band excursion .......
457: High Efficiency Speaker Asylum, Re: please explain... (0.00)
Posted by Tom Dawson on 2005-06-04, 20:53:35 (4.158.126.233)
True. That's why I use modified first order xovers in my designs having out of band shunt notches that, together with the series component will provide minimum stopband rejection of a specific value, .......
458: High Efficiency Speaker Asylum, Re: Altec 806A - First Order Crossover - - 1K5 values? - higher order highpass? notch width? (0.00)
Posted by Tom Dawson on 2005-06-01, 08:02:32 (164.54.56.3)
Hi, Freddy - Looks like you should be able to get 4-6 db no problem around 50 hz - try target Z for L&C of 8 ohms at that frequency, & make sure electrolytic low enough ESR & high enough voltage not t .......
459: High Efficiency Speaker Asylum, Re: Altec 806A - First Order Crossover - - 1K5 values? - higher order highpass? notch width? (0.00)
Posted by Tom Dawson on 2005-05-29, 22:09:42 (4.159.229.248)
Unless the 20 hz is well over a thousand watts in power, I don't see a problem for the HF driver with the notch approach alone. You can put a second order network in front, but there will be some inte .......
460: High Efficiency Speaker Asylum, Re: Altec 806A - First Order Crossover - - 1K5 values? - higher order highpass? notch width? (0.00)
Posted by Tom Dawson on 2005-05-28, 21:01:25 (4.158.39.231)
in practise - what factors really stress & fry most compression drivers? - (currently running transform on 2-way - all run from one amp) Well, here's my general set of assumptions, and I'm not nearly .......
461: High Efficiency Speaker Asylum, Re: Altec 806A - First Order Crossover - - 1K5 values? - higher order highpass? notch width? (0.00)
Posted by Tom Dawson on 2005-05-28, 16:18:38 (164.54.56.3)
Hi, Freddy - Looking at those figures, it might be worth moving the notch a little lower in frequency - say to around 300 hz and broadening it a bit - could try 100 - 150 uF. That should get you sign .......
462: High Efficiency Speaker Asylum, Re: Altec 806A - First Order Crossover - - 1K5 values? (0.00)
Posted by Tom Dawson on 2005-05-26, 11:54:52 (164.54.56.3)
Hi, Don - Any deficiencies lower cost notch filter parts have as components (e.g. 'lytic capacitors or ferrite core chokes) will cause a much smaller audible effect than if they were directly in the s .......
463: High Efficiency Speaker Asylum, Re: Altec 806A - First Order Crossover - - 1K5 values? (0.00)
Posted by Tom Dawson on 2005-05-25, 12:42:22 (164.54.56.3)
Hi, Freddy - good to hear from you - The series capacitor value depends on how much resistor padding you use, but just assuming 8 ohms, you can start with say 6.2 uF. If we put the notch at 400 hz, y .......
464: Propeller Head Plaza, Somehow, actual measurements of the effect on CD transparency are omitted. (0.00)
Posted by Tom Dawson on 2005-05-24, 22:51:42 (4.158.51.2)
There's an 'Intelligent Chip' buyer born every minute is the hope here, apparently. .......
465: High Efficiency Speaker Asylum, Re: Altec 806A - First Order Crossover (0.00)
Posted by Tom Dawson on 2005-05-23, 15:47:25 (164.54.56.3)
Why not go first order with out of band notches (particularly for the horn)? That should get you stopband rejection effectively as good as or better than second order, yet while keeping near first ord .......
466: Propeller Head Plaza, Re: HANG ON EVERYONE! Lets try again without so much bickering (0.00)
Posted by Tom Dawson on 2005-05-20, 14:43:54 (164.54.56.3)
*Anything* played through a Bose Wave or average boombox will be a spatially undifferentiated bolus of not very clean sound. While jitter can theoretically have the characteristics of anything from ra .......
467: Vinyl Asylum, Re: Feel free to throw them in my direction. Need an address? /nt\ (0.00)
Posted by Tom Dawson on 2005-05-18, 13:32:15 (164.54.56.3)
Exactly what I was going to post when I first noticed this thread (a second ago). I figure when you get to a certain level of playback quality (and have reasonable pressing quality), the limiting fact .......
468: Vinyl Asylum, More LP12 dust cover experiments (0.00)
Posted by Tom Dawson on 2005-05-18, 08:07:45 (164.54.56.3)
Last night, I tried the next step in modifying the dust cover by basically attaching a foam strip all around the base upon which the dust cover sits. Now, when the weight is applied to the dust cover, .......
469: High Efficiency Speaker Asylum, Re: MDF horns and table saw! Amen! (0.00)
Posted by Tom Dawson on 2005-05-18, 07:52:57 (164.54.56.3)
In my cheapness, I've foregone the table saw in favor of a hand held circular saw or reciprocating saw and touch up cuts for accuracy with a router or by sanding. I figure they're slightly less danger .......
470: Propeller Head Plaza, Re: Interesting... (0.00)
Posted by Tom Dawson on 2005-05-17, 14:23:52 (164.54.56.3)
Gosh, it's been a while, and the urls that used to discuss some of these things may be gone. However, I recall an analysis of the variable distortions of the pits in commercial Redbook CDs which had a .......
471: Propeller Head Plaza, The fact that they usually don't highlights the importance of.... (0.00)
Posted by Tom Dawson on 2005-05-17, 13:52:17 (164.54.56.3)
..the differences between a statically pressed versus a dynamically laser burned disc, the differences in reflectivity and refractivity between the various materials of the different discs, and any di .......
472: Propeller Head Plaza, I can refurbish Intelligent Chips to work like new for a moderate fee. (0.00)
Posted by Tom Dawson on 2005-05-14, 01:13:39 (67.248.80.229)
If anyone is interested, let me know. .......
473: DVD-Audiobahn, Re: For those of you that dislike Dolby Digital for music, i've done an interesting experiment ... (0.00)
Posted by Tom Dawson on 2005-05-11, 07:16:52 (164.54.56.3)
With DD, 'substandard' AQ is the norm, and given the computation needed to do an 'optimal' decoding job, it will stay that way for the indefinite future. What is needed is the general adoption of an a .......
474: General Asylum, My error (0.00)
Posted by Tom Dawson on 2005-05-07, 22:42:11 (67.248.80.203)
It seems the Vinyl Asylum breaks their threads up into more than one page, and my posting eventually wound up on 'page 2' which I didn't know the existence of. My apologies for jumping the gun on this .......
475: Vinyl Asylum, oops (0.00)
Posted by Tom Dawson on 2005-05-07, 22:40:06 (67.248.80.203)
There they are, on page 2. My apologies for not considering this possibility. Moderators - feel free to remove my posts here:) .......
476: Vinyl Asylum, Re: Why have my posts in this forum been deleted? (0.00)
Posted by Tom Dawson on 2005-05-07, 22:06:33 (67.248.80.203)
One was a response to a question as to how to fix a too-small center hole on a LP (I suggested using a round file) and the rest were regarding my experiences with controlling vibrations through a dust .......
477: Vinyl Asylum, Why have my posts in this forum been deleted? (0.00)
Posted by Tom Dawson on 2005-05-07, 21:46:08 (67.248.80.203)
I haven't broken any of the rules and have been on topic, so I think I am owed an explanation here. .......
478: General Asylum, Why have my posts in theVinyl forum been deleted? (0.00)
Posted by Tom Dawson on 2005-05-07, 21:42:45 (67.248.80.203)
I haven't broken any of the rules and have been on topic, so I think I am owed an explanation here. I have posted this question here as well as the Vinyl Forum just in case that post also gets taken o .......
479: Vinyl Asylum, Re: Dust Cover experiments (0.00)
Posted by Tom Dawson on 2005-05-05, 14:23:12 (164.54.56.3)
Hi, John - Recording LPs to reel to reel tape is something I've done in the past and would do now for the reason you suggest, but I've got myself into an impasse with tape since I hacked up my Ampex 3 .......
480: High Efficiency Speaker Asylum, Re: 15 coax - "she's too fat for me?" - when is high mms desirable in wideband? (0.00)
Posted by Tom Dawson on 2005-05-05, 12:44:49 (164.54.56.3)
I've always suspected that one reason that light cone, high compliance, low qts 15s tend to sound better is that they have less of a mechanical impedance mismatch with air and thus their various reson .......
481: Vinyl Asylum, Re: Dust Cover experiments (0.00)
Posted by Tom Dawson on 2005-05-05, 08:11:44 (164.54.56.3)
You wouldn't have that dust cover available for sale by any chance, would you? Just in case my potentially messy modification fails, that is. .......
482: Vinyl Asylum, Re: Cats think LP-12's are toys! nt (0.00)
Posted by Tom Dawson on 2005-05-05, 08:10:16 (164.54.56.3)
Exactly. 'Scratchy' the Cat likes to sit or stand on the dust cover on occasion. .......
483: Vinyl Asylum, Dust Cover experiments (0.00)
Posted by Tom Dawson on 2005-05-04, 16:01:40 (164.54.56.3)
I have an old Linn Sondek LP12 with a Grace G-707 tone arm and a Shure V15 type 5 MR cartridge - all original from around 1980 (except the stylus) and it still works fine. I've done a few mods to the .......
484: Vinyl Asylum, Re: Help with small spindle hole (0.00)
Posted by Tom Dawson on 2005-05-04, 15:20:56 (164.54.56.3)
I first determine if there is any eccentricity that can be corrected, then use a small round file to hog out the hole by hand, making sure any shavings are removed from the record before playing. Try .......
485: High Efficiency Speaker Asylum, Re: Thanks ya'll... (0.00)
Posted by Tom Dawson on 2005-04-29, 12:13:50 (164.54.56.3)
How do you plan to keep them tensioned over time? .......
486: Propeller Head Plaza, Re: Isn't it obvious? (0.00)
Posted by Tom Dawson on 2005-04-22, 20:50:49 (67.248.68.21)
"There is no guarantee it will work in your system. You pays your money and you takes your chances." Two words: placebo effect .......
487: High Efficiency Speaker Asylum, Re: I've got tubby, bloated bass Is there hope for me? (0.00)
Posted by Tom Dawson on 2005-04-22, 20:45:46 (67.248.68.21)
If your bass emphasis problems are limited to a relatively narrow range of frequencies per speaker, you may be able to resolve them by adding Helmholtz resonators tuned to the problem frequency(ies) n .......
488: High Efficiency Speaker Asylum, Re: Selenium ST350 Sortatweeters (0.00)
Posted by Tom Dawson on 2005-04-22, 07:44:19 (164.54.56.3)
I think that dispersion is supposed to be the grabber. .......
489: High Efficiency Speaker Asylum, Re: Test with URL (0.00)
Posted by Tom Dawson on 2005-04-21, 15:09:39 (164.54.56.3)
Thanks for the informative link. However, I don't really read German so I can't tell for sure if the article specifies how each speaker was located in the room when the measurements were taken. The K .......
490: Propeller Head Plaza, Re: Paul Klipsch's BS- buttons (0.00)
Posted by Tom Dawson on 2005-04-20, 07:34:53 (164.54.56.3)
How's this? I'll need something different because all this QD foofaraw damaged my bsometer. .......
491: Propeller Head Plaza, Re: Upsampling software (0.00)
Posted by Tom Dawson on 2005-04-19, 21:04:19 (67.248.80.177)
You're correct regarding SACD's limitations & wrt that, some have described some equipment as being 'SACD Friendly or unfriendly', depending on how much SACD's ultrasonic component excites their nonli .......
492: Propeller Head Plaza, Re: Intelligent Chimp questions (0.00)
Posted by Tom Dawson on 2005-04-19, 14:03:46 (164.54.56.3)
I just noticed this on my bsometer while reading about this 'chip': .......
493: Propeller Head Plaza, Re: Upsampling software (0.00)
Posted by Tom Dawson on 2005-04-19, 13:49:53 (164.54.56.3)
I'm glad you're pleased with Redbook - I never was and its best still falls dismally short of SACD, DVDA and good old analog, both on paper, and in the listening room, in my experience. Possibly the m .......
494: Propeller Head Plaza, Re: Upsampling software (0.00)
Posted by Tom Dawson on 2005-04-18, 01:35:38 (67.248.80.170)
Sounds like you're doing some very interesting work. However, I differ with the following assertion: "Also, this stuff is leading me to believe that 16/44.1 may not be good enough for recording or pla .......
495: High Efficiency Speaker Asylum, Re: I have used them (0.00)
Posted by Tom Dawson on 2005-04-11, 09:10:14 (164.54.56.3)
Fostex claims a 'PPTA' dielectric for them which is another name for Kevlar which has a k of 3.9, plus a 1khz dissipation rating of better than 2.5%. Hmmmm. .......
496: High Efficiency Speaker Asylum, Re: "Flexible" box ideas needed for different drivers; Karlson K-15? (0.00)
Posted by Tom Dawson on 2005-04-07, 13:51:38 (164.54.56.3)
The following ideas assume that this box is for testing ideas and drivers more than anything else. You could cut the mounting hole for your 15's and make adaptor rings for smaller diameter drivers. Yo .......
497: High Efficiency Speaker Asylum, thanks for the information (0.00)
Posted by Tom Dawson on 2005-04-07, 13:30:14 (164.54.56.3)
Sounds like the aniline dyes are probably the ticket here. I'll have to order some shades and do a few tests - maybe go for a rosewood or mahogany hue. Btw, I've had success before refinishing the top .......
498: High Efficiency Speaker Asylum, Re: Low-volume fidelity (0.00)
Posted by Tom Dawson on 2005-04-07, 08:36:32 (164.54.56.3)
It just occurred to me that a tallish speaker having more than one bass driver but a point source HF unit (like, say my basement blasters) would have a certain amount of 'loudness compensation' built .......
499: High Efficiency Speaker Asylum, Any way to stain baltic birch plywood dark without... (0.00)
Posted by Tom Dawson on 2005-04-07, 08:07:46 (164.54.56.3)
...having to slather the stuff on to the point where the effect is artificial? I'm looking for a moderate to dark effect for my next design and I'm ok with simply emphasizing the natural plywood style .......
500: High Efficiency Speaker Asylum, Re: (2) K-140+Isobaric=deep bass?? (0.00)
Posted by Tom Dawson on 2005-04-07, 07:35:12 (164.54.56.3)
Wonder how reliable any correlation to the E140 Xmax rating is here. Would the difference in measurement procedures account for the boost to 3.56mm, and would something similar be the cause of the inc .......
Found total of 500 records, Query: , Author: Tom Dawson in All Forums, Time: 1 sec.