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1: Speaker Asylum, Midwest Audio Fest Speaker Design Competition (0.00)
Posted by Duke on 2021-07-16, 19:58:25 (67.210.155.86)
The competition categories' dividing line is not necessarily at $500 retail in parts, but this sort of competition has been done for years, with the winners often being offered as a kit by somebody. M .......
2: High Efficiency Speaker Asylum, RE: And other than that, how be you, Duke? (0.00)
Posted by Duke on 2021-07-15, 20:24:53 (67.210.155.86)
Great photo - my wife graduated from that high school. Tater tots are a real thing there. And Vote for Pedro shirts were even a thing in tourist shops in the French Quarter back in New Orleans. I'm i .......
3: High Efficiency Speaker Asylum, RE: That plus the 15in cone is 106dB at best when horn loaded (0.00)
Posted by Duke on 2021-07-15, 11:08:47 (67.210.155.86)
"... the 15in cone is 106dB at best when horn loaded while the 2441 111dB when horn loaded, and if the cone driver in the mid-bass is 8 Ohms it all makes sense." Yes it does! And all of a sudden it do .......
4: High Efficiency Speaker Asylum, RE: I suspect it was just another method of... (0.00)
Posted by Duke on 2021-07-14, 21:19:16 (67.210.155.86)
Forty microfarads into the ballpark 8 ohm load = about 500 Hz first-order highpass filter on the midrange horn. Presumably that was enough protection for home audio, as I haven't heard of any related .......
5: Planar Speaker Asylum, Excellent. (0.00)
Posted by Duke on 2021-07-09, 17:41:01 (67.210.155.86)
The 90-degree pattern versions have very wide coverage, and because they behave as a line source the far speaker's SPL only falls off by half as much as with conventional speakers, so you can still he .......
6: Speaker Asylum, RE: On the same page?? (0.00)
Posted by Duke on 2021-07-05, 21:17:52 (67.210.155.86)
I didn't think you were referring to any of my stuff in your second comment there - sorry if I gave that impression! Yeah the Azel Tower is pretty big. I'm working on smaller incarnations of the same .......
7: Speaker Asylum, On the same page?? (0.00)
Posted by Duke on 2021-07-02, 17:26:36 (67.210.155.86)
Rivervalley817, I'm kinda surprised by how much you and I seem to be on the same page. Must be a glitch in the Matrix. "an omni directional / di-pole approach really does impart a more realistic list .......
8: Speaker Asylum, Amar (0.00)
Posted by Duke on 2021-07-02, 07:35:29 (67.210.155.86)
For the amount of time delay the relatively short path lengths in our home audio listening rooms provide, the Bose 901 had WAY too much reverberant energy, relative to the direct sound, in my opinion. .......
9: Speaker Asylum, If what you seek to accomplish is... (0.00)
Posted by Duke on 2021-07-01, 21:24:12 (67.210.155.86)
... good clean first-arrival sound followed by spectrally-correct reflections, neither too weak nor too strong, arriving from all around... THEN I have been working on essentially THAT for a number of .......
10: High Efficiency Speaker Asylum, Very interesting! (0.00)
Posted by Duke on 2021-01-26, 09:46:28 (67.210.155.86)
That 14-foot(!) path length is arguably a highly worthwhile advantage in this application, with the sub nearfield (right behind your listening position) where its relatively loud direct sound presumab .......
11: High Efficiency Speaker Asylum, It depends... (0.00)
Posted by Duke on 2021-01-26, 01:25:47 (67.210.155.86)
If the subwoofer is further away from you than the main speakers are by at least a foot or so, and preferably in the general vicinity of the main speakers, then you can get away with a higher lowpass .......
12: High Efficiency Speaker Asylum, Rest in peace, Bruce. (0.00)
Posted by Duke on 2021-01-18, 21:43:04 (67.210.155.86)
And thank you for your great speakers and contagious enthusiasm. Duke .......
13: Speaker Asylum, Controlled-pattern speakers, cross-firing (0.00)
Posted by Duke on 2021-01-16, 23:50:49 (67.210.155.86)
The ear localizes sound by two mechanisms: Arrival Time, and Intensity. With conventional speakers set up normally (some toe-in), for a listener along the centerline, Arrival Time and Intensity are t .......
14: Speaker Asylum, Horn sub? Bill Fitzmaurice! (0.00)
Posted by Duke on 2021-01-16, 23:19:47 (67.210.155.86)
Link below. Duke .......
15: Speaker Asylum, "I have the specs for the driver if needed" (0.00)
Posted by Duke on 2020-12-24, 21:01:19 (67.210.155.86)
It you could post the driver's T/S parameters, that would be helpful. Duke .......
16: Speaker Asylum, RE: Multiple woofers in a cabinet (0.00)
Posted by Duke on 2020-12-07, 17:35:24 (67.210.155.86)
When you added a second woofer to your cabinet, your -3 dB point may have gone up by about 1/3 of an octave (the exact amount depends on several specific details), and your efficiency (broadband SPL f .......
17: Speaker Asylum, RE: Would Someone Be Willing (0.00)
Posted by Duke on 2020-12-01, 20:13:07 (67.210.155.86)
In a 27 liter box, you could try tuning to somewhere in the 45-50 Hz ballpark. A 2" diameter port, 2" long, gives a calculated tuning frequency of 48 Hz. The calculated -3 dB point looks like about 53 .......
18: Speaker Asylum, Yup! (0.00)
Posted by Duke on 2020-11-27, 23:04:34 (67.210.155.86)
"The earlier a reflection arrives the more it contributes to masking the direct sound." - Dr. David Griesinger Duke .......
19: Speaker Asylum, RE: Anyone recall how Amar Bose and his M.I.T. team calculated 89% of concert hall sound is reflected? (0.00)
Posted by Duke on 2020-11-27, 22:55:37 (67.210.155.86)
The Bose 901's front-firing driver ALSO contributed reflected sound, so even IF his "89%" figure was a worthy goal for a home audio speaker, imo his execution fell short. That 89% figure was I'm sure .......
20: Speaker Asylum, The elephant in the room... (0.00)
Posted by Duke on 2020-11-03, 16:01:14 (67.210.155.86)
... IS the room. Room interaction inevitably imposes a nasty peak-and-dip pattern on the output of any subwoofer. You can change the pattern by moving the sub and/or moving your listening position, bu .......
21: High Efficiency Speaker Asylum, RE: Which are the most efficient speakers? (0.00)
Posted by Duke on 2020-09-04, 12:02:04 (67.210.155.86)
"Technically, efficiency is sound power output divided by electrical power input. Sound power (in watts) is measured either by integrating over a surface enclosing the source in an anechoic chamber or .......
22: Speaker Asylum, RE: What Jon said. -- Perhaps We Understand 'Distortion' Differently . . . (0.00)
Posted by Duke on 2020-08-30, 18:26:39 (67.210.155.86)
Thanks for your reply; I hope I didn't come across as confrontational. My understanding of "distortion" is that it implies the generation of a new signal which was not actually part of the original (s .......
23: Speaker Asylum, RE: What Jon said. -- Perhaps We Understand 'Distortion' Differently . . . (0.00)
Posted by Duke on 2020-08-30, 15:42:41 (67.210.155.86)
"I view departure from flat frequency response as a "distortion"" I understand what you are saying, but critical distinctions can be obscured by broad-stroke application of the word. For instance some .......
24: Speaker Asylum, What Jon said. (0.00)
Posted by Duke on 2020-08-29, 10:29:16 (67.210.155.86)
"Speaker distortions tend to be of a more benign nature, typically low order, and seldom accompanied by higher order distortions until you get to the limits of the drivers and system itself... "The fr .......
25: Speaker Asylum, RE: Speakers with most "natural, lifelike" reproduction of vocals? (0.00)
Posted by Duke on 2020-08-18, 21:06:21 (67.210.155.86)
"What design features/technical aspects do you find to correlate with this quality?" Correct spectral balance both on and off axis. This includes freedom from coloration, and in particular freedom fro .......
26: High Efficiency Speaker Asylum, RE: Which are the most efficient speakers? (0.00)
Posted by Duke on 2020-08-17, 02:02:41 (67.210.155.86)
Not saying it's the MOST efficient, but the Tune Audio Anima is rated at 109 dB. And unlike the Avantgardes, it does not use a separately powered woofer section. Duke .......
27: Speaker Asylum, reflections (0.00)
Posted by Duke on 2020-08-11, 13:06:45 (67.210.155.86)
I'd want to minimize the early reflections, and I'd want the reflections to be spectrally-correct (similar in spectral balance to the direct sound). Two possible approaches come to mind: 1. Dipole spe .......
28: High Efficiency Speaker Asylum, RE: AudioKinesis "Space Generator" and rear-firing compression driver (0.00)
Posted by Duke on 2020-06-10, 22:26:27 (67.210.155.86)
" I prefer to place a comp driver on top of the cabinet (even the tweeter from a three way works for this) and then angle it so that I achieve the longest possible time/distance bounce and play with i .......
29: High Efficiency Speaker Asylum, RE: Two-way Compression-driver setup, why it can sound so good (0.00)
Posted by Duke on 2020-06-10, 21:51:10 (67.210.155.86)
"Active, particularly digital covers with delay, are the way to go. Agree?" I suppose that's one way to go, but with careful driver and horn choices the compression driver's diaphragm ends up the corr .......
30: High Efficiency Speaker Asylum, RE: When does tweeter "waveguide" become horn bandpass device? (0.00)
Posted by Duke on 2020-06-03, 13:40:06 (67.210.155.86)
I have been using waveguide-style horns for fifteen years and they ALL have the bandpass effect Bill describes. They ALL end up with the driver's on-axis response approximating its power response. And .......
31: High Efficiency Speaker Asylum, RE: AudioKinesis "Space Generator" and rear-firing compression driver (0.00)
Posted by Duke on 2020-06-03, 13:05:03 (67.210.155.86)
That's actually a second compression driver on the back of the cabinet, firing through that little elliptical horn. It has its own crossover, with its response tailored for its role. The purpose of th .......
32: High Efficiency Speaker Asylum, RE: Two-way Compression-driver setup, why it can sound so good (0.00)
Posted by Duke on 2020-06-03, 12:36:54 (67.210.155.86)
I agree that good horn-loaded midbass is magnificent. And I'm sure there are things a good 4-way can do better than a good 2-way, and those certainly could outweigh the things a good 2-way can do wel .......
33: High Efficiency Speaker Asylum, Two-way Compression-driver setup, why it can sound so good (0.00)
Posted by Duke on 2020-06-01, 22:40:52 (67.210.155.86)
In my opinion one of the advantages of doing a two-way (instead of three-way) with a single good horn-loaded compression driver has to do with the phase response, and specifically its implications for .......
34: General Asylum, RMAF cancelled, will do full refunds (0.00)
Posted by Duke on 2020-05-19, 11:26:21 (67.210.155.86)
From the e-mail they sent me: "We have determined that the course of action that we must take to remain a viable entity is to cancel our show for 2020. As we stated in March, RMAF will be issuing full .......
35: High Efficiency Speaker Asylum, RE: Speaker-level passive bi-amp implications for tubes-on-top? (0.00)
Posted by Duke on 2020-04-01, 12:25:15 (67.210.155.86)
KanedaK: most Heritage designs from Klipsch are making use of this [very basic, sometimes first-order filters] Duke: Klipsch Heritage speakers do some things very well... KanedaK: whether or not it "w .......
36: High Efficiency Speaker Asylum, RE: Speaker-level passive bi-amp implications for tubes-on-top? (0.00)
Posted by Duke on 2020-04-01, 01:33:10 (67.210.155.86)
"Well yes using that kind of simple analogue 24dB or 12dB crossovers one needs to use drivers in their most linear range and hope for the best..." I understand the attractiveness of a simple and elega .......
37: High Efficiency Speaker Asylum, RE: Speaker-level passive bi-amp implications for tubes-on-top? (0.00)
Posted by Duke on 2020-03-27, 11:06:34 (67.210.155.86)
Thanks for your experienced recommendation for the Sublime Acoustics unit. Thus far every passive crossover I have designed has included equalization, which complicates things. .......
38: High Efficiency Speaker Asylum, RE: Speaker-level passive bi-amp implications for tubes-on-top? (0.00)
Posted by Duke on 2020-03-27, 10:54:01 (67.210.155.86)
That's very encouraging - thanks Tom! .......
39: High Efficiency Speaker Asylum, RE: Speaker-level passive bi-amp implications for tubes-on-top? (0.00)
Posted by Duke on 2020-03-26, 12:32:54 (67.210.155.86)
"BOTH amps will continue to see a full-range signal." Agreed. But is it UNSAFE for some tube amps? "No urge to go to a line-level crossover? either passive or active?" I have run into cases where cust .......
40: High Efficiency Speaker Asylum, Speaker-level passive bi-amp implications for tubes-on-top? (0.00)
Posted by Duke on 2020-03-26, 11:55:38 (67.210.155.86)
Pardon me if this is a newbie question, but I haven't used tube amps with output transformers for years. My understanding is that many of them do not like being operated into an open circuit; that is, .......
41: Speaker Asylum, Thanks for making sure nobody forgets that... (0.00)
Posted by Duke on 2020-03-02, 15:46:42 (67.210.155.204)
...they can purchase a (multiple-award-winning) system which does just about everything I have described in this thread directly from me. I'd hate to have missed out on maximizing that marketing oppor .......
42: Speaker Asylum, RE: Subwoofer Placement (0.00)
Posted by Duke on 2020-03-02, 15:24:45 (67.210.155.204)
Dave_K, thank you for your in-depth reply. I'll just comment on a few things. You asked: "Where does [Floyd Toole] mention that anecdote?" Sound Reproduction: The Acoustics and Psychoacoustics of Loud .......
43: Speaker Asylum, Thank you Craiger56 & Ivan303... (0.00)
Posted by Duke on 2020-02-28, 10:25:18 (67.210.155.204)
... I just talk a good game. Duke .......
44: Speaker Asylum, RE: Most irrational number Phi (0.00)
Posted by Duke on 2020-02-27, 18:23:50 (67.210.155.204)
Yup!! Imo that's the theoretically ideal ratio to use. And 1 - .62 = .38, so if a sub is .62 times the wall length from one corner, then it's .38 times the wall length from the other. So by way of exa .......
45: Speaker Asylum, RE: Subwoofer Placement (0.00)
Posted by Duke on 2020-02-27, 12:34:00 (67.210.155.204)
Your suggestions sound like they come from Todd Welti's investigations of symmetrical subwoofer configurations, which is fine. As Inmate51 noted, rooms are seldom acoustically symmetrical at low frequ .......
46: Speaker Asylum, RE: Subwoofer Placement (0.00)
Posted by Duke on 2020-02-26, 11:03:43 (67.210.155.204)
I would not place any more than one sub in a corner. I'd rather have none in corners than two in corners. Duke .......
47: Speaker Asylum, RE: Subwoofer Placement (0.00)
Posted by Duke on 2020-02-26, 10:20:16 (67.210.155.204)
I have some experience with placing multiple subs in a room; I make a four-sub system called The Swarm. Here are my suggestions: Place the sub which goes the deepest in a corner, perhaps one of the fr .......
48: High Efficiency Speaker Asylum, Oblate spheroid (0.00)
Posted by Duke on 2020-02-18, 12:13:46 (67.210.155.204)
The axi-symmetric (round) Oblate Spheroid profile is the shape which mathematically introduces the least amount of disturbance to the wavefront in transitioning from the exit angle of the compression .......
49: General Asylum, RE: Neil Peart RIP (0.00)
Posted by Duke on 2020-01-10, 21:17:18 (67.210.155.204)
Rest in peace, Neil. Thanks for what you gave us, for the example you set. Duke (Asylum member number 2112) .......
50: Speaker Asylum, RE: Subwoofer cabinet 18x20x48 and two 15" sub drivers (0.00)
Posted by Duke on 2019-09-21, 19:16:58 (67.210.155.204)
Imo when designing a subwoofer system, it makes sense to take the room into account as much as is reasonably possible, and to keep your goalposts in mind, whatever they may be. For instance, imo that' .......
51: Speaker Asylum, Contrarian view (0.00)
Posted by Duke on 2019-04-28, 11:25:32 (67.210.155.204)
Imo it makes sense to take the room into account as much as possible when designing a loudspeaker. If that is correct, then it might also make sense to take the room into account when writing the spec .......
52: High Efficiency Speaker Asylum, Duet (0.00)
Posted by Duke on 2019-03-29, 15:54:19 (67.210.155.204)
I remember listening to a three-way horn system where the tweeter horn's mouth was in the same plane as the midrange horn's mouth, putting the tweeter horn's diaphragm multiple wavelengths closer to t .......
53: Speaker Asylum, RE: Hillbilly hot rod... (0.00)
Posted by Duke on 2019-03-04, 13:55:56 (67.210.155.204)
Faital horn with 1.4" driver! VERY nice!! .......
54: High Efficiency Speaker Asylum, In other words, audiphiles REALLY DO listen with their eyes! (0.00)
Posted by Duke on 2019-03-02, 17:25:42 (67.210.155.204)
We fans of big ugly horns have known that all along. ;^) Seriously, VERY interesting article, thank you for the link. Duke .......
55: Speaker Asylum, RE: Hillbilly hot rod... (0.00)
Posted by Duke on 2019-03-02, 14:16:34 (67.210.155.204)
Looks great! Acoustic Elegance or Lambda Acoustics woofer I assume... Apollo upgrade I think... but I can't place the horn! It looks kinda like an 18Sound. What is it? And I can't begin to guess the .......
56: Speaker Asylum, Agreed. (0.00)
Posted by Duke on 2019-03-02, 13:15:33 (67.210.155.204)
I was addressing the "REALLY NEED" aspect of the original post. Duke .......
57: Speaker Asylum, Depends on whether dialogue is anchored on-screen for off-centerline viewers (0.00)
Posted by Duke on 2019-03-01, 13:33:26 (67.210.155.204)
Ime it is possible to use aggressive toe-in of the main speakers and not need a center channel. I have customers who have sold their center channel speakers because they didn't need 'em, as the timbre .......
58: Speaker Asylum, RE: How to know if I REALLY NEED a centre speaker?! (0.00)
Posted by Duke on 2019-03-01, 13:23:23 (67.210.155.204)
Ah yes, I see the subs now. I'm almost disappointed that those weren't teenytinyconed subwoofers. Not that I'm necessarily all about small and cute (as you saw in my room at RMAF last year), but the t .......
59: Speaker Asylum, RE: Almost reminds me of one of your own... (0.00)
Posted by Duke on 2019-03-01, 10:24:55 (67.210.155.204)
The floor bounce notch ends up being well north of the frequencies where a passive radiator would be active, and yes I prefer ports. I use the modular Precision Ports, whose lengths can be changed to .......
60: Speaker Asylum, It's definitely a juggling of tradeoffs! (0.00)
Posted by Duke on 2019-03-01, 10:19:35 (67.210.155.204)
I have three speaker designs with twin 12" midbasses, two in the "MHM" format like the Tyler, and one in "HMM" format like Peter's. Imo "MHM" is arguably a bit better, but it sure ends up being a tall .......
61: Speaker Asylum, RE: How to know if I REALLY NEED a centre speaker?! (0.00)
Posted by Duke on 2019-03-01, 10:11:00 (67.210.155.204)
Wow, just BEAUTIFUL! I completely missed the rounded center piece in that first photo, and was wondering why your subwoofers had such tiny cones. I remember Roger West of SoundLab recommending bendi .......
62: Speaker Asylum, RE: How to know if I REALLY NEED a centre speaker?! (0.00)
Posted by Duke on 2019-02-28, 23:26:57 (67.210.155.204)
Very nice system, very nice room, and very interesting ceiling treatments. I saw something similar on the ceiling of Earl Geddes' dedicated room. Thanks for sharing the photo. Duke .......
63: Speaker Asylum, I was responding to... (0.00)
Posted by Duke on 2019-02-28, 11:19:45 (67.210.155.204)
...this: "I've heard the JBL M2, and it is quite good, but I generally don't care for speakers which require me to sit/stand in a certain place in order to hear good sound." Seemed like you were imply .......
64: Speaker Asylum, Little brother, the M1!5 (0.00)
Posted by Duke on 2019-02-28, 10:44:33 (67.210.155.204)
Peter also makes a smaller version, link below. Duke .......
65: Speaker Asylum, How to get that super-wide sweet spot (0.00)
Posted by Duke on 2019-02-28, 10:41:53 (67.210.155.204)
It's a common misconception that big woofers = small sweet spot. With the right design (and it doesn't get any righter than the M2!5), the sweet spot can be very large. Let me explain: The ear localiz .......
66: Speaker Asylum, I heard 'em at RMAF 2018. (0.00)
Posted by Duke on 2019-02-27, 23:23:18 (67.210.155.204)
They were not being played loudly. In my opinion Peter Noerbaek's M2!5's are utterly magnificent. No horn signature, no coloration, totally relaxing. Superb at conveying emotion (which musicians use d .......
67: High Efficiency Speaker Asylum, Horn choice is critical, as is crossover design (0.00)
Posted by Duke on 2019-02-09, 15:19:21 (67.210.155.204)
When I first heard the Faital 3FE22 (neodymium version of yours), I thought, oboy I could build a speaker around this little guy! However when comparing it to a good horn/compression driver combinatio .......
68: High Efficiency Speaker Asylum, RE: Possibly Dumb Question (0.00)
Posted by Duke on 2019-01-29, 14:41:46 (67.210.155.204)
Yes, about ten years ago I had a conversation with someone who had designed transmission line speakers professionally back in the 80's, and was quite surprised when he told me how high the Qts was on .......
69: High Efficiency Speaker Asylum, RE: Possibly Dumb Question (0.00)
Posted by Duke on 2019-01-28, 19:39:58 (67.210.155.204)
They were stuffed, but not very heavily stuffed. It seemed to me like there was a tradeoff relationship between adequate low bass and good upper bass, as the stuffing density was varied. In retrospec .......
70: Speaker Asylum, RE: Aren't subwoofers mostly omni-directional? (0.00)
Posted by Duke on 2019-01-28, 15:39:49 (67.210.155.204)
Of course subs are omnidirectional. Placing all of the subs on the floor does nothing for modal smoothing in the vertical plane. The symptoms described imply a significant "null" is occurring in the v .......
71: High Efficiency Speaker Asylum, RE: Possibly Dumb Question (0.00)
Posted by Duke on 2019-01-28, 15:02:31 (67.210.155.204)
"But rear loaders have their own issue, the response dip where the front and rear waves meet 180 degrees out of phase." I built more unsuccessful transmission line boxes than you could shake a stick a .......
72: Speaker Asylum, RE: Best way to raise a subwoofer 5 feet off the ground? (0.00)
Posted by Duke on 2019-01-28, 14:58:47 (67.210.155.204)
Perhaps atop a bookcase or something similar. Two small subs might be more practical than one big one (aside from offering further advantages in modal smoothing). Perhaps by something custom. My broth .......
73: Speaker Asylum, Imo you might benefit from modal smoothing in the vertical plane. (0.00)
Posted by Duke on 2019-01-27, 15:56:18 (67.210.155.204)
My suggestion would be to add a subwoofer or two, closer to the ceiling than to the floor, but not all the way up at the ceiling. If you can add two, try to place them at significantly different heigh .......
74: High Efficiency Speaker Asylum, Yup. (0.00)
Posted by Duke on 2018-11-08, 20:20:58 (67.210.155.204)
And Bruce Edgar knows how to design good ones. Duke .......
75: High Efficiency Speaker Asylum, bad horn geometry (0.00)
Posted by Duke on 2018-11-08, 20:10:12 (67.210.155.204)
The most likely culprit at home-audio listening levels is, bad internal geometry in the horn. Air non-linearity due to compression is not an issue until the SPL goes up much higher. Discontinuities in .......
76: General Asylum, Permission request (0.00)
Posted by Duke on 2018-10-11, 23:33:24 (67.210.155.204)
Hi Rod, I don't know how to contact you aside from here, so I hope you don't mind. May I have permission to use the pictures you posted in this thread? If so, let me know the wording you would like fo .......
77: Speaker Asylum, RE: Thanks for the advice and comments (0.00)
Posted by Duke on 2018-10-11, 22:33:55 (67.210.155.204)
Whereabouts are you located? Could you live with subwoofers disguised as speaker stands? Duke .......
78: General Asylum, RE: Best of Show? (0.00)
Posted by Duke on 2018-10-11, 18:45:32 (67.210.155.204)
Thank you very much, Rod!! (It's actually spelled "AudioKinesis", in case anyone tries to look us up.) Duke .......
79: General Asylum, RE: Day Two Winners at RMAF (0.00)
Posted by Duke on 2018-10-08, 20:53:24 (67.210.155.204)
"The only reason I mentioned it, is because I am in the market for new speakers." The entire system is a bit more involved than is obvious at first glance. Feel free to shoot me an e-mail if you'd lik .......
80: General Asylum, RE: Day Two Winners at RMAF (0.00)
Posted by Duke on 2018-10-08, 20:44:34 (67.210.155.204)
Thank you very much, Rod!! The Azel Stand Mounts are brand new, though the ideas they embody are things I have been doing for a while, refined a bit here and there. Duke .......
81: High Efficiency Speaker Asylum, That can be done passively too. (0.00)
Posted by Duke on 2018-09-04, 19:19:52 (67.210.155.204)
"The new frontier is DSP-based controlled directivity speakers, which employ multiple drivers and phase manipulation to provide the same directivity at all frequencies, so you hear the same mix no mat .......
82: High Efficiency Speaker Asylum, RE: Beaming (0.00)
Posted by Duke on 2018-09-04, 13:52:38 (67.210.155.204)
I fall into the camp that believes the off-axis response usually matters even if you sit in the sweet spot. Unless you listen nearfield, most of the sound that reaches your ears is reverberant sound .......
83: High Efficiency Speaker Asylum, Magnificent example of choosing not to reply in kind. (0.00)
Posted by Duke on 2018-09-01, 21:13:58 (67.210.155.204)
Freddyi, you rock!! Duke .......
84: High Efficiency Speaker Asylum, RE: Really? this enire Forum is the personal Phantasy arena for Freddyi? (0.00)
Posted by Duke on 2018-09-01, 21:12:00 (67.210.155.204)
I was once witness to a truly amazing demonstration of what someone with limited hearing can still differentiate by paying close attention. The speaker designer in question has very poor hearing in on .......
85: Speaker Asylum, RE: Could Someone Who Understands (0.00)
Posted by Duke on 2018-08-31, 20:21:45 (67.210.155.204)
I suggest two 2" diameter ports, each 5" long. Make sure the inner diameter is actually 2.0 inches or very close to it. The reason is, this will give you the option of plugging one of the ports with a .......
86: Speaker Asylum, RE: In this case it makes sense to me (0.00)
Posted by Duke on 2018-08-14, 11:43:45 (67.210.155.204)
Sweet! Thanks for letting me know! .......
87: Speaker Asylum, RE: In this case it makes sense to me (0.00)
Posted by Duke on 2018-08-13, 14:11:30 (67.210.155.204)
Thanks for posting your results! Imo the "optimum" target response curve is a little bit different for the crossfiring configuration, as you are listening from somewhat off-axis. So the target curve m .......
88: Speaker Asylum, In this case it makes sense to me (0.00)
Posted by Duke on 2018-08-13, 00:59:43 (67.210.155.204)
The JBL M2's have excellent radiation pattern control. Here is why that matters a lot in a small room: Early reflections are generally detrimental, but when they are inevitable it is best if they have .......
89: Speaker Asylum, Alternative (0.00)
Posted by Duke on 2018-07-15, 20:21:55 (67.210.155.204)
I'm not a fan of piezos. Several years ago I went on a piezo-quest for a bass guitar speaker system. I was trying to make a lightweight bass cab that still sounded pretty good, and piezos are very li .......
90: Speaker Asylum, A few things to consider (0.00)
Posted by Duke on 2018-07-13, 00:56:31 (67.210.155.204)
Without really knowing where your "goal posts" are, these thoughts come to mind: Obviously you are looking for speakers that have much higher SPL capability than whatever you have been using. Prosound .......
91: High Efficiency Speaker Asylum, RE: Room 3002, in the Tower (0.00)
Posted by Duke on 2018-06-13, 19:43:53 (67.210.155.204)
Who you callin' an MF'R?? Seriously, looking forward to meeting you, Dennis! I've used tube amps at most audio shows, but this year it looks like solid state is on the menu. Duke .......
92: Speaker Asylum, RE: Subwoofer suggestions (0.00)
Posted by Duke on 2018-06-13, 19:08:55 (67.210.155.204)
I don't have diddly going on in Princeton, as far as home audio goes. no home showroom, and none of the cabinet making shops around here will even have a conversation with me about building speaker en .......
93: Speaker Asylum, RE: Subwoofer suggestions (0.00)
Posted by Duke on 2018-06-12, 15:02:00 (67.210.155.204)
When it comes to the bottom couple of octaves in a home audio setting, the elephant in the room IS the room. The room imposes huge peaks and dips on the output of a subwoofer that ruin its response, n .......
94: High Efficiency Speaker Asylum, Room 3002, in the Tower (0.00)
Posted by Duke on 2018-06-12, 06:52:47 (67.210.155.204)
I'll be there, Room 3002, with Jim Romeyn. In fact today I'm drawing the enclosure plans for the speakers we'll be bringing. Duke .......
95: High Efficiency Speaker Asylum, RE: Sweet TAD/Altec-friendly woofer enclosures (0.00)
Posted by Duke on 2018-06-11, 21:24:51 (67.210.155.204)
Yeah, finding the best place for the tweeter in a three-way with a mid horn is a challenge. If money were no object, I'd want to try two tweeters per side: One front-firing in whatever location sound .......
96: High Efficiency Speaker Asylum, Sweet TAD/Altec-friendly woofer enclosures (0.00)
Posted by Duke on 2018-06-11, 19:45:31 (67.210.155.204)
A friend of mine from my New Orleans days has retired and is downsizing, so he is selling his custom high-efficiency speaker system. TAD 16" woofers in 9.5 cubic feet, JBL 2441's with Beryllium diaphr .......
97: Speaker Asylum, RE: Thanks for posting Duke.. (0.00)
Posted by Duke on 2017-09-29, 23:59:28 (67.210.155.40)
Thank you Lee, looking forward to seeing you again! Duke .......
98: Speaker Asylum, RE: RMAF 2017, "Innovations" rooms (0.00)
Posted by Duke on 2017-09-28, 15:46:10 (67.210.155.40)
Will do... but I don't have the handout done yet. .......
99: Speaker Asylum, RE: I will be looking forward to seeing you there! (0.00)
Posted by Duke on 2017-09-28, 15:45:05 (67.210.155.40)
Glad to hear you're getting around better now, but please don't overdo it! Duke .......
100: Speaker Asylum, RMAF 2017, "Innovations" rooms (0.00)
Posted by Duke on 2017-09-27, 17:34:00 (67.210.155.40)
At the upcoming Rocky Mountain Audio Fest, on the second floor of the Tower, there will be four "Innovations Rooms". The mandate for these rooms includes, be visitor-friendly... like, accept and accom .......
101: High Efficiency Speaker Asylum, For some reason my edits are getting truncated (0.00)
Posted by Duke on 2017-06-15, 16:54:43 (67.210.155.40)
Let me try again: To answer your question: Of course, but the overload is not because the room is behaving differently as the level goes up; it is because our ears are perceiving differently as the le .......
102: High Efficiency Speaker Asylum, plug for Hedback Designed Acoustics (0.00)
Posted by Duke on 2017-06-15, 16:40:49 (67.210.155.40)
To answer your question: Of course, but the overload is not because the room is behaving differently as the level goes up; it is because our ears are perceiving differently as the level goes up. Havin .......
103: High Efficiency Speaker Asylum, No.... and, yes. (0.00)
Posted by Duke on 2017-06-15, 15:59:10 (67.210.155.40)
The patterns, intensity, and spectral content of room reflections increase LINEARLY as the SPL coming out of the speakers goes up. So, from the standpoint of acoustics, room effects are NOT level-depe .......
104: Speaker Asylum, RE: I've found Toole's research to be extremely valuable (0.00)
Posted by Duke on 2017-05-30, 19:55:17 (67.210.155.40)
I won't be at the Capital Audio Show, sorry. Nearly all of my energy has been going into prosound projects lately - some musical instrument speaker cabinets, and some studio speaker designs. Duke :: .......
105: Speaker Asylum, RE: I've found Toole's research to be extremely valuable (0.00)
Posted by Duke on 2017-05-30, 18:56:13 (67.210.155.40)
So... we disagree, but there's enough common ground that we can both stand on it? Done! Thank you for such an agreeable disagreement! Duke .......
106: Speaker Asylum, I've found Toole's research to be extremely valuable (0.00)
Posted by Duke on 2017-05-30, 13:36:21 (67.210.155.40)
I've learned things, imo very valuable things, from Toole and/or others' research that he renders accessible in his writings. Want to learn what matters most in speaker design? As you juggle the inevi .......
107: Speaker Asylum, Excellent question! (0.00)
Posted by Duke on 2017-05-30, 01:18:04 (67.210.155.40)
"Which of Toole's conclusions do you disagree with, and why?" One of the conclusions Toole apparently draws from his data is, wide dispersion speakers are the way to go if that wide dispersion is high .......
108: Speaker Asylum, Methodology problem imo (0.00)
Posted by Duke on 2017-05-30, 00:39:12 (67.210.155.40)
The methodology used is not dipole-friendly, and is even less dipole-panel/box-woofer-hybrid-friendly. Let me explain: One of the main benefits of a dipole speaker is its spectrally-correct backwave e .......
109: High Efficiency Speaker Asylum, Yes. (0.00)
Posted by Duke on 2017-05-29, 20:34:57 (67.210.155.40)
I routinely use aggressive toe-in, ballpark 45 degrees, such that the speaker axes criss-cross a couple of feet in front of the listening area. The speakers I do this with are woofer/horn hybrids, wi .......
110: Speaker Asylum, RE: Zu Soul Supreme sensitivity (0.00)
Posted by Duke on 2017-05-28, 00:04:33 (67.210.155.40)
"Why doesn't every component that measures the same sound the same?" If one is willing to delve into the details, it would be extremely unlikely to find two different loudspeakers that really do measu .......
111: Speaker Asylum, RE: Bother, I meant SWARM, not storm. (0.00)
Posted by Duke on 2017-05-10, 00:18:35 (67.210.155.40)
A SubHenge. Sweet! That works and works well, in my experience. If you have the ability to adjust phase, you might try putting the two subs on the left in "phase quadrature" (90 degrees of phase shif .......
112: Speaker Asylum, RE: Imo this would be wrong for MAKING dubstep (0.00)
Posted by Duke on 2017-02-03, 23:46:56 (67.210.155.40)
I'm not trying to tell you what to listen to for your own enjoyment. What I'm trying to tell you is that, in my opinion, the system you've described is the wrong tool for making recordings for other .......
113: Speaker Asylum, Imo this would be wrong for MAKING dubstep (0.00)
Posted by Duke on 2017-02-02, 12:30:58 (67.210.155.40)
So let's say this sub + tweeter arrangement sounds good to you when you listen to your dubstep creations through it, because the bass and treble are over-emphasized. Now what happens when your music i .......
114: Speaker Asylum, Adjustability (0.00)
Posted by Duke on 2016-10-30, 11:43:24 (67.210.155.40)
I agree that we would not want too strong and distinct ("specular") a reflection from the upfiring array, but in practice we're usually getting reflections off of both nearby walls as well as the ceil .......
115: Speaker Asylum, A little bit, but the later reflections are many times stronger (0.00)
Posted by Duke on 2016-10-29, 11:31:40 (67.210.155.40)
The upfiring array in the photo you posted consists of two 8" woofers and a 90-by-45 degree horn, in an "MHM" arrangement. The secret weapon is the main speaker - it acts as a "shield" so that there i .......
116: Speaker Asylum, RE: Excellent point (0.00)
Posted by Duke on 2016-10-29, 11:06:58 (67.210.155.40)
Auditory thresholds are usually somewhat fuzzy in the time domain, and reflection detection thresholds do indeed vary with level and frequency and direction, and the subjective effect of said reflecti .......
117: Speaker Asylum, Excellent point (0.00)
Posted by Duke on 2016-10-27, 11:13:05 (67.210.155.40)
Ten milliseconds is about where the reflections become clearly beneficial; before that they're more of a mixed blessing, and arguably outright undesirable before 6 milliseconds ( I make 10 millisecond .......
118: Speaker Asylum, RE: Not yet...? (0.00)
Posted by Duke on 2016-10-27, 09:48:32 (67.210.155.40)
I would prefer to reply to you privately, but your profile doesn't accept e-mails. Could you e-mail me? Thanks! Duke .......
119: Speaker Asylum, RE: Not yet...? (0.00)
Posted by Duke on 2016-10-27, 09:05:53 (67.210.155.40)
You're right! Somehow the info on the rear-firing tweeter got dropped. Thanks for letting me know! The "entry level Two Streams" speaker won't be a Prisma variant, it'll be its own thing. Soon as I ha .......
120: Speaker Asylum, Not yet... working on it (0.00)
Posted by Duke on 2016-10-26, 21:49:30 (67.210.155.40)
The rear-firing tweeter on the Prisma is compensation for the rectangular front horn's radiation pattern, which is narrower in the vertical plane than in the horizontal. When I match up the horizonta .......
121: Speaker Asylum, RE: Excellent points - I'll try to address them... (0.00)
Posted by Duke on 2016-10-26, 16:51:31 (67.210.155.40)
Thanks for your kind reply! "The Avantgardes sounded great in my London living room (5 sided with big bay, 350 sq ft, 10 ft ceilings and nice soft Victorian plaster walls) but they're sadly not so ha .......
122: Speaker Asylum, RE: Speakers Have The Toughest Job (0.00)
Posted by Duke on 2016-10-26, 13:08:47 (67.210.155.40)
To add to your list: Most of the other audio components are dealing with voltage variations over time. The speaker has to convert voltage variations over time into mechanical motion over time which in .......
123: Speaker Asylum, RE: Dispersion patterns (0.00)
Posted by Duke on 2016-10-26, 12:52:08 (67.210.155.40)
"But an important fact which hasn't been mentioned in this thread is the fact that not all instruments radiate their sound in the same manner. A trumpet sounds very different at different angles from .......
124: Speaker Asylum, Two-streams done well comes pretty close (0.00)
Posted by Duke on 2016-10-26, 11:06:16 (67.210.155.40)
Posted by TAS reviewer Andrew Quint on another forum, about hearing a recording he was familiar with, made in a hall he was familiar with, played through a set of my "Two Streams Paradigm" speakers: " .......
125: Speaker Asylum, But it's still a closer approximation (0.00)
Posted by Duke on 2016-10-26, 10:58:42 (67.210.155.40)
Dave: It isn't the speakers that need fixing. It's the room. Duke: They need to work together. Having heard what a professionally treated room can sound like, I readily agree that the room can make a .......
126: Speaker Asylum, RE: How much reverberation was captured in the original recording (0.00)
Posted by Duke on 2016-10-26, 10:22:45 (67.210.155.40)
The ear/brain system is better able to pick out the reverberant information in the recording when it's presented this way, versus when it's presented conventionally. In fact, the worst possible direct .......
127: Speaker Asylum, Excellent points - I'll try to address them... (0.00)
Posted by Duke on 2016-10-26, 09:59:36 (67.210.155.40)
Cawson: This is an interesting theory, but questions must be asked as the theory is put forward by the manufacturer of a loudspeaker brand that attempts to comply with this theory! Duke: True! C: Fir .......
128: Speaker Asylum, RE: "Two Streams Paradigm" speakers? (0.00)
Posted by Duke on 2016-10-25, 14:34:43 (67.210.155.40)
Dipoles positioned well out into the room meet the "Two Streams" criteria, as long as the spectral balance of the backwave is the same as that of the frontwave. Most omnis are going to have significan .......
129: High Efficiency Speaker Asylum, Stuffing (0.00)
Posted by Duke on 2016-10-25, 13:32:07 (67.210.155.40)
Regardless of how powerful the woofer's magnet is, its effective electrical Q is modified by the amplifier's output impedance. This effect is the sum total of damping factor's influence on the bass re .......
130: Speaker Asylum, Immersive (0.00)
Posted by Duke on 2016-10-25, 10:29:12 (67.210.155.40)
You mentioned that you are looking for "Immersive like a concert." Concert hall designer, researcher, and psychoacoustics expert David Griesinger uses the word "envelopment" to describe the sound in t .......
131: Speaker Asylum, RE: Swarm clone (0.00)
Posted by Duke on 2016-07-14, 22:39:40 (67.210.155.40)
First of all, I am honored that you think highly enough of my Swarm system to want to roll your own! "The idea is to use multiple small diameter subs to smooth out room response and maintain the "quic .......
132: Speaker Asylum, RE: Opportunities & misconceptions. (0.00)
Posted by Duke on 2016-06-02, 19:06:06 (67.210.155.40)
Ahem, yes well... I always do my best proofreading AFTER I hit "Post"... .......
133: Speaker Asylum, Thanks for this opportunity to reply to so many misconceptions (0.00)
Posted by Duke on 2016-06-02, 14:55:20 (67.210.155.40)
I'm not being facetious Mike, I really do appreciate the opportunity. Lots of people have misconceptions about multisub systems, and you've just brought up several of them. "The "swarm" approach reco .......
134: Speaker Asylum, RE: That makes sense for a woofer, not a subwoofer (0.00)
Posted by Duke on 2016-06-02, 00:16:45 (67.210.155.40)
After several bounces around the room, the initial advantage dipoles have in the bass due to their directivity is reduced because all of the modes will eventually be excited. Still I concede that a di .......
135: Speaker Asylum, RE: incorrect assertion. (0.00)
Posted by Duke on 2016-06-01, 23:55:26 (67.210.155.40)
I think you confusing "omnidirectional" (a property of a sound source) with "non-localizable" (the inability of human hearing to tell where a sound is coming from). Dipoles are not omnidirectional. T .......
136: Speaker Asylum, RE: Recommended studio-accurate subwoofer? (0.00)
Posted by Duke on 2016-05-31, 12:02:18 (67.210.155.40)
Thanks for your replies to my quesions. The woofer getting worked at low frequencies isn't contributing much useful bass, as below the 42 Hz ballpark tuning frequency the woofer will be out-of-phase w .......
137: Speaker Asylum, Not necessarily (0.00)
Posted by Duke on 2016-05-31, 11:27:03 (67.210.155.40)
I have a customer who has a Meridian processor that has 60 programmable digital filters for smoothing out the region below 250 Hz. When he was using a single subwoofer, he had the system professionall .......
138: Speaker Asylum, RE: Recommended studio-accurate subwoofer? (0.00)
Posted by Duke on 2016-05-30, 22:49:37 (67.210.155.40)
I'm certainly not up on everything out there in the world of 2.5 grand subwoofers, but here are some thoughts... I don't know of any subwoofer in that price ballpark that has a variable-frequency high .......
139: General Asylum, RE: Thanks for listening with your ears instead of your eyes! (0.00)
Posted by Duke on 2016-04-21, 14:16:41 (67.210.155.40)
Wow, small world! Great to cross paths with you again here. Needless to say, your comments were and are very much appreciated, and I also thank your friend who accompanied you to our room. Duke ::: .......
140: General Asylum, Thanks for listening with your ears instead of your eyes! (0.00)
Posted by Duke on 2016-04-20, 21:36:44 (67.210.155.40)
"They do have a horn but I didn't hear any negatives people sometimes attribute to horns speakers." Every year we have a lot of people stick their heads into the room far enough to see the horns at wh .......
141: Speaker Asylum, RE: sealed boxes with push-pull bass drivers (0.00)
Posted by Duke on 2016-04-05, 15:37:46 (67.210.155.40)
I think the "halving of Vas" theory fails to tell the whole story. I think you can expect a bit deeper F3 than the current theory predicts, at least that has been my experience. I'm not sure what the .......
142: Speaker Asylum, RE: Speaker Recommendations for my Missile Silo (0.00)
Posted by Duke on 2016-03-26, 21:20:30 (67.210.155.40)
Hi GT, Thanks for not running screaming from the forum when I suggested that a pretty substantial subwoofer presence was called for. Just for the record, I'm an "award winning" subwoofer designer (inc .......
143: Speaker Asylum, RE: Speaker Recommendations for my Missile Silo (0.00)
Posted by Duke on 2016-03-26, 19:32:18 (67.210.155.40)
If we assume that the three levels are effectively one airspace because of the "rattle space" encircling the rooms and connecting them, then if my math is correct, the internal volume you're trying to .......
144: Speaker Asylum, RE: Speaker Recommendations for my Missile Silo (0.00)
Posted by Duke on 2016-03-26, 13:06:39 (67.210.155.40)
Your description of what's missing sounds like there may be a "hole" in between the mains and subs. My guess is that the mains were designed to have a lot of boundary reinforcement and they just aren' .......
145: Speaker Asylum, As a ballpark rule of thumb... (0.00)
Posted by Duke on 2016-02-18, 21:01:55 (67.210.155.40)
...two subs intelligently placed will be roughly twice as smooth in-room as a single sub. And four subs intelligently placed will be roughly twice as smooth as two. This smoothness will also hold up o .......
146: High Efficiency Speaker Asylum, RE: Parallel Inductors in Passive Crossovers (0.00)
Posted by Duke on 2016-02-07, 13:06:22 (67.210.155.40)
A resistor on a parallel leg of the circuit damps that leg. Whatever the resulting filter might be called, assuming competent design, the resistor is there to help tailor the frequency response and/or .......
147: Speaker Asylum, RE: Advice on building a pair of passive Subwoofers.. (0.00)
Posted by Duke on 2015-12-17, 22:58:35 (67.210.155.16)
You need to use a real subwoofer driver, and that's not one. Look at Madisound, Parts Express, etc. Passive crossovers are easy to design, but good ones are hard to design. You need to start out with .......
148: Speaker Asylum, RE: Technical question re. speaker crossover (0.00)
Posted by Duke on 2015-12-15, 19:51:59 (67.210.155.16)
Increasing the series resistance will, in addition to padding down the tweeter, change the shape of the response curve in the crossover region. This may or may not be audible. I'd say go ahead and tr .......
149: Speaker Asylum, RE: Looking For help with Open Baffel Project (0.00)
Posted by Duke on 2015-11-23, 07:30:57 (67.210.155.16)
I suggest trying what you've got first. Above the frequency where dipole cancellation sets in (which in turn depends on your baffle width), a dipole puts out more energy than a monopopole because you .......
150: Speaker Asylum, RE: Resistance/Ohms and SPL (0.00)
Posted by Duke on 2015-10-31, 20:01:57 (67.210.155.16)
Can you describe where the Maggies are in your 40 x 12 room, and where they are in his 18 x 18 room? Imo amp + speakers + room = "a system within a system", they all three matter, hence my question. .......
151: Speaker Asylum, RE: Resistance/Ohms and SPL (0.00)
Posted by Duke on 2015-10-31, 12:06:32 (67.210.155.16)
"The "better sounding speakers" are of the low ohm version for the most part." Well ime there are enough exceptions to this statement to prevent it from being any kind of rule. If we know in advance .......
152: Speaker Asylum, What really matters to the ears? (0.00)
Posted by Duke on 2015-10-31, 11:43:25 (67.210.155.16)
"But why are the sonic's so different using the same equipment with simply changing the speakers, or even more so, changing x-over points in the same speaker array using the same equipment?" Briefly, .......
153: Speaker Asylum, RE: Subwoofers and speaker polarity (0.00)
Posted by Duke on 2015-10-31, 11:25:21 (67.210.155.16)
So is the polarity reversed on just one of the TADs, or on both? In either event, it sounds like you are getting a smoother transition to the Tannoys now. If we knew what was happening with each of t .......
154: Speaker Asylum, RE: Which is the way that's clear?? (0.00)
Posted by Duke on 2015-10-26, 09:33:31 (67.210.155.165)
Diffusion would probably help. Polydirectional speakers are what I was thinking of. ESP, Shahinian, and yours truly build speakers which can generate a soundstage that transcends the room's boundarie .......
155: Speaker Asylum, Which is the way that's clear?? (0.00)
Posted by Duke on 2015-10-25, 21:37:32 (67.210.155.165)
Stiiiill lookin' for that blue jean baby queen... Oops, sorry. Okay in my experience, soundstage depth is usually limited by how far in front of the wall the speakers are. If the speakers are two fee .......
156: High Efficiency Speaker Asylum, RE: Depicting high impedance capability for SET's (0.00)
Posted by Duke on 2015-09-01, 15:15:20 (67.210.155.165)
I routinely design speakers to work well with tube amps having an output of 4 ohms or greater (damping factor = 2 or less). Here are a couple of things I've found to work well: - Shoot for a relativel .......
157: Speaker Asylum, RE: My Dear Friend, Bobby Palkovich (Merlin Music Systems) - Rest In Peace (0.00)
Posted by Duke on 2015-08-26, 15:49:35 (67.210.155.165)
Rest in peace Bobby. You brightened many lives and helped bring beautiful music into many homes where it could work its magic to full effect. .......
158: High Efficiency Speaker Asylum, Toe-in (0.00)
Posted by Duke on 2015-08-23, 23:55:48 (67.210.155.165)
I have customers who have sold their center channels after trying horn speakers toed in such that the axes criss-cross in front of the listening area. With a constant-directivity horn, this gives good .......
159: OTL Asylum, Something to watch for (0.00)
Posted by Duke on 2015-08-23, 23:33:25 (67.210.155.165)
Aside from decent efficiency and an impedance curve that doesn't dip too low, a fairly smooth impedance curve is desirable. Assuming the speakers were voiced on solid state amps (most are), be aware t .......
160: Speaker Asylum, RE: Loudspeaker directivity should be a top priority (0.00)
Posted by Duke on 2015-07-26, 21:36:00 (67.210.155.165)
"A question comes to mind: Is it possible to make a "time coherent" speaker using the precepts prescribed by you in the above paragraphs?" In a passive loudspeaker, imo the compromises required to get .......
161: Speaker Asylum, Another reason (0.00)
Posted by Duke on 2015-07-26, 21:10:12 (67.210.155.165)
Another reason why loudspeaker directivity matters is, for the sake of long-term fatigue-free listening. What follows has not, to the best of my knowledge, been the subject of controlled blind testing .......
162: Speaker Asylum, Loudspeaker directivity should be a top priority (0.00)
Posted by Duke on 2015-07-26, 20:23:31 (67.210.155.165)
One of the main reasons loudspeaker directivity matters is, unless we listen nearfield or under approximately anechoic conditions, most of the sound that reaches our ears is reverberant energy - that .......
163: Speaker Asylum, RE: $1000 Be tweeters (0.00)
Posted by Duke on 2015-07-05, 20:33:25 (67.210.155.165)
What do I like about a good Beryllium driver? Articulation with smoothness, I guess you'd call it. Back in 2001 I worked on a project that would have used a Pioneer TAD Beryllium diaphragm compressio .......
164: High Efficiency Speaker Asylum, RE: Choose a Low Pass (0.00)
Posted by Duke on 2015-07-05, 19:23:49 (67.210.155.165)
I never approach a design with a crossover point in mind, but I always approach a design with the off-axis response and system dynamic capabilities and overall synergy very much in mind. The specific .......
165: High Efficiency Speaker Asylum, RE: Choose a Low Pass (0.00)
Posted by Duke on 2015-07-05, 17:53:46 (67.210.155.165)
Assuming both drivers have acceptable response over the region in question, I'd first want to figure out whether the midbass driver will be overstressed in this application with the lower crossover po .......
166: Speaker Asylum, RE: Anyone compared Studio Monitor vs Floorstanders? (0.00)
Posted by Duke on 2015-07-03, 19:46:49 (67.210.155.165)
The JBL 7 series looks good to me on paper in most respects... I also use waveguide-style horns in a two-way format. Imo it's important to get the radiation patterns of midwoof and tweeter section to .......
167: Speaker Asylum, RE: Anyone compared Studio Monitor vs Floorstanders? (0.00)
Posted by Duke on 2015-07-01, 23:54:49 (67.210.155.165)
I build both so I've compared them, but obviously only my own builds. My studio monitor builds are customized for the specified placement in that particular studio (I work closely with the acoustician .......
168: Speaker Asylum, Yes (0.00)
Posted by Duke on 2015-07-01, 23:04:22 (67.210.155.165)
I offer the Radian Beryllium compression driver as an upgrade on some of my floorstanding models. They are NOT a drop-in replacement for an "equivalent" conventional driver - a complete redesign of th .......
169: Speaker Asylum, Yes (0.00)
Posted by Duke on 2015-04-04, 10:05:36 (71.252.147.45)
I do a four-piece subwoofer system that uses a single external amplifier, so the amp could just be omitted, and you'd have four subs with speaker inputs. They are intended to be wired in series-parall .......
170: Speaker Asylum, Two thumbs up (0.00)
Posted by Duke on 2015-03-20, 20:55:16 (208.98.182.143)
I just got a sample from FoamSpeakerGrilles.com. It looks great. I became aware of the company through a review in Voice Coil, a loudspeaker industry newsletter magazine. Apparently this is virtually .......
171: High Efficiency Speaker Asylum, RE: Efficiency & Resistance (0.00)
Posted by Duke on 2015-02-15, 15:26:25 (208.98.182.143)
"In terms of headroom, usually an amplifier reaches Voltage clipping first or Current limiting first, the most headroom / largest peak power is had with a load where both are reached at essentially th .......
172: High Efficiency Speaker Asylum, RE: Sweet spot width (0.00)
Posted by Duke on 2015-01-31, 00:21:32 (208.98.182.143)
It looks to me like the Concerto 4's waveguide is only about 4" wide, and the woofers are 8" in diameter. There will be a pattern mismatch in the crossover region, and pattern control will not extend .......
173: High Efficiency Speaker Asylum, Sweet spot width (0.00)
Posted by Duke on 2015-01-29, 22:14:35 (208.98.182.143)
"Most of my listening is shared with my wife, so neither of us is sitting dead center between the speakers (more like the 30 yard line). So "head in a vice" imaging will be an issue for us." There is .......
174: Speaker Asylum, RE: speakers in around the $8k -) $10k range to better what I currently use? (0.00)
Posted by Duke on 2015-01-21, 22:19:41 (208.98.182.143)
You might consider looking at speakers that use high-end prosound drivers. One of the things you get with good prosound drivers is superb dynamics and clarity because they will just be loafing along e .......
175: Speaker Asylum, RE: speakers for a different listening space (0.00)
Posted by Duke on 2015-01-20, 01:36:09 (208.98.182.143)
It sounds to me like the reverberant field plays an especially large role in your space, and imo that's a good thing, as the same is true of a good recital hall. So you might look at speakers that do .......
176: Speaker Asylum, RE: Pure mathematics I guess... (0.00)
Posted by Duke on 2014-12-23, 10:06:16 (208.98.182.143)
Small rooms impose a large peak-and-dip pattern on any bass source within the room. One solution is to use multiple bass sources (like four) distributed asymmetrically around the room, such that each .......
177: Speaker Asylum, RE: Allison Effect (0.00)
Posted by Duke on 2014-12-02, 17:33:19 (208.98.182.143)
"Duke discussed how room coupling produces "shelving bass boost" below the frequency at which bass reflections from the room's boundaries and the primary output of the woofer re-inforce each other. "Y .......
178: Speaker Asylum, Below 100 Hz, the elephant in the room is... (0.00)
Posted by Duke on 2014-11-30, 18:03:15 (208.98.182.143)
...the room. Rooms impose significant peak-and-dip patterns on the woofer's output. These peak-and-dip patterns are a lot more drastic than the relatively minor differences between one good speaker sy .......
179: High Efficiency Speaker Asylum, RE: How to raise the total resistance of a speaker (0.00)
Posted by Duke on 2014-11-27, 19:27:17 (208.98.182.143)
In general, the speaker's impedance is established at the design phase, and it's hard to modify it after the fact. Adding an autoformer, as has been mentioned, is one way. In theory one could also add .......
180: High Efficiency Speaker Asylum, RE: How to raise the total resistance of a speaker (0.00)
Posted by Duke on 2014-11-27, 19:07:06 (208.98.182.143)
" A higher impedance speaker won't make the most of a solid state amplifier, and as a result won't sound as good by comparison as a speaker with a lower impedance." Louder yes; better sound, maybe not .......
181: High Efficiency Speaker Asylum, RE: Looking for a wood turner (0.00)
Posted by Duke on 2014-11-27, 17:30:19 (208.98.182.143)
I'd be doing something based on the oblate spheroid, but with a wider radius mouth. Just a slightly different set of tradeoffs. I'm now thinking that being close to my wood turner would be very helpf .......
182: High Efficiency Speaker Asylum, RE: Looking for a wood turner (0.00)
Posted by Duke on 2014-11-26, 21:35:05 (208.98.182.143)
I think people liked the aesthetic of the Jazz Modules, so yes I'm looking at going in that direction. Duke .......
183: High Efficiency Speaker Asylum, RE: Looking for a wood turner (0.00)
Posted by Duke on 2014-11-26, 21:28:53 (208.98.182.143)
Thank you Rod. Eso contacted me, and I just wrote back to him a few minutes ago. Duke .......
184: High Efficiency Speaker Asylum, RE: Looking for a wood turner (0.00)
Posted by Duke on 2014-11-26, 21:26:56 (208.98.182.143)
Wow, that is really nice. That looks a lot more complicated than a round horn would be. I will give Dave Harris a holler. My speaker curiosity is piqued. What can you tell us about those two systems .......
185: High Efficiency Speaker Asylum, RE: Looking for a wood turner (0.00)
Posted by Duke on 2014-11-26, 21:22:44 (208.98.182.143)
Very interesting. Did you have the tool custom made to your specifications? That's what I figured I'd probably need to do - have a tool custom made, that would result in the profile I'm looking for. W .......
186: High Efficiency Speaker Asylum, RE: Other possible options (0.00)
Posted by Duke on 2014-11-26, 21:17:27 (208.98.182.143)
I'm looking for a custom profile, something constant-directivity that would pattern-match with its woofer in the crossover region. Duke .......
187: High Efficiency Speaker Asylum, RE: Looking for a wood turner (0.00)
Posted by Duke on 2014-11-26, 21:14:03 (208.98.182.143)
Visually I think the Jazz Modules were my most appealing design, so I'm hoping to head back in that direction. Duke .......
188: High Efficiency Speaker Asylum, RE: Looking for a wood turner (0.00)
Posted by Duke on 2014-11-23, 13:59:17 (208.98.182.143)
My most-requested models used modest-sized round horns, and imo integration with the woofer was one of the strong points. And in my experience people are less likely to "listen with their eyes" if it' .......
189: High Efficiency Speaker Asylum, RE: Looking for a wood turner (0.00)
Posted by Duke on 2014-11-23, 13:53:21 (208.98.182.143)
Not looking for anything approaching 20" horns; something more Zingali-ish. At some point might move into doing it myself but my days are pretty full already. I hate working with fiberglass and would .......
190: High Efficiency Speaker Asylum, RE: On the Trader (0.00)
Posted by Duke on 2014-11-23, 13:45:00 (208.98.182.143)
Thank you. He's in Europe, so that's less convenient, but not impossible. If I strike out here I'll get in touch with him. Duke .......
191: High Efficiency Speaker Asylum, RE: Looking for a wood turner (0.00)
Posted by Duke on 2014-11-23, 13:42:56 (208.98.182.143)
There is a wood turner in northern Utah who's not too far away, but I was hoping for someone experienced in horns. If that doesn't materialize, then I'll give him a try. Duke .......
192: High Efficiency Speaker Asylum, Looking for a wood turner (0.00)
Posted by Duke on 2014-11-23, 00:28:44 (208.98.182.143)
I'm looking for a wood turner experienced in turning round wooden horns. Any and all leads welcome. Thanks! Duke .......
193: Speaker Asylum, RE: WRONG and WRONG (0.00)
Posted by Duke on 2014-10-06, 15:45:42 (208.98.182.143)
"Re. Amplifier Damping factor related to "driver control" by a low output impedance, not Qts." I think we're almost on the same page here, but Qts IS "driver control". And amplifier output impedance m .......
194: OTL Asylum, RE: info link (0.00)
Posted by Duke on 2014-10-02, 02:35:16 (208.98.182.143)
The theoretical advantage of the configuration we use (developed by Jim Romeyn) is a longer path length to the ceiling, combined with using the cabinet itself to block any side-lobes that would get to .......
195: OTL Asylum, RE: AudioKinesis Zephrin 46 custom paint (0.00)
Posted by Duke on 2014-10-02, 02:29:19 (208.98.182.143)
The two rectangular cut-outs on the bottom-back are for the inputs, top for the front firing drivers, and bottom for the upfiring drivers. The other two rectangular cut-outs are for external resistor .......
196: OTL Asylum, RE: Transmission line? (0.00)
Posted by Duke on 2014-10-02, 02:21:20 (208.98.182.143)
The internal volume is separated into two chambers, one for the top/frontfiring woofers, and one for the bottom/rear/upfiring woofers. The upfiring woofers get more boundary reinforcement than the fr .......
197: Speaker Asylum, RE: Use a rear-firing tweeter equalized to offset the effects of the fullrange driver's beaming. (0.00)
Posted by Duke on 2014-10-02, 00:49:05 (208.98.182.143)
You'd have to run measurements on your fullrange drivers if you wanted to know what they're actually doing, as the real-world behavior of drivers often departs significantly from theory. In particular .......
198: Speaker Asylum, Room sound vs direct sound (0.00)
Posted by Duke on 2014-10-01, 19:26:30 (208.98.182.143)
"Room sound FR very different to the direct sound?" That is likely to happen with a fullrange driver, as most fullrange drivers beam significantly as they go up in frequency. Good for you, for even wo .......
199: Speaker Asylum, Series connection works fine (0.00)
Posted by Duke on 2014-10-01, 13:33:11 (208.98.182.143)
There is nothing inherently wrong with series connection of drivers, and if the net result meets the designer's goals for system integration and impedance and sensitivity, then in that case it's the r .......
200: Speaker Asylum, WRONG and WRONG (0.00)
Posted by Duke on 2014-09-30, 22:46:01 (208.98.182.143)
"A series connection also doubles the inductance that both speakers see, so - if used for woofers - or better mid-woofer - the low pass filter may be unnecessary." Wrong, because while the series indu .......
201: High Efficiency Speaker Asylum, RE: The elephant in the room is... (0.00)
Posted by Duke on 2014-08-26, 11:17:21 (208.98.182.143)
"So if you have a pair of headphones that has good base, you should be able to detect room problems when comparing them the sound of you speakers." I'm not sure even good headphones are a reliable ref .......
202: High Efficiency Speaker Asylum, RE: Global vs. Local (0.00)
Posted by Duke on 2014-08-25, 13:07:25 (208.98.182.143)
In addition to what Bill said, you have to be careful when it comes to boosting a dip. You can run out of headroom (speaker or amp) real quick if you try to EQ a deep dip. EQ can make worthwhile impro .......
203: High Efficiency Speaker Asylum, RE: The elephant in the room is... (0.00)
Posted by Duke on 2014-08-24, 20:59:58 (208.98.182.143)
"How do headphones reproduce bass with such a small distance between driver and eardrum?" I hope it doesn't sound like I'm saying rooms can't support bass energy because their dimensions are less than .......
204: High Efficiency Speaker Asylum, The elephant in the room is... (0.00)
Posted by Duke on 2014-08-24, 13:56:14 (208.98.182.143)
...the room. The room imposes peaks and dips on the frequency response far greater than the minor variations between one decent subwoofer and another. This is an acoustic problem and imo calls for an .......
205: Speaker Asylum, Three types of studio monitors for three different jobs... (0.00)
Posted by Duke on 2014-06-29, 02:39:31 (208.98.182.143)
There are three different jobs that studio monitors perform, and correspondingly three different types, though sometimes more than one job is handled by a given pair (as in the photo above, which we'l .......
206: Speaker Asylum, RE: Question (0.00)
Posted by Duke on 2014-05-16, 14:12:57 (208.98.182.143)
"All this discussion of driver polarity - the most blindingly obvious thing to me is that the sound of a seriously good system is still night and day different from live sound. Tiny effects of dispers .......
207: OTL Asylum, Thank you all for your replies (0.00)
Posted by Duke on 2014-05-13, 01:08:58 (208.98.182.143)
I appreciate everyone who's taken the time to post in this thread. I've been working on a speaker that could easily be configured for 8 ohms, but the possibility also existed of configuring it for 32 .......
208: Speaker Asylum, RE: Question (0.00)
Posted by Duke on 2014-05-10, 23:42:50 (208.98.182.143)
"...all studies have shown that there is a hierarchy of performance that listeners as a whole consider important when it come to preference. Flatness and smoothness of amplitude response and a well- c .......
209: Speaker Asylum, Shahinian (0.00)
Posted by Duke on 2014-05-10, 21:04:17 (208.98.182.143)
Hello J. Phelan, I do not mean to disrespect your work here at all (hey, you even found me!), but imo Shahinian is a legitimate specialty competitor with a non-traditional business model. As one who b .......
210: OTL Asylum, RE: Any interest in a 32 ohm speaker? (0.00)
Posted by Duke on 2014-05-10, 20:12:28 (208.98.182.143)
"The S-30 surely likes a 16 ohm load." Yes it does! I've done four Rocky Mountain shows with the S-30 driving 16-ohm speakers, and imo three of those were my top three best-sounding rooms (the other .......
211: Speaker Asylum, Good question! (0.00)
Posted by Duke on 2014-05-10, 14:38:27 (208.98.182.143)
You asked: "Regarding your own speaker designs, you seem to be saying that smoothness of off-axis midrange response is not necessarily dependent on the physical characteristics (reflective, absorptive .......
212: Speaker Asylum, Good point! (0.00)
Posted by Duke on 2014-05-10, 03:30:16 (208.98.182.143)
The ability to adjust the speaker to the room is imo quite valuable. My designs usually incorporate user-variable port tuning to help tailor the bottom end to the room acoustics, and user-adjustable " .......
213: OTL Asylum, RE: I've been using... (0.00)
Posted by Duke on 2014-05-07, 16:32:05 (208.98.182.143)
Nice combination! And thanks for letting me know what impedance setting works best with your MA1 + Zero + Ulysses system. Very interesting that such a high impedance is what you've found to work the b .......
214: OTL Asylum, RE: output impedance (0.00)
Posted by Duke on 2014-05-07, 15:29:58 (208.98.182.143)
Having designed speakers on Ralph's amps, my measurements are consistent with his claims for output impedance. For instance I can look at the bass response curves with a high-damping-factor solid stat .......
215: Speaker Asylum, RE: But... (0.00)
Posted by Duke on 2014-05-07, 15:22:12 (208.98.182.143)
Amlifier + speaker + room = system within a system Since the room is the most expensive component, it makes sense to choose amplifier + speaker to match the room. Amplifiers play a role in system dyn .......
216: General Asylum, Disagee in part (0.00)
Posted by Duke on 2014-05-07, 02:00:14 (208.98.182.143)
"Secondly the amplifier damping factor is gone in series wiring." Hello Ole, Sorry my friend but I must disagree. What you said is widely believed, but it is not true. If it were true, then we would .......
217: Speaker Asylum, RE: Agree... (0.00)
Posted by Duke on 2014-05-06, 23:42:06 (208.98.182.143)
What works against dynamic contrast is compression, primarily thermal compression. As a general rule of thumb (based on looking at published data), thermal compression is usually negligible (less than .......
218: Speaker Asylum, RE: I do, and it's part of the design (0.00)
Posted by Duke on 2014-05-06, 20:11:58 (208.98.182.143)
Yep, that's the same J.R.... my partner in high audio crimes and sonic misdemeanors. .......
219: High Efficiency Speaker Asylum, RE: "Generic" enclosure for 18inch driver (0.00)
Posted by Duke on 2014-05-05, 12:07:40 (208.98.182.143)
Eyeballing the Big Ben's cabinet, imo there's no way it's both 97 dB efficient and -6 dB at 25 Hz. I build bass cabs so I have a decent feel for what to expect. My guess is that the SWR cab is -3 dB i .......
220: Speaker Asylum, RE: I do, and it's part of the design (0.00)
Posted by Duke on 2014-05-05, 10:03:35 (208.98.182.143)
Good catch - I did mean 45 degrees - thanks! I fixed it in the original. I'd forgotten you're a DIYer... anyway, very cool! Be careful though, it's a slippery slope... I like your creative way to get .......
221: OTL Asylum, RE: I've been using... (0.00)
Posted by Duke on 2014-05-04, 21:16:59 (208.98.182.143)
Thanks for posting... I went to your website, and that's a very nice lineup of companies you represent. Needless to say, I really like your taste in OTL amps!! Regarding the superiority of the impedan .......
222: Speaker Asylum, I do, and it's part of the design (0.00)
Posted by Duke on 2014-05-04, 21:04:55 (208.98.182.143)
IF ( The idea is to take advantage of the fact that the ears localize sound sources by two mechanisms: arrival time, and intensity. So with the speakers criss-crossing in front of the listening positi .......
223: OTL Asylum, Hi Lew! (0.00)
Posted by Duke on 2014-05-03, 17:16:20 (208.98.182.143)
Likewise, nice to hear from you! The design I'm contemplating would have an efficiency in the 93 dB ballpark, so even with the S-30 we'd theoretically be able hit 110 dB. Thermal power handling would .......
224: OTL Asylum, RE: Any interest in a 32 ohm speaker? (0.00)
Posted by Duke on 2014-05-03, 16:44:48 (208.98.182.143)
Well our experiences have been different, so we've come to different conclusions... like that never happens!! I will look for that difference in resonant frequency impedance bumps that you observed ne .......
225: OTL Asylum, RE: Any interest in a 32 ohm speaker? (0.00)
Posted by Duke on 2014-05-03, 13:55:13 (208.98.182.143)
"Drivers in series don't really work together." That has not been my experience. I received a Golden Ear award from Robert E. Greene of The Absolute Sound, who does extensive measurements which are no .......
226: OTL Asylum, RE: Any interest in a 32 ohm speaker? (0.00)
Posted by Duke on 2014-05-02, 15:08:31 (208.98.182.143)
I should have been more clear... I'm talking about a 32-ohm speaker system, not the individual drivers. Eminence makes a 10-inch 32 ohm bass guitar speaker that is meant to be used in multiples, wired .......
227: OTL Asylum, RE: output power (0.00)
Posted by Duke on 2014-05-02, 14:57:45 (208.98.182.143)
Thanks for the corrections and additional information! I went back and edited my original post. I had thought that the distortion would decrease, but wanted to hear it from you to be sure that was th .......
228: OTL Asylum, Any interest in a 32 ohm speaker? (0.00)
Posted by Duke on 2014-05-02, 13:45:47 (208.98.182.143)
How much interest would there be in a 32 ohm speaker? Of course it would have to meet your other criteria, whatever they may be. I'm under the impression that the S-30 would deliver roughly double it .......
229: High Efficiency Speaker Asylum, RE: Correct (0.00)
Posted by Duke on 2014-03-22, 15:13:43 (208.98.182.143)
I'm using Celestion in several models these days - good call!! Their polymer diaphragm models are magnificent imo and ime. Every one I've tried has worked well, so I think you're in good shape just to .......
230: High Efficiency Speaker Asylum, Correct (0.00)
Posted by Duke on 2014-03-22, 02:09:19 (208.98.182.143)
The compression driver is the Beyma CP-385Nd. I went through a lot of compression drivers first, and that was the best I could find at the time for that application. Since then a couple of drivers hav .......
231: High Efficiency Speaker Asylum, RE: Well ... these sound amazing even on Youtube ! (0.00)
Posted by Duke on 2014-03-22, 01:47:21 (208.98.182.143)
Thanks! The manufacturer of that waveguide is DDS, and the model is ENG 1-90, available from US Speaker. I believe it was designed by Mark Engebretson, now with QSC. If you shoot me an e-mail, I'll te .......
232: High Efficiency Speaker Asylum, 30 dB peaks (0.00)
Posted by Duke on 2014-03-06, 16:50:05 (208.98.182.143)
At the link below you'll find an article about a demonstration where program material (a Ricky Lee Jones CD) was apparently exhibiting peaks a good 30 dB above the average. I don't know how common 30 .......
233: High Efficiency Speaker Asylum, RE: Lowther Speakers (0.00)
Posted by Duke on 2014-03-05, 22:36:18 (208.98.182.143)
If you're listening to high quality recordings that have peaks 20 dB above the average, the ability to hit 105 dB (ignoring the effects of thermal compression) implies an average SPL of 85 dB. Whether .......
234: Speaker Asylum, RE: ROCK (0.00)
Posted by Duke on 2013-12-18, 22:24:26 (208.98.182.143)
I once built a prototype bass cab that had a deliberately roller-coaster frequency response curve, tailored so that its frequency response would complement the typical response of an electric guitar c .......
235: Speaker Asylum, RE: Seal box volume for double bass (0.00)
Posted by Duke on 2013-12-15, 00:07:38 (208.98.182.143)
I design bass cabs that have done fairly well among double bass players (google "audiokinesis thunderchild"; in particular the 112 version with the "acoustic friendly" option). Just to let you know th .......
236: Speaker Asylum, RE: Ping Duke (0.00)
Posted by Duke on 2013-11-19, 01:14:43 (208.98.182.143)
I was referring to custom woofers that some manufacturers use in dynamic dipole speakers. They are characterized by high Qes and long x-max. Acoustic Elegance makes some off-the-shelf dipole woofers. .......
237: Speaker Asylum, RE: Opinions on bowl/ cup shaped drivers please? (0.00)
Posted by Duke on 2013-11-19, 01:04:07 (208.98.182.143)
A cone in breakup has better dispersion than a cone that remains a rigid piston, so it's a matter of picking your poison. A fixed "phase plug" (more properly pole-piece extension) done right will impr .......
238: High Efficiency Speaker Asylum, RE: How can i know that an horn is badly designed ? (0.00)
Posted by Duke on 2013-11-16, 01:45:14 (208.98.182.143)
The horn in the image is a Semi-Elliptical Oblate Spheroid, or SEOS, waveguide, manufactured by or for DIY Sound Group, by and for hard-core DIY speaker geeks, link below. I use it in one of my speake .......
239: Speaker Asylum, Ha! Glad you liked it! (0.00)
Posted by Duke on 2013-11-16, 01:36:14 (208.98.182.143)
If I'm dumb enough to still try to build speakers for what's left of the middle class, I can't afford to take myself too seriously! Duke .......
240: Speaker Asylum, I haven't modelled them but... (0.00)
Posted by Duke on 2013-11-16, 01:31:13 (208.98.182.143)
...remember that their recommended placement gives them the benefit of very generous boundary reinforcement in the low end. If tuned with such placement in mind, a modest size mid-efficiency speaker c .......
241: Speaker Asylum, RE: very room friendly loudspeaker (0.00)
Posted by Duke on 2013-11-16, 01:26:49 (208.98.182.143)
I'm definitely a fan of polydirectionals done well, to use Richard Shahinian's term, but I expand the definition to include dipoles and bipoles. In my opinion audiophile folklore has not caught up to .......
242: High Efficiency Speaker Asylum, RE: How can i know that an horn is badly designed ? (0.00)
Posted by Duke on 2013-11-15, 18:12:14 (208.98.182.143)
Imo horns that rely on diffraction to get good uniform coverage are more likely to sound bad because diffraction tends to sound harsh at high volume levels (the ear has a non-linear response to what i .......
243: Speaker Asylum, RE: very room friendly loudspeaker (0.00)
Posted by Duke on 2013-11-15, 17:51:38 (208.98.182.143)
I don't know whether Jim Romeyn's patent will be granted or not, so we're keeping some of what we're doing under our hats for now, because if the patent application is denied, all we have left to prot .......
244: Speaker Asylum, RE: very room friendly loudspeaker (0.00)
Posted by Duke on 2013-11-15, 17:03:15 (208.98.182.143)
Thank you very much, Jim! The LCS concept is totally the invention of Jim Romeyn, and imo it's a significant improvement over my controlled-pattern offset bipole (which did play a role in the unfoldi .......
245: Speaker Asylum, Redneck Mothers (0.00)
Posted by Duke on 2013-10-23, 18:58:03 (208.98.182.143)
A few years ago I designed a speaker specifically for up against the wall placement, to be called the "RM Monitor", with the "RM" standing for... you guess it! I never went into production with the RM .......
246: Speaker Asylum, RE: Answers... (0.00)
Posted by Duke on 2013-10-17, 23:53:05 (208.98.182.143)
I love you too... ah, strictly in a manly sort of way, of course... Duke .......
247: Speaker Asylum, RE: Thanks again ... very interesting indeed. (0.00)
Posted by Duke on 2013-10-17, 23:01:26 (208.98.182.143)
Thank you for being so open-minded, beppe! I realize that what I'm doing goes against conventional wisdom, and so many people will naturally resist & dismiss, but you are at least open to the possibil .......
248: Speaker Asylum, RE: Sorry i do not understand ... the recording was stereo ? (0.00)
Posted by Duke on 2013-10-16, 15:58:11 (208.98.182.143)
Genungo is correct, the signal was full-range stereo, and all speakers were full-range, tailored for their specific roles. We had them wired in series because our amp would rather see a 16 ohm load in .......
249: Speaker Asylum, Reflections are done wrong in most rooms/systems (0.00)
Posted by Duke on 2013-10-16, 15:09:51 (208.98.182.143)
If the bulk of the first reflections arrive too early (which is almost always the case), they tend to be detrimental. If the reverberant energy is not spectrally correct, it tends to be detrimental. B .......
250: Speaker Asylum, RE: agreed but.... (0.00)
Posted by Duke on 2013-10-15, 14:00:08 (208.98.182.143)
"The soundstage is awesome for one main reason....it's setup in a small clearing at the end of a semi-wooded lot in the middle of nowhere PA. A completely naturaly diffused environment." So... you hav .......
251: Speaker Asylum, RE: Answers... (0.00)
Posted by Duke on 2013-10-15, 12:40:55 (208.98.182.143)
Good question. Imo the best radiation pattern in a single speaker is the big SoundLabs, with the older-style 90-degree pattern panels. They give us essentially 90 degrees up and down the spectrum, fro .......
252: Speaker Asylum, RE: Possible that the reverberant field plays a key role (0.00)
Posted by Duke on 2013-10-15, 10:04:54 (208.98.182.143)
"Anyway, the concept of putting more HF energy into the reverberant field is not new. Heck, even I, as a moron, have had my speakers tilted back/up since forever, for that exact reason." From a fellow .......
253: Speaker Asylum, Possible that the reverberant field plays a key role (0.00)
Posted by Duke on 2013-10-14, 19:39:01 (208.98.182.143)
I've never set out to design a system that "images well", as I'm much more interested in natural timbre. However one of the online comments posted a couple of days ago by Audio Circle RMAF reviewer te .......
254: Speaker Asylum, RE: I agree, but (0.00)
Posted by Duke on 2013-09-22, 18:35:57 (208.98.182.143)
That small room will have significant modal issues from ballpark 250 Hz on down, which is well within the passband of even small speaker systems. In fact, the modal behavior of small rooms is audibly .......
255: Speaker Asylum, If you really want to get the room right... (0.00)
Posted by Duke on 2013-09-21, 20:37:34 (208.98.182.143)
"I would be prepared to add whatever room treatments where necessary to maximize the rooms potential." I strongly suggest you engage a professional to help you get the room treatment right. I've worke .......
256: Speaker Asylum, My first commercial effort... (0.00)
Posted by Duke on 2013-09-18, 22:09:15 (208.98.182.143)
...was philosphically similar to what you describe. It used an 8" wideband driver from about 150 Hz on up, augmented on top with a tweeter, and down low with a built-in powered woofer section. You can .......
257: Speaker Asylum, "Is it all because of aesthetics?" A lot of it is... (0.00)
Posted by Duke on 2013-08-05, 09:10:03 (208.98.182.143)
Aesthetics = sales, and more people want slim speakers even if there's a sonic penalty (which they are often unaware of). The demise of brick 'n mortars plays a role too, I think. Fewer opportunities .......
258: Speaker Asylum, RE: stick with FOREVER speakers (LONG) (0.00)
Posted by Duke on 2013-07-31, 23:35:27 (208.98.182.143)
Tanglewood I know of... and Julliard I know of... but what's this uber-exclusive "blah blah blah" conservatory of which you speak?? Seriously, I hope you write professionally. I've never heard a bette .......
259: Speaker Asylum, stick with FOREVER speakers (0.00)
Posted by Duke on 2013-07-31, 19:08:00 (208.98.182.143)
You mentioned that you're a symphonic musician. That implies a vow of poverty, and the curse of unforgiving ears. Used Harbeths make a lot of sense in that context. I used to be a Harbeth dealer, and .......
260: High Efficiency Speaker Asylum, RE: A Loud Hifi for a crowd, (0.00)
Posted by Duke on 2013-07-30, 15:20:13 (208.98.182.143)
Ha! Good job of checking up on me! Looks like I'm way off on the time! It's a memory from forty years ago. But the distance is in the 30-mile ballpark (outskirts of Clinton, Louisiana, if you want to .......
261: High Efficiency Speaker Asylum, RE: A Loud Hifi for a crowd, (0.00)
Posted by Duke on 2013-07-28, 04:28:50 (208.98.182.143)
Congratulations, Tom!! Tiger Stadium can be a loud place. I used to live out in the country nearly thirty miles from Tiger Stadium, as the crow flies. If the weather conditions were right, we could wa .......
262: Speaker Asylum, Ty Lashbrook's designs are well thought-out and high value (0.00)
Posted by Duke on 2013-07-21, 21:20:47 (208.98.182.143)
The only thing I don't like about Tyler Acoustics speakers is having to compete against them. Take a look at Ty's Pro Dynamics line, link below. See those MHM designs? That is the RIGHT way to do it! .......
263: Speaker Asylum, RE: Also........ (0.00)
Posted by Duke on 2013-07-21, 19:56:25 (208.98.182.143)
Yes, something that is not obvious is how the supertweeter and tweeter's responses combine. We can easily get undulations in the net frequency response of +4/-12 dB (or more) as the supertweeter's out .......
264: Speaker Asylum, RE: My vote Aerial 7T (0.00)
Posted by Duke on 2013-07-04, 05:12:13 (208.98.182.143)
The Arial 7T is a fine speaker, but imo is not a particularly great match for the Atma-Sphere M-60. Into the 7T's 4-ohm load, the M-60 is a 45-watt amp, and the 7T's voltage sensitivity is about 87 dB .......
265: High Efficiency Speaker Asylum, ...... (0.00)
Posted by Duke on 2013-06-26, 12:05:44 (208.98.182.143)
Dangit! Shoulda known. Thanks just the same. Duke .......
266: High Efficiency Speaker Asylum, ???? (0.00)
Posted by Duke on 2013-06-25, 16:45:41 (208.98.182.143)
"...SEAS alnico 12in woofers." If that woofer's identity is a trade secret I certainly understand, but if not, I'd love to know! Thanks, Duke .......
267: High Efficiency Speaker Asylum, RE: The best 1" compression driver (0.00)
Posted by Duke on 2013-06-16, 13:20:48 (208.98.182.143)
Generally the shorter the distance between the phase plug and the driver exit, the wider the exit angle. Of course the diameter of the phase plug's narrow end plays a role in the internal geometry as .......
268: High Efficiency Speaker Asylum, RE: The best 1" compression driver (0.00)
Posted by Duke on 2013-06-16, 08:39:49 (208.98.182.143)
The D1400 has the same internal geometry issue as the TAD, namely a long, narrow-angle internal passageway between phase plug and exit, resulting in a significant discontinuity where the exit meets th .......
269: High Efficiency Speaker Asylum, RE: The best, cost no object, 1" compression driver for an OSWG (0.00)
Posted by Duke on 2013-06-15, 23:19:53 (208.98.182.143)
The TAD 2001 would be a poor choice because its internal geometry (long, narrow-angle internal "snout") does not transition well to the relatively wide-angle throat of the oblate spheroid waveguide. .......
270: General Asylum, Story of a Marine (0.00)
Posted by Duke on 2013-06-14, 18:40:52 (208.98.182.143)
This picture was taken some time before 1966, the year my step-father was in a helicopter crash that left his face and hands badly burned. He was somewhat camera-shy after that. My step-father was a .......
271: Speaker Asylum, RE: Speakers for Atma-Sphere M-60s (0.00)
Posted by Duke on 2013-06-02, 18:40:03 (208.98.182.143)
Hi Jeff, Thanks for the additional information. I was kinda hoping that opening was behind the speakers, as that would have made it a little easier to use bipolars. I see in another post that you have .......
272: OTL Asylum, RE: Please list speakers that work well with..... (0.00)
Posted by Duke on 2013-06-02, 00:48:21 (208.98.182.143)
I like your choice of amplifier! I have used the S-30 at audio shows more often than any other amp. Had a hard time thinking of additions to Ralph's list. Obviously, he's in a really good position to .......
273: High Efficiency Speaker Asylum, RE: Ahhhh know (0.00)
Posted by Duke on 2013-06-01, 22:32:14 (208.98.182.143)
Ahhh... that's my signature line slash disclaimer! Sorry about that - I'm partially an "M" and partially a "D", and figure I should warn people accordingly. I forgot to sign my name at the end of my p .......
274: Speaker Asylum, RE: Speakers for Atma-Sphere M-60s (0.00)
Posted by Duke on 2013-06-01, 22:29:50 (208.98.182.143)
Yes, I design specifically for compatibility with Atma-Sphere amps, but take steps to maintain compatibility with solid state amps too, by keeing the impedance curve benign. The smoother the impedance .......
275: High Efficiency Speaker Asylum, Ahhhh know (0.00)
Posted by Duke on 2013-05-31, 20:19:38 (208.98.182.143)
it's only rock 'n roll but ah lie kit In my old hometown (New Orleans), I was friends with a fellow audiophile named Doak. We were both on the mailing list for a local high-end audio store, who got us .......
276: High Efficiency Speaker Asylum, 'scuse me? (0.00)
Posted by Duke on 2013-05-31, 02:49:06 (208.98.182.143)
I don't remember posting any 15" coaxials for sale. Or were you talking to someone else? Duke .......
277: High Efficiency Speaker Asylum, RE: Edgarhorn website died 4/27/13 (0.00)
Posted by Duke on 2013-04-29, 02:37:27 (208.98.182.143)
Hi Bruce, Lori and I certainly wish you the very best. Thanks for all you have contributed to high end audio. Thanks for setting the bar so high so well. I'm close friends with Nick Ferber, and as yo .......
278: Speaker Asylum, What works in prosound may not be best for our smaller rooms (0.00)
Posted by Duke on 2013-04-24, 18:35:33 (208.98.182.143)
The "power alley" paradigm assumes that the direct sound dominates, which is true outdoors, and may be largely true in some venues, but it is certainly not true in a typical home listening room. In th .......
279: Speaker Asylum, Toole on reflections and speech intelligiblility in small rooms (0.00)
Posted by Duke on 2013-04-15, 01:58:18 (208.98.182.143)
Hi Tom, In chapter 10 of "Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and Rooms", Floyd Toole makes the highly counter-intuitive claim that, in "small" rooms (as opposed to l .......
280: Speaker Asylum, RE: Passive Crossover Question (0.00)
Posted by Duke on 2013-04-11, 17:06:40 (208.98.182.143)
I would recommend using a capacitor and series resistance only (no parallel resistance), to minimize the impedance drop. It does not matter whether your series resistor comes before the capacitor or a .......
281: Speaker Asylum, Since you included polydirectionals... (0.00)
Posted by Duke on 2013-04-03, 21:07:11 (208.98.182.143)
I currently build polydirectional speakers in two different configurations: Controlled-pattern offset bipole, and controlled-pattern twisted bipole. I believe these offer some advantages over true omn .......
282: Speaker Asylum, ...half the lies they tell about me aren't true... (0.00)
Posted by Duke on 2013-03-23, 19:56:59 (208.98.182.143)
...in theory at least. I hope you realize that I wasn't arguing with your specific recommendations, only with a supporting statement you made, to which I believe there are exceptions. You asked what .......
283: Speaker Asylum, "You can argue with me..." (0.00)
Posted by Duke on 2013-03-23, 17:10:11 (208.98.182.143)
Hi John, I hope you don't mind if I take you up on your invitation! Your wrote: "What makes [the ATC SCM 19] attractive at least to me, is that it is a (pardon me) SEALED BOX DESIGN, and therefore it .......
284: Speaker Asylum, RE: Ms Willkayakforfood asked a valid question ... (0.00)
Posted by Duke on 2013-03-19, 19:26:34 (208.98.182.143)
Horizontally offset tweeters spread out the edge diffraction so that it's not all happening at the same time. I'm not sure whether this is beneficial or detrimental for imaging, but it's probably bene .......
285: High Efficiency Speaker Asylum, RE: No problem with the mids. It's up top that causes issues. (0.00)
Posted by Duke on 2013-03-19, 17:24:56 (208.98.182.143)
Imo it's a good idea to use drivers that go together well, including in the impedance domain. It sounds to me like you have two great drivers that do not work well together. I think that's where the m .......
286: Speaker Asylum, Omnis and reflection path lengths (0.00)
Posted by Duke on 2013-03-18, 00:31:00 (208.98.182.143)
Omnis and other polydirectionals seem to be at their best when set up to allow a significant time delay between the first-arrival sound and the onset of the additional reverberant energy. If the extra .......
287: Speaker Asylum, RE: another technical question.. (0.00)
Posted by Duke on 2013-03-18, 00:05:14 (208.98.182.143)
The signal that goes into the hi-level inputs goes through what's called a "voltage divider network" and is converted into a nice friendly lo-level signal. It then goes through the subwoofer amp's cir .......
288: Speaker Asylum, RE: Done, though (0.00)
Posted by Duke on 2013-03-17, 19:53:19 (208.98.182.143)
Thank you, Badman! Glad the offset bipolar concept is working for you! And I see no reason not to explore variations on the theme, as you are doing. For anyone wondering what we're talking about, it' .......
289: Speaker Asylum, Dif'rent strokes... and home theater application (0.00)
Posted by Duke on 2013-03-16, 13:24:56 (208.98.182.143)
"I can sit 2 feet to the left of my left speaker (Gallo Ref. 3.10) and *clearly* hear the right speaker as well as a credible soundstage." Yup! I'm a Gallo dealer and have heard what you describe from .......
290: Speaker Asylum, RE: Very interesting, but... (0.00)
Posted by Duke on 2013-03-15, 17:52:39 (208.98.182.143)
With my speakers, best imaging for one is with both speakers aimed right straight at the listener's ears, with the listener in the center of the sweet spot. So that would be less than 45 degrees of to .......
291: Speaker Asylum, RE: Well stated, and Hi Duke- (0.00)
Posted by Duke on 2013-03-15, 10:45:22 (208.98.182.143)
Nope I don't see your e-mail - could you re-send? I did some experimenting but not much. Thanks! Duke .......
292: Speaker Asylum, 45 degrees (0.00)
Posted by Duke on 2013-03-14, 23:34:02 (208.98.182.143)
I design my speakers to be toed in about 45 degrees, such that the axes criss-cross in front of the listening position. If the speakers have a roughly 90 degree (-6 dB limits) radiation pattern in the .......
293: Speaker Asylum, RE: What's the Speaker for A Crowded Over Damped Family Room? (0.00)
Posted by Duke on 2013-02-14, 14:39:18 (208.98.182.143)
For an overdamped room, you might want to be able to adjust the high frequency balance, as short wavelengths are going to be absorbed more efficiently than longer ones. Most speakers will probably sta .......
294: Speaker Asylum, Flat isn't really flat (0.00)
Posted by Duke on 2013-02-12, 23:28:53 (208.98.182.143)
No speaker that I am aware of has a uniform enough radiation pattern that it can be flat both on-axis and off-axis (which dominates the reverberant field) at the same time. No, not even the MBLs - the .......
295: High Efficiency Speaker Asylum, RE: Are Altec Valencias suitable for smaller rooms? (0.00)
Posted by Duke on 2013-02-07, 03:08:51 (208.98.182.143)
If the Valencia's need a 30-foot deep room to sound right, it might be more cost-effective to seek out a different speaker rather than knocking down walls to satisfy the Valencias... Seriously, the Mo .......
296: Speaker Asylum, RE: "Consider that a grand piano sounds better in a "live" room than in a dead one" (0.00)
Posted by Duke on 2013-01-30, 13:32:18 (208.98.182.203)
If reflections were so bad, we'd all be striving for quasi-anechoic lisltening rooms. The recording engineers usually expect you to listen in a moderately reverberant room, so most recordings don't h .......
297: Speaker Asylum, RE: Yiu need to listen in the near field... (0.00)
Posted by Duke on 2013-01-30, 01:15:00 (208.98.182.203)
If the speakers have spectrally-correct off-axis response (possible with good radiation pattern control), the relatively strong reverberant field in his room may be quite beneficial. Consider that a g .......
298: Speaker Asylum, RE: Jazz speaker (0.00)
Posted by Duke on 2013-01-29, 20:58:25 (208.98.182.203)
"The only solution is to pry out the drivers and the crossover of the favorite speaker, pack it in the suitcase and bring and build enclosure here." That's actually not a bad idea. Well, except that i .......
299: Speaker Asylum, RE: Will a Woofer with two coils benefit from two separate amps (0.00)
Posted by Duke on 2012-12-01, 12:58:12 (208.98.182.203)
Unless the woofer really is designed for both coils to get a different signal, you run the risk of mechanical failure by using it that way. If you have two different signals fighting one another over .......
300: High Efficiency Speaker Asylum, RE: DIY speaker recommendations (0.00)
Posted by Duke on 2012-10-26, 01:19:56 (208.98.182.203)
PiSpeakers offers very well-designed high-efficiency speakers as plans, kits, or finished products. GedLee (Earl Geddes) offers very well-designed kits and finished speakers as well, though his are d .......
301: High Efficiency Speaker Asylum, Blow-resistant speakers (0.00)
Posted by Duke on 2012-08-28, 16:40:47 (208.98.182.203)
You have several designers/manufacturers of serious high-output speakers right here in this thread: Kloss, eso, and Bill Fitzmaurice. Sorry if I left anyone out. I'm also a fan of PiSpeakers, suggeste .......
302: Speaker Asylum, Omega man (0.00)
Posted by Duke on 2012-08-27, 17:17:33 (208.98.182.203)
You might consider contacting Louis Chochos of Omega Loudspeakers. He builds reasonably-priced (for high-end audio), very high quality single-driver point-source speakers. Explain your needs to him, a .......
303: Speaker Asylum, insights (0.00)
Posted by Duke on 2012-07-14, 11:21:17 (208.98.183.169)
Well yes, if the room is absorptive enough that there is little energy delivered to the ears via reflections, then obviously the direct sound matters the most. But unless you have a highly damped room .......
304: Speaker Asylum, I agree with Thorsten (0.00)
Posted by Duke on 2012-07-12, 21:30:27 (208.98.183.169)
The on-axis response only predicts the spectral balance of the first-arrival sound that reaches your ears. The power response predicts the spectal balance of the reverberant energy also, and I agree w .......
305: Speaker Asylum, RE: Your big speakers are fairly unusual two-way designs... (0.00)
Posted by Duke on 2012-07-01, 19:03:58 (208.98.183.169)
"Your big speakers are fairly unusual two-way designs... that might work well in a small room, as you say. But many other big speakers are 3 or 4-way designs that won't integrate properly unless the l .......
306: High Efficiency Speaker Asylum, RE: Faital HF Drivers (0.00)
Posted by Duke on 2012-07-01, 01:46:42 (208.98.183.169)
Both the frequency response curve and impedance curve of the HF200 indicate a significant resonance around 15 kHz. Of the two, for a high fidelity application I'd go with the HF204 and just goose the .......
307: Speaker Asylum, RE: Planars vs. Horns Discussion (0.00)
Posted by Duke on 2012-07-01, 01:29:25 (208.98.183.169)
The dipole radiation pattern of a well-set-up planar is a distinct advantage in my opinion, as it adds spectrally-correct reverberant energy that arrives after a pretty good time delay ("well-set-up" .......
308: Speaker Asylum, RE: Big speakers + small room = Bad? (0.00)
Posted by Duke on 2012-07-01, 00:38:10 (208.98.183.169)
Fairly tight radiation pattern control well down into the midrange is arguably more beneficial in a small room than in a big room, as it allows you to aim the speakers so as to maximize the time inter .......
309: High Efficiency Speaker Asylum, RE: Horn tweeter ID needed (see photos at links) (0.00)
Posted by Duke on 2012-05-02, 18:07:14 (208.98.183.169)
The gold looks like spray paint to me. Maybe it's supposed to be camouflage. If those are old Motorolla piezos they probably suck less than most of their kind, and who knows, maybe some spray paint on .......
310: High Efficiency Speaker Asylum, RE: Midbass horn size confusion (0.00)
Posted by Duke on 2012-04-18, 14:20:52 (208.98.183.169)
Always enjoy it when you take the time to explain things, Bruce. And I agree with you about Nick Ferber's work - he's really good at what he does. Duke .......
311: General Asylum, No. (no text) (0.00)
Posted by Duke on 2012-03-18, 00:43:58 (208.98.183.169)
.......
312: Speaker Asylum, RE: Blown resistor (0.00)
Posted by Duke on 2012-03-08, 14:15:56 (208.98.183.169)
" I moved them into a much larger room with 600wpc Pass monoblocks on them and it was just too much." You might consider replacing your 50 ohm, 50 watt resistor with two 100 ohm, 50 watt resistors in .......
313: High Efficiency Speaker Asylum, Wonderful post! (0.00)
Posted by Duke on 2012-02-24, 14:53:41 (208.98.183.169)
I love it, man! Thanks for sharing. Duke .......
314: High Efficiency Speaker Asylum, RE: cabinet designs for 15" coaxials (0.00)
Posted by Duke on 2012-02-10, 01:07:16 (208.98.183.169)
Those measurements look a little strange to me. Re(series) should be about four times Re(parallel), and such is not the case. Also, there should not be so much change in Qes. My guess is that some err .......
315: High Efficiency Speaker Asylum, RE: Maybe. (0.00)
Posted by Duke on 2012-02-04, 12:17:38 (208.98.183.169)
Ha! You got me! Duke .......
316: High Efficiency Speaker Asylum, RE: I Need Your Help With A Crossover Problem (0.00)
Posted by Duke on 2012-02-03, 17:56:59 (208.98.183.169)
What works in the real world isn't necessarily what a textbook calculation says. My guess is the capacitor is being used to "pad back" that very high efficiency supertweeter. I'm assuming the FE208ESR .......
317: High Efficiency Speaker Asylum, Maybe. (0.00)
Posted by Duke on 2012-02-03, 17:47:42 (208.98.183.169)
We need to see the horizontal and vertical scales correctly labelled so we can tell what frequency we're looking at, and how much variation we're seeing. Also it would be nice to have some information .......
318: General Asylum, RE: Sad, actually. (0.00)
Posted by Duke on 2012-01-31, 20:18:40 (208.98.183.169)
As a dealer, Audiogon was a key part of my business; probably half of my customers needed to sell something they currently owned in order to afford the new thing they wanted from me. Audiogon made tha .......
319: General Asylum, RE: A'gon security in the good old days/goodbye to Arnie (0.00)
Posted by Duke on 2012-01-31, 20:09:24 (208.98.183.169)
A couple years ago someone apparently hacked my Audiogon account and accessed it from a foreign web address without me knowing about it. The first I heard of it was, someone from Audiogon called me up .......
320: Speaker Asylum, RE: best 10" woofer (0.00)
Posted by Duke on 2012-01-12, 16:48:29 (208.98.183.169)
I second Badman's suggesion of Acoustic Elegance; no firsthand experience with the others he mentions but would trust his opinions. Consider the possibility that the holy grail is not a combination of .......
321: Speaker Asylum, RE: Your Thoughts - Tweet and Midwoof for MTM (0.00)
Posted by Duke on 2011-11-30, 00:43:32 (208.98.183.169)
The difference in vertical pattern width at the crossover frequency was theoretically comparable to the difference between a 1" dome tweeter and a single 5" cone, which would be a lot better than a no .......
322: Speaker Asylum, RE: Your Thoughts - Tweet and Midwoof for MTM (0.00)
Posted by Duke on 2011-11-29, 23:34:15 (208.98.183.169)
Imo the better alternative to MTM is the "MHM" format, where the radiation pattern of the horn tweet roughly matches the radiation pattern of the woofers at the crossover frequency. Tyler Acoustics us .......
323: Speaker Asylum, An unexpected result (0.00)
Posted by Duke on 2011-11-17, 11:33:56 (208.98.183.169)
Once upon a time I conducted an informal but controlled blind listening comparison between a fullrange driver speaker and a two-way with a 4th order (net acoustic slope) passive crossover. The listene .......
324: Speaker Asylum, Some 'stats do have constant directivity (0.00)
Posted by Duke on 2011-11-16, 20:21:37 (208.98.183.169)
The SoundLabs with their segmented-curved panel do a better job at "constant directivity" than most horn or waveguide speakers, including my own. Each fullrange vertical facet is maybe 5" wide, and i .......
325: Speaker Asylum, RE: Good points (0.00)
Posted by Duke on 2011-11-16, 19:59:50 (208.98.183.169)
Horns roll off fairly rapidly below their cutoff frequency, and so generally aren't good candidates for first order crossovers because they're often rolling off at second order or more before a crosso .......
326: Speaker Asylum, Good points (0.00)
Posted by Duke on 2011-11-14, 20:54:35 (208.98.183.169)
"I put that down to... their exemplary dispersion characteristics which is basically a smooth transition from omni-directional bass which narrows to 90deg conical at crossover frequency and stays like .......
327: High Efficiency Speaker Asylum, RE: "90 to 900 Hz" (0.00)
Posted by Duke on 2011-11-10, 13:08:06 (208.98.183.169)
I agree with Bill Fitzmaurice, you need to go a whole lot higher than 900 Hz on the top end if decent quality sound is one of your goals. A mere 900 Hz top end will sound dull and lifeless, and voices .......
328: High Efficiency Speaker Asylum, "90 to 900 Hz" (0.00)
Posted by Duke on 2011-11-10, 00:40:43 (208.98.183.169)
How did you come to the conclusion that 90 Hz to 900 Hz is all you need? Duke .......
329: High Efficiency Speaker Asylum, RE: How to integrating a tweeter with this horn (0.00)
Posted by Duke on 2011-09-29, 20:25:45 (208.98.183.169)
Here is what I would try; note that I am not an expert on fullrange drivers: If the fullrange driver really is fullrange on axis, but is beaming rather badly in the top octave or so, you might try a r .......
330: High Efficiency Speaker Asylum, RE: HOW TO: Constant directivity Corner speaker without horns (0.00)
Posted by Duke on 2011-09-12, 11:49:36 (208.98.183.169)
"How would you build a constant directivity corner speaker without horns?" Either use a floor-to-ceiling line array, or hire a good marketing department that is not subservient to the laws of physics. .......
331: OTL Asylum, RE: And it came to pass that there was a parting of the ways (0.00)
Posted by Duke on 2011-09-09, 22:18:16 (208.98.183.169)
THANK YOU Bill for your service to Ralph, Atma-Sphere, and its community (on both sides of the counter) over the years. We'll miss your being there, but hope to often see you here. Duke ::: TOPIC:: .......
332: High Efficiency Speaker Asylum, The alternative to horns is... (0.00)
Posted by Duke on 2011-09-07, 14:04:01 (208.98.183.169)
...better horns. For example, check out PiSpeakers. They do not have that harshness you're talking about, not at all. Duke .......
333: Planar Speaker Asylum, RE: How will Maggies sound in my new room? (0.00)
Posted by Duke on 2011-09-06, 23:06:54 (208.98.183.169)
Being dipoles with a null to the side, Maggies are less sensitive to sidewalls than most conventional speakers. So you're definitely ahead of the game... surprise, surprise. Duke .......
334: General Asylum, RE: Do sealed box woofers float? (0.00)
Posted by Duke on 2011-09-03, 21:22:10 (208.98.183.169)
I suggest you remove the woofers and fill the internal airspace with expanding foam, as that will insure they float just fine even if the MDF gets waterlogged. You have to move quickly so that you can .......
335: OTL Asylum, RE: this FAQ has been on the website for over a year. (0.00)
Posted by Duke on 2011-08-30, 15:06:07 (208.98.183.169)
Thanks for the link, Ralph. It makes no sense to me that Tre' would crusade so vehemently over whether or not "Class A2" can legitimately be called "Class A" (and duh, it's obviously a type of "Class .......
336: OTL Asylum, Uncanny resemblance in writing styles (0.00)
Posted by Duke on 2011-08-28, 22:05:37 (208.98.183.169)
Here, let me show you why I made the assumption: Tre', 8-26-11: "My main focus here is to educate people." GFL, 8-27-11: "My main focus here is to educate people." * * * Tre', 8-26-11: "I think it is .......
337: Speaker Asylum, The tailors who made those new clothes for the emperor (0.00)
Posted by Duke on 2011-08-28, 19:53:16 (208.98.183.169)
I'm wearing mine right now. So sheer you don't even know it's there. You should see the astonished looks people give me. .......
338: OTL Asylum, Is this you again Tre', using a different moniker? (0.00)
Posted by Duke on 2011-08-28, 19:46:19 (208.98.183.169)
And now we can clearly see that your agenda has nothing to do with science. Duke .......
339: Speaker Asylum, RE: Speaker Directivity (0.00)
Posted by Duke on 2011-08-27, 00:37:45 (208.98.183.169)
The directivity of a horn or cone at a given frequency depends on the specifics of that particular horn or cone. Below is a link to a spec sheet that shows polar data for a prosound woofer, so you ca .......
340: Speaker Asylum, I used to think so too, but no longer do. (0.00)
Posted by Duke on 2011-08-26, 13:17:11 (208.98.183.169)
Recently I've had some dealing with a couple of high-end recording studios. Those guys have really good ears, and are very thorough. I don't think anyone in the recording chain would voluntarily liste .......
341: Speaker Asylum, RE: Why not use active pro studio monitors in the home? (0.00)
Posted by Duke on 2011-08-25, 18:30:12 (208.98.183.169)
I've spent some time looking at the pro studio monitor market, and this is what I've found: Active speakers totally dominate the lower and middle price ranges, but among "high end" studio monitors, pa .......
342: Speaker Asylum, RE: Equipment that designers use in voicing their speakers (0.00)
Posted by Duke on 2011-08-25, 18:01:12 (208.98.183.169)
Well the main reason for showing your gear at an audio show is in hopes of impressing people with how it sounds. So in that sense it is indeed for "advertising purposes". And I don't know of any manuf .......
343: Speaker Asylum, RE: Equipment that designers use in voicing their speakers (0.00)
Posted by Duke on 2011-08-25, 17:51:31 (208.98.183.169)
Yeah, I have customers who know far more about particular match-ups than I do. But then I don't have the benefit of input from nearly as many customers as you do. You have what... hundreds? Thousands? .......
344: Speaker Asylum, RE: Sensitivity rating vs. highest output (0.00)
Posted by Duke on 2011-08-25, 00:26:25 (208.98.183.169)
My recollection is that Dynaudio made some rather impressive short-term power handling claims based on extremely short-duration high-power bursts. Typically a speaker has about 1 dB of thermal compres .......
345: Speaker Asylum, RE: Equipment that designers use in voicing their speakers (0.00)
Posted by Duke on 2011-08-24, 20:38:34 (208.98.183.169)
One time I was trying to get a speaker manufacturer to give me amplifier recommendations. They were vague and non-committal, and stuck to generalities. So I asked a different question: What amplifiers .......
346: Speaker Asylum, Role of the speakers (0.00)
Posted by Duke on 2011-08-24, 18:34:09 (208.98.183.169)
Very interesting video, genungo! Thanks for posting the link. All of the differences we hear in the various clips are due to differences in the reverberant field. Obviously the reverberant field is m .......
347: Speaker Asylum, RE: Interesting (0.00)
Posted by Duke on 2011-08-22, 15:17:26 (208.98.183.169)
"I had always thought that D'Appolito arrangements required tweeter at ear level. A narrow listening window in the vertical plane is one of the characteristics of this design." This is my understandin .......
348: Speaker Asylum, RE: Yes (0.00)
Posted by Duke on 2011-08-21, 17:01:13 (208.98.183.169)
Good points. Another possible consideration for nearfield listening is this: The ear tends to mistakenly localize high frequency sound sources as coming from a higher vertical angle than they really .......
349: High Efficiency Speaker Asylum, RE: High Efficiency woofer for 2-way system (0.00)
Posted by Duke on 2011-08-11, 19:56:11 (208.98.183.169)
In my experience most horn-based systems require substantial EQ, and I'm not sure the crossover you have in mind will provide that. No experience with that woofer. Based on its Thiele-Small parameters .......
350: Speaker Asylum, RE: ...then you're measuring with the wrong yardstick. (0.00)
Posted by Duke on 2011-08-10, 15:25:07 (208.98.183.169)
Controlled tests have shown a strong correlation between the RIGHT measurements and subjective preference (see Floyd Toole's "Sound Reproduction: The Acoustics and Psychoacoustics of Loudspeakers and .......
351: Speaker Asylum, "For instance, what's an accurate dispersion pattern for a home speaker?" (0.00)
Posted by Duke on 2011-08-10, 11:29:54 (208.98.183.169)
Thanks Tom - you pitch 'em low and to the outside, and I'll swing away! Seriously, I'm not sure what the ideal pattern for home audio would be in every room, but a reasonably uniform 90-degree pattern .......
352: Speaker Asylum, The problem with applying the "straight wire with gain" paradigm to speakers is... (0.00)
Posted by Duke on 2011-08-10, 11:14:12 (208.98.183.169)
...the energy that comes out of the speaker is radiated into three-dimensional space, rather than along a one-dimensional wire. And unfortunately the spectral balance of that energy changes with the r .......
353: Speaker Asylum, ...then you're measuring with the wrong yardstick. (0.00)
Posted by Duke on 2011-08-09, 23:44:27 (208.98.183.169)
If the yardstick by which you measure "accuracy" doesn't correlate well with subjective perception, then it is of academic interest only. In the world of high-end audio, a lot of measuring is done usi .......
354: High Efficiency Speaker Asylum, For Mongo (0.00)
Posted by Duke on 2011-08-07, 17:09:33 (208.98.183.169)
Lucky dog. I hear he's even got a Rush song dedicated to him. Duke Asylum member number 2112 .......
355: Speaker Asylum, Possible acoustic cause (0.00)
Posted by Duke on 2011-08-07, 15:46:20 (208.98.183.169)
The panels radiate as a line source, while the woofer radiates as a point source. SPL falls off more gradually with distance from a line source than from a point source (3 dB per doubling of distance .......
356: General Asylum, RE: I'm a musician and an audiophile (0.00)
Posted by Duke on 2011-07-27, 23:14:37 (208.98.183.169)
When the recession hit a couple of years ago, I looked around for a way to supplement the home audio side of my business. You see, my crystal ball predicted that demand for expensive toys was going to .......
357: High Efficiency Speaker Asylum, RE: Current mfrs of whizzerless FR/WR drivers? (0.00)
Posted by Duke on 2011-07-21, 17:47:05 (208.98.183.169)
Supravox, Fostex and Tang Band come to mind. Duke .......
358: Speaker Asylum, Thanks for catching that! (0.00)
Posted by Duke on 2011-07-18, 16:54:45 (208.98.183.169)
Some of the text was lifted from a description of a 2.5 grand speaker, and I missed that part. Duke .......
359: Speaker Asylum, Not quite triangular... (0.00)
Posted by Duke on 2011-07-18, 12:15:03 (208.98.183.169)
Thanks for the mention, mark g., but the footprint of the Prisma is more like a fairly deep rectangle with one corner generously lopped off at a 45 degree angle. This is hard to see looking at the to .......
360: Speaker Asylum, RE: PA speakers (0.00)
Posted by Duke on 2011-07-15, 02:12:07 (208.98.183.169)
"I have been told that using speakers with a higher wattage than the amp can cause the speaker to flex more and thus shorten the life of the speaker." Whoever told you that mistaken. Just don't hard- .......
361: High Efficiency Speaker Asylum, Measuring with different yardsticks (0.00)
Posted by Duke on 2011-07-13, 10:01:56 (208.98.183.169)
Some manufacturers specify the efficiency based on the most prominent midband frequency response peak, others use a broadband average, and others use the drivers' Thiele-Small parameters. For example, .......
362: High Efficiency Speaker Asylum, RE: where to crossover for a 2 way (0.00)
Posted by Duke on 2011-06-10, 22:23:02 (208.98.183.169)
In your original post, the information given indicated that the woofer could go up to 2 kHz and the horn could go down to 1.5 kHz. Thus the woofer and horn overlap between 1.5 kHz and 2 kHz, so somewh .......
363: Speaker Asylum, markup (0.00)
Posted by Duke on 2011-06-09, 19:42:15 (208.98.183.169)
"I wouldn't be surprised if a $100,000 pair of speakers can be had for 1/2 off retail right off the showroom floor. Mark up on speakers can easily be 70-80%" I've never seen dealer markup account for .......
364: High Efficiency Speaker Asylum, RE: Any other things to consider ? (0.00)
Posted by Duke on 2011-06-06, 22:22:11 (208.98.183.169)
Good points. In practice, most big cones are in some sort of breakup mode up there, and one of the effects of cone breakup is a widening of the radiation pattern. So we can usually still get good pat .......
365: High Efficiency Speaker Asylum, RE: where to crossover for a 2 way (0.00)
Posted by Duke on 2011-06-06, 00:14:46 (208.98.183.169)
You have to look at the responses and power handling of those specific drivers and see what the logical crossover point (and slope) seems to be. You try that, evaluate the results, and modify as neede .......
366: Speaker Asylum, RE: In my experience (0.00)
Posted by Duke on 2011-06-03, 13:30:22 (208.98.183.169)
A push on the cone isn't representative of what's happening up near the port tuning frequency. The helmholtz resonance acts as a phase inverter and inverts the phase of the otherwise out-of-phase rear .......
367: Speaker Asylum, RE: Are there any driver designer/manufacturers here? I have an ALNICO question. (0.00)
Posted by Duke on 2011-05-28, 00:04:12 (208.98.183.169)
I've used alnico, ferrite, neodymium, and field coil magnet drivers in various designs. In my speaker building experience (which goes back to 1979), very good drivers exist with all four types of magn .......
368: Speaker Asylum, RE: Yup (0.00)
Posted by Duke on 2011-04-30, 11:49:23 (208.98.183.169)
Thanks for letting me know, Tom! Are these the Martin Logans you've been using? Duke .......
369: Speaker Asylum, RE: Yup (0.00)
Posted by Duke on 2011-04-30, 11:48:27 (208.98.183.169)
"... with your speakers is their a formula for optimum listening distance vs distance between speakers as the angle is built in to the design?" With a roughly equilateral triangle setup, the speaker a .......
370: Speaker Asylum, RE: Always enjoy your insight (0.00)
Posted by Duke on 2011-04-29, 17:35:35 (208.98.183.169)
Well... a few years ago I demo'd the above speakers (bipolars) for a SoundLab owner. This guy had owned various model SoundLabs continuously since the late 80's. I took my speakers to his house and se .......
371: Speaker Asylum, Yup (0.00)
Posted by Duke on 2011-04-29, 15:11:18 (208.98.183.169)
All of my models are intended for severe toe-in, such that the speaker axes criss-cross in front of the listening position, and I've built this geometry into some of them. The toe-in angle in the phot .......
372: General Asylum, RE: Lone Star Audio Fest 2011 (0.00)
Posted by Duke on 2011-04-26, 03:34:03 (208.98.183.169)
Yes, Richard Gray will be there with a pair of his monoblock SET amps. Preamp will be Uriah Dailey's "Lightspeed" passive unit. Duke .......
373: General Asylum, "What speakers will you be showing?" (0.00)
Posted by Duke on 2011-04-24, 01:51:21 (208.98.183.169)
Hi Travis, I'll be showing a new model called the "Prisma" (rhymes with "BREEZE-ma"), which is an evolution of the Rhythm Prism I showed last year. At this point I'm unaware of plans for headphone-ba .......
374: General Asylum, Correction: Yes they will be! (0.00)
Posted by Duke on 2011-04-23, 05:25:44 (208.98.183.169)
From the Audio Round Table thread on the Lone Star show: "Polk Audio will be in the house showing the new LSiM and Blackstone series loudspeakers. Jaton corp is going to be providing amplification, wi .......
375: General Asylum, RE: Will Polk Audio demo their LSiM models? (0.00)
Posted by Duke on 2011-04-22, 23:59:36 (208.98.183.169)
I don't know, sorry. Maybe let them know you'd be interested, as perhaps it hasn't been decided yet. Duke .......
376: General Asylum, Lone Star Audio Fest 2011 (0.00)
Posted by Duke on 2011-04-22, 22:53:11 (208.98.183.169)
This year's Lone Star Audio Fest will be taking place May 13, 14, and 15th at the Embassy Suites Dallas Park Central hotel in Dallas, TX. The cost for exhibitors is the hotel room cost, and that's it. .......
377: High Efficiency Speaker Asylum, agree... (0.00)
Posted by Duke on 2011-04-19, 09:17:45 (208.98.183.169)
...but most people ignore radiation patterns. The subject is either inconvenient, boring, or annoying to most; taking radiation patterns into account usually complicates your system while limiting you .......
378: High Efficiency Speaker Asylum, "...the problem is not in the bandwidth." (0.00)
Posted by Duke on 2011-04-17, 23:54:24 (208.98.183.169)
Very interesting comment. Now I'm curious. Is it like the highs are there, but just don't have as much liveliness as the rest of the spectrum? Like maybe they're overdamped or something? Thanks, Duke .......
379: High Efficiency Speaker Asylum, You need to preak them in properly... (0.00)
Posted by Duke on 2011-04-14, 23:12:34 (208.98.183.169)
...let me send you my Caress of Steel album. ;^) .......
380: Speaker Asylum, Not an owner, but... (0.00)
Posted by Duke on 2011-04-13, 20:46:09 (208.98.183.169)
...sounds like a great little unit to me. Now one thing EQ cannot do is fix the low-frequency spatial variation within the room; that is, the difference in frequency response from one location to anot .......
381: Speaker Asylum, RE: Can high power burst damage speaker cones? (0.00)
Posted by Duke on 2011-04-10, 17:01:41 (208.98.183.169)
I don't know what "baning noise" is, but my previous reply still holds even if "baning noise" is a really nasty sound. "Bottoming out" is when the voice coil slams against the plate that goes across .......
382: Speaker Asylum, RE: Can high power burst damage speaker cones? (0.00)
Posted by Duke on 2011-04-10, 15:22:44 (208.98.183.169)
As long as the voice coil is neither bottoming out nor overheating, the shape of the waveform doesn't matter. Duke .......
383: Speaker Asylum, RE: Unconventional (0.00)
Posted by Duke on 2011-04-09, 15:54:01 (208.98.183.169)
Ecstatic? Well... probably so! Doing the unorthodox is an uphill battle in this industry, but on the other hand I want to do something I really believe in, so it is indeed gratifying when someone reco .......
384: Speaker Asylum, Unconventional (0.00)
Posted by Duke on 2011-04-09, 13:09:36 (208.98.183.169)
"Unconventional soundstaging and tonal balance is an acquired taste. A preference." Well yes, I suppose, but if "unconventional" is audibly more natural-sounding than "conventional", then it doesn't t .......
385: Speaker Asylum, RE: How to get good soundstaging for off-centerline listeners (0.00)
Posted by Duke on 2011-04-09, 10:52:21 (208.98.183.169)
My claim is that the type of speakers and setup I propose outperform conventional speakers for listeners outside the normal sweet spot in both soundstaging and tonal balance, and (as I hope I've shown .......
386: Speaker Asylum, How to get good soundstaging for off-centerline listeners (0.00)
Posted by Duke on 2011-04-08, 22:51:06 (208.98.183.169)
"If I'm reading this correctly, it sounds too good to be true." The setup I advocate uses speakers whose radiation pattern is about 90 degrees wide in the horizontal plane from about 1.5 kHz on up. Th .......
387: Speaker Asylum, RE: What are your listening habits? (0.00)
Posted by Duke on 2011-04-08, 19:36:46 (208.98.183.169)
Somewhat counter-intuitively, a good controlled-pattern, narrow-pattern speaker set up correctly can give very consistent tonal balance throughout the room, and even into the next room, outperforming .......
388: Speaker Asylum, A couple of answers for you, genungo... (0.00)
Posted by Duke on 2011-04-08, 16:10:25 (208.98.183.169)
"In your opinion, what is the best way to make a loudspeaker that is "room friendly"? 1) Fairly narrow, uniform pattern over as much of the spectrum as is feasible. This becomes difficult to do at lo .......
389: Speaker Asylum, RE: Controlled directivity (0.00)
Posted by Duke on 2011-04-07, 21:01:10 (208.98.183.169)
Layman, I wouldn't suggest dipoles for this situation either. Big Tannoys might well be a very good fit; one of the lines I didn't mention because of commercial affiliation uses a coaxial, albeit with .......
390: Speaker Asylum, RE: Speakers for classical in a large room. (0.00)
Posted by Duke on 2011-04-07, 19:37:16 (208.98.183.169)
Reverberant energy is going to be stronger than normal in that room because it is more reflective than most, so the reverberant energy is going to be making a larger contribution than in most rooms. T .......
391: Planar Speaker Asylum, RE: Gradient SW-63 (0.00)
Posted by Duke on 2011-03-05, 19:02:25 (208.98.186.26)
Under some conditions, this last sentence may be debatable: "Any quality 12" long-throw driver will work as a replacement if required." If you are not able EQ the frequency response of the SW-63, then .......
392: General Asylum, RE: From Al's wife, Carolyn to his AA friends. (0.00)
Posted by Duke on 2011-03-05, 16:46:08 (208.98.186.26)
Thank you, Carolyn. Very sorry for your loss. Duke .......
393: Speaker Asylum, RE: Speakers for rock music? (0.00)
Posted by Duke on 2011-03-05, 11:48:38 (208.98.186.26)
Hi Benjamin, I don't know the drivers you mentioned well enough make a well-qualified recommendation. If I had to guess off the top of my head from your list, I'd pick the Volt woofer and Audio Techno .......
394: Speaker Asylum, RE: Speakers for rock music? (0.00)
Posted by Duke on 2011-03-04, 23:57:51 (208.98.186.26)
For rock music you need good dynamic capability, but there is no point in over-spending. Identify which driver will be the limiting factor, and then there's no need to pursue excess dynamic capability .......
395: High Efficiency Speaker Asylum, Depends on what you're smoking. (0.00)
Posted by Duke on 2011-03-04, 19:09:46 (208.98.186.26)
Sorry, couldn't resist! Duke .......
396: General Asylum, RE: Usually in one or two areas but not in all (0.00)
Posted by Duke on 2011-03-04, 09:37:19 (208.98.186.26)
Hello WAJ, Thank you very much for your in-depth reply and your encouragement. I think you over-estimate my "stature" in the industry; I'm just a one-man band doin' the best I can... like so many othe .......
397: General Asylum, Usually in one or two areas but not in all (0.00)
Posted by Duke on 2011-03-02, 12:12:07 (208.98.186.26)
A good speaker has to do something well... so well that, focusing on that something, we can suspend disbelief and get totally caught up in the energy of the music. That something can be natural timbre .......
398: Speaker Asylum, RE: Where did the bass go? (0.00)
Posted by Duke on 2011-02-28, 14:31:05 (208.98.186.26)
"The only thing I can think of with the Soundlabs vs. the TSM's is the Soundlabs might have been putting out a lot of bass energy disproportional to the rest of the spectrum but in my room it balanced .......
399: High Efficiency Speaker Asylum, RE: the magic of geometry (0.00)
Posted by Duke on 2011-02-27, 18:06:07 (208.98.186.26)
I think that was the NHT model 3.3, link below. One difference is that the NHT's front baffle was toed-in at about 15 degrees, putting listeners in the normal "sweet spot" pretty close to on-axis of t .......
400: High Efficiency Speaker Asylum, the magic of geometry (0.00)
Posted by Duke on 2011-02-27, 14:12:59 (208.98.186.26)
It's not really a Model 14, just looks a bit like it might have started out as one: 12" woofer, big rectangular horn. Crams the same small-room-friendly benefits of the Model 14 into an 11" wide footp .......
401: High Efficiency Speaker Asylum, RE: For those reccomending large speakers... (0.00)
Posted by Duke on 2011-02-27, 01:03:14 (208.98.186.26)
Interesting that you mention the stereo separation issue of speakers that are truly "too big", along with citing the Model 14 as an example of a fairly large speaker that works well in a small room. .......
402: High Efficiency Speaker Asylum, RE: For those reccomending large speakers... (0.00)
Posted by Duke on 2011-02-26, 14:35:13 (208.98.186.26)
Counter-intuitive as it may seem, big high-efficiency horn speakers often have characteristic that actually make them acoustically MORE SUITABLE for a small room than most small speakers! A big horn s .......
403: Speaker Asylum, Should be outlawed (0.00)
Posted by Duke on 2011-02-25, 18:12:15 (208.98.186.26)
Nothing that cheap should sound that good. Especially when it's made and sold by my competitors, dammit! Duke .......
404: High Efficiency Speaker Asylum, RE: What do the numbers say about the performance of the driver...?? (0.00)
Posted by Duke on 2011-02-25, 11:04:08 (208.98.186.26)
Not much, in my opinion. We get an idea of the shape of the low-end response curve, but know nothing about efficiency, power handling (thermal or mechanical), midrange performance, impedance, etc. Thi .......
405: High Efficiency Speaker Asylum, RE: Yes. (0.00)
Posted by Duke on 2011-02-25, 10:54:27 (208.98.186.26)
The 3015LF is not very good in the midrange; cross it over low and steep if you have to use it. The 3015 is probably much better in the midrange, but it doesn't go as deep. I think the Kappalite 12's .......
406: Speaker Asylum, Interesting article (0.00)
Posted by Duke on 2011-02-25, 00:29:09 (208.98.186.26)
I agree with the author's conclusions, and put my money where my mouth is by using what might be called a simulated-sealed-box tuning in some of my designs. In others, I use room-gain-complimentary tu .......
407: High Efficiency Speaker Asylum, RE: Port placement for 2-woofer cabinet that can get rotated (0.00)
Posted by Duke on 2011-02-24, 23:10:29 (208.98.186.26)
If your ports are within 1/4 wavelength of nearby room boundary (floor and/or wall) at one octave above the port tuning frequency, you'll still get good boundary reinforcement of the port's contributi .......
408: High Efficiency Speaker Asylum, RE: Yes. (0.00)
Posted by Duke on 2011-02-24, 15:03:09 (208.98.186.26)
I can't say whether it's the neodymium or what, but the 12" Kappalites have really surprised me in direct comparisons with some pretty good woofers that are theoretically more advanced. I was original .......
409: High Efficiency Speaker Asylum, RE: Or if you have a bigger budget... (0.00)
Posted by Duke on 2011-02-20, 17:49:29 (208.98.190.241)
Thank you very much, amioutaline?. Wayne is one of my teachers, along with Earl Geddes. I just figured out your moniker. All this time, I thought it was French. Duke .......
410: High Efficiency Speaker Asylum, Yes. (0.00)
Posted by Duke on 2011-02-20, 17:37:49 (208.98.190.241)
Go to the "prices" page for the model you're interested in, and you will see a number of options. By the way, some Eminence woofers are very good. I used to be down on Eminence but now use Kappalites .......
411: High Efficiency Speaker Asylum, Easy as... (0.00)
Posted by Duke on 2011-02-20, 15:08:40 (208.98.190.241)
PiSpeakers, and go with the optional driver upgrades if possible. For orchestral, the extra smoothness is worth it. Duke .......
412: Speaker Asylum, Not enough experience, sorry. (0.00)
Posted by Duke on 2011-02-18, 19:57:09 (208.98.191.65)
I haven't heard Advents in thirty-something years, and don't think I ever heard the ARs. My expectation is that good modern woofers would have better clarity, but the overall improvement is probably s .......
413: Speaker Asylum, RE: ported bass compared to sealed bass (0.00)
Posted by Duke on 2011-02-18, 12:50:10 (208.98.191.65)
Room effects are the dominant issue in the bass region, so we should at least take into account how the speaker will interact with nearby room boundaries. Having woofer and port each interact with the .......
414: Speaker Asylum, RE: ported bass compared to sealed bass (0.00)
Posted by Duke on 2011-02-18, 12:25:55 (208.98.191.65)
A port still puts out a considerable amount of energy well north of the tuning frequency. The output of woofer and port are often equal roughly 2/3 octave above the tuning frequency. True that the di .......
415: Speaker Asylum, RE: The way Duke (I think) and others have answered that in the past (0.00)
Posted by Duke on 2011-02-18, 01:05:53 (208.98.191.65)
"...there may be more raw drivers available which are suited to ported enclosures." Yes, and fortunately such woofers tend to be pretty good at midrange as well. My top priority when choosing a midwo .......
416: Speaker Asylum, RE: ported bass compared to sealed bass (0.00)
Posted by Duke on 2011-02-17, 21:44:18 (208.98.191.65)
The biggest hurdle to smooth in-room bass is the room itself. The room typically does two things: Imposes a peak-and-dip pattern due to its modal behavior, and boundry reinforcement boosts the low end .......
417: OTL Asylum, RE: Just a note (0.00)
Posted by Duke on 2011-02-14, 23:28:05 (208.98.186.62)
I've had numerous customers who tried bi-amping the SoundLabs, only to go back to just using a single amp. I don't think any of them are still bi-amping. The impedance curves of the low-frequency and .......
418: Planar Speaker Asylum, If you can hear it but not measure it, then you're measuring the wrong thing. (0.00)
Posted by Duke on 2011-02-14, 19:25:20 (208.98.186.62)
As a designer, I've had to learn new ways to gather data (and new ways to interpret it) when my measurements didn't correspond with what I was hearing. Duke .......
419: Speaker Asylum, RE: speaker orientation--an odd question (0.00)
Posted by Duke on 2011-02-13, 00:05:54 (208.98.186.62)
Vertically aligned drivers result in more uniform sound in the horizontal plane, which is where we live for the most part. Narrow footprint speakers also have higher WAF than wide footprint speakers, .......
420: Speaker Asylum, RE: Studio Monitor (0.00)
Posted by Duke on 2011-02-12, 23:24:02 (208.98.186.62)
Pardon my ignorance of prosound usage of terms, but roughly how big a speaker are you talking about when you say "studio monitor"? A 6" two-way? A 10" or 12" three-way? Also, do you have a ballpark b .......
421: Pro Audio Asylum, RE: Division of labor in PA system-More (0.00)
Posted by Duke on 2011-02-08, 14:43:45 (208.98.186.62)
"At the risk of giving away one of my sound reinforcement 'secrets' ;) , this is often because the mids and uppers are too directional for the venue, and so I always designed systems to have wide disp .......
422: Pro Audio Asylum, RE: Division of labor in PA system-More (0.00)
Posted by Duke on 2011-02-08, 14:30:01 (208.98.186.62)
"Indoors you will need less bass cabinets to match the tops than outdoors. "This is because the bass reflections off of the walls will help to reinforce itself. Think of it being "contained" in the bu .......
423: Pro Audio Asylum, RE: Division of labor in PA system-More (0.00)
Posted by Duke on 2011-02-07, 23:33:08 (208.98.186.62)
Thank you, Tom. "In a room, one adds the fact that it is the total acoustic power and room absorption that governs the reverberant sound level for any given frequency." That's pretty much what I was t .......
424: Pro Audio Asylum, RE: Division of labor in PA system-More (0.00)
Posted by Duke on 2011-02-07, 23:15:42 (208.98.186.62)
Thanks for your input, and I was not aware of the depth of your experience. I appreciate your taking the time to respond to me here. What I'm trying to do is take your observation that the bass may be .......
425: Pro Audio Asylum, RE: Division of labor in PA system-More (0.00)
Posted by Duke on 2011-02-07, 14:09:59 (208.98.186.62)
Hi Tom, Thanks for joining in. Yes I understand equal loudness curves. Is there any merit to my previous post, which theorizes that the RTA readings back in the audience (farfield) are going to be ba .......
426: Pro Audio Asylum, RE: Division of labor in PA system-More (0.00)
Posted by Duke on 2011-02-07, 12:36:45 (208.98.186.62)
Okay not trying to dispute you here, just trying to understand. I'm not sure the RTA readings back in the audience area will correspond directly to nearfield SPL readings from the speakers. In a mode .......
427: Pro Audio Asylum, RE: Division of labor in PA system (0.00)
Posted by Duke on 2011-02-07, 10:59:40 (208.98.186.62)
Hi Inmate51, The band is not bigtime, has only done a few live performances, and is not in a position to hire an engineer. About four or five years ago I built the speakers they have been using for st .......
428: Pro Audio Asylum, RE: Division of labor in PA system-More (0.00)
Posted by Duke on 2011-02-07, 03:01:16 (208.98.186.62)
Wow, that's a lot of subwoofage. I'm talking about indoors, in fairly small venues, without an amplified kickdrum. Do you still think those numbers apply? Duke .......
429: High Efficiency Speaker Asylum, PING.... (0.00)
Posted by Duke on 2011-02-06, 00:42:47 (208.98.186.62)
Your overall approach sounds well thought-out to me, but unfortunately I don't know enough about the drivers you're using to make a good evaluation of specifics like crossover frequency and slope. I t .......
430: High Efficiency Speaker Asylum, ^^that post is a keeper^^ (0.00)
Posted by Duke on 2011-02-05, 00:50:42 (208.98.186.62)
I don't know anyone whose experience with fullrange drivers is as broad as yours. Thank you for sharing so much; I'm gonna bookmark your post for future reference. Duke .......
431: Pro Audio Asylum, RE: Division of labor in PA system (0.00)
Posted by Duke on 2011-02-04, 03:11:56 (208.98.186.62)
I did take a look, and it's an impressive design but not really the best solution for this application. The portability issue goes back more to box size than weight; the band has muscle & a dolly, but .......
432: High Efficiency Speaker Asylum, RE: synergy is the key (0.00)
Posted by Duke on 2011-02-03, 11:59:55 (208.98.186.125)
Nope, but I did use the FE206E in an earlier design, one that worked pretty well within its price range and SPL limits but "cheated" by using a built-in subwoofer and rear-firing supertweeter. Hence i .......
433: High Efficiency Speaker Asylum, RE: synergy is the key (0.00)
Posted by Duke on 2011-02-03, 09:32:40 (208.98.186.125)
"I personaly found the cone break up of full range to be worse than the issues caused by a crossover and also perfer the way a CD horn distributes sound in a typical home listening room." This was my .......
434: Pro Audio Asylum, RE: Division of labor in PA system (0.00)
Posted by Duke on 2011-02-03, 09:21:56 (208.98.186.125)
Thank you very much. Portability being a significant issue, tapped horns are not feasible. Duke .......
435: Speaker Asylum, RE: There is a certain pride of ownership... (0.00)
Posted by Duke on 2011-02-03, 09:14:19 (208.98.186.62)
"Some speaker designers find all the other drivers available for OEM's ncongruous with their vision. "Vandersteen designed his own drives because nobody else could do what he wanted, and he was not wi .......
436: High Efficiency Speaker Asylum, RE: In the 1930s, Stalina was a fairly popular girl's name. (0.00)
Posted by Duke on 2011-02-03, 01:18:21 (208.98.186.125)
Where I come from, people named their firstborn Gilletmas. Duke .......
437: Speaker Asylum, There is a certain pride of ownership... (0.00)
Posted by Duke on 2011-02-03, 00:00:03 (208.98.186.125)
...that comes with a speaker whose exclusive drivers are made in-house. Beyond that I see no inherent advantage, only an unnecessary expense in duplicating a task that a driver manufacturer is already .......
438: Pro Audio Asylum, Division of labor in PA system (0.00)
Posted by Duke on 2011-02-02, 20:45:58 (208.98.186.121)
Hello, I've been asked to put in a proposal for a PA system for a band. It's an electronica band (but they're not particularly bass-heavy), and they're looking for a high quality rig for modest-size v .......
439: High Efficiency Speaker Asylum, RE: Waveguides (0.00)
Posted by Duke on 2011-01-27, 19:10:26 (208.98.186.68)
There's a cylidrical "snout" in the throat beyond the depth required to accomodate the screw threads. In my opinion that's just too much snoutness. At any rate I didn't much like its 12" counterpart e .......
440: Planar Speaker Asylum, RE: Alternatives to Maggies (0.00)
Posted by Duke on 2011-01-21, 23:36:12 (208.98.184.147)
If you're the one paying for the house, well, that don't seem right to me. But I guess that's none of my beeswax. Much of what makes Maggies so magical is the rich abundance of spectrally-correct, rel .......
441: Speaker Asylum, What he said. (0.00)
Posted by Duke on 2010-12-23, 14:02:54 (208.98.184.18)
Crossover design is considerably more complex than most people appreciate, and it all starts with good measurements. Duke .......
442: High Efficiency Speaker Asylum, RE: port math please (0.00)
Posted by Duke on 2010-12-08, 10:57:29 (208.98.184.157)
Here's an online calculator that might be useful: http://www.psp-inc.com/tools.html Duke .......
443: Speaker Asylum, RE: Budget Bass (0.00)
Posted by Duke on 2010-12-03, 22:03:40 (208.98.184.157)
Boundary reinforcement = budget bass. Improvise stands of some sort that are only a foot or so tall, scoot 'em a bit closer to the wall, scoot your chair back up against the opposite wall, turn off th .......
444: Speaker Asylum, take a look at Zu (0.00)
Posted by Duke on 2010-10-10, 14:13:34 (208.98.184.9)
Yeah I know it's an augmented wideband format instead of a conventional two-way, and I know some of their models have been controversial in the past, but take a look anyway. Zu has some very interesti .......
445: Speaker Asylum, RE: No Duke, THANK YOU... (0.00)
Posted by Duke on 2010-10-08, 15:40:20 (208.98.184.9)
...and YOU helped put my kids through college! .......
446: Speaker Asylum, Thank you Clio09 (0.00)
Posted by Duke on 2010-10-08, 13:45:18 (208.98.184.9)
I appreciate your posting the link. And thanks to all of you who posted your support and encouragement. Duke .......
447: Speaker Asylum, RE: Crazy to spend that much if you're on the rug out of the sweet spot or doing chores round the house (0.00)
Posted by Duke on 2010-10-06, 23:55:21 (208.98.184.9)
Some designs produce a tonal balance that is just as good outside the sweet spot as in it. Live instruments do that too. I think it's a worthy goal. Duke .......
448: Speaker Asylum, RE: I was just about to comment (0.00)
Posted by Duke on 2010-10-01, 13:41:02 (208.98.184.9)
That makes sense to me, especially given the nice thick felt you're using. Duke .......
449: Speaker Asylum, RE: I was just about to comment (0.00)
Posted by Duke on 2010-10-01, 12:22:23 (208.98.184.9)
The AR "Magic" speaker, designed by Ken Kantor as I recall, used foam for rather aggressive radiation pattern control. There is a prosound company that does so today, but I can't remember their name o .......
450: Speaker Asylum, RE: Overpriced? I think not. (0.00)
Posted by Duke on 2010-09-30, 22:13:17 (208.98.184.9)
Also, the sales side of the operation can be very time-consuming. People have questions. Objections. Responses and reviews and supporting evidence has to be sent out. Then research into what shape and .......
451: Speaker Asylum, RE: In addition to reducing diffraction... (0.00)
Posted by Duke on 2010-09-29, 10:43:57 (208.98.184.9)
So with the proper tools (I've never heard of a "gasket cutter") and experience (I'm neither a boilermaker nor pipefitter apprentice), you're saying it's a piece of cake? I'm sure that's true. For the .......
452: Speaker Asylum, In addition to reducing diffraction... (0.00)
Posted by Duke on 2010-09-29, 06:06:57 (208.98.184.9)
An added benefit of Jim D. Goulding's thick felt pads is reducing excess lower-treble energy that otherwise would have skewed the reverberant field's spectral balance. At the lower end of the tweeter' .......
453: Speaker Asylum, RE: Why not planar speakers? (0.00)
Posted by Duke on 2010-09-19, 00:13:23 (208.98.184.9)
The SoundLabs that Banpuku mentions use faceted-curved panels that maintain constant directivity over a wider frequency range than a horn or waveguide. The low-level resolution of the electrostat is s .......
454: Speaker Asylum, RE: Help Please-Crossover Problem (0.00)
Posted by Duke on 2010-09-16, 10:48:30 (208.98.184.9)
Subwoofer + a horn tweeter is not a recipe for success. Padding can help, but I think you have multiple problems, such as wrong size and type of woofer and expecting a generic crossover to give good r .......
455: Speaker Asylum, RE: Looking for Guitar amp speaker covers for grills for my speakers (0.00)
Posted by Duke on 2010-09-12, 12:54:36 (208.98.184.9)
I install waffle grills as an option on some of my models, and get them from Parts Express, link below. Do a search for "grill mounting kit" also, as you'll need a way to attach the grills. If you go .......
456: Speaker Asylum, Who in their right mind?? Yours truly... (0.00)
Posted by Duke on 2010-09-06, 23:14:58 (97.126.143.4)
Inmate51 wrote: "I like to have a sound field in my room which is pleasant to hear no matter where I am. :) For typical home rooms, that requires a fairly wide dispersion at all frequencies, in order .......
457: Speaker Asylum, RE: Why No Dynamic Speakers Designed For Narrow Dispersion ? (0.00)
Posted by Duke on 2010-09-06, 10:10:27 (208.98.184.9)
I presume a coaxial wouldn't count either, as the woofer's cone would be acting as a waveguide for the tweeter? Arguably many "fullrange" drivers would qualify, especially fairly large-diameter units .......
458: Speaker Asylum, RE: Why No Dynamic Speakers Designed For Narrow Dispersion ? (0.00)
Posted by Duke on 2010-09-05, 23:03:08 (208.98.184.9)
Yes, I've tried it, and 10" or 12" midwoofers show up in most of my designs. I cross them over where their patterns have narrowed to about 90 degrees, and use a 90-degree constant-directivity waveguid .......
459: Speaker Asylum, RE: Why No Dynamic Speakers Designed For Narrow Dispersion ? (0.00)
Posted by Duke on 2010-09-05, 21:20:37 (208.98.184.9)
I experiment with something like that once, using a cluster of small-flange dome midranges surrounding a small bullet supertweeter. The pattern was not as smooth as what I could get with a horn or wav .......
460: Planar Speaker Asylum, RE: Magnepan 1.7 ad in the Absolute Sound (0.00)
Posted by Duke on 2010-09-05, 16:16:57 (208.98.184.9)
"Frugal" is a reality that few manufacturers have the courage to bring up. Most would like to present or at least imply a "no compromise, cost-was-not-an-issue" facade. That is never the case; there i .......
461: High Efficiency Speaker Asylum, KCS (0.00)
Posted by Duke on 2010-09-05, 14:35:59 (208.98.184.9)
John Kalinowski makes a wide variety of very interesting high-efficiency designs. Duke .......
462: Speaker Asylum, Will try... (0.00)
Posted by Duke on 2010-08-28, 23:27:50 (208.98.184.9)
I'm not so much advocating radiation pattern symmetry; rather, I'm looking at pattern width, both in the horizontal and vertical dimensions. The closer the pattern widths match up in the crossover reg .......
463: Speaker Asylum, RE: Yup. (0.00)
Posted by Duke on 2010-08-28, 17:07:57 (208.98.184.9)
Yes, I too would very much like to hear about Kal's speaker designing background. We're here for you, buddy! Let it out! I was a closet amateur speaker designer from 1979 to 1985, when I finally "came .......
464: Speaker Asylum, RE: SORRY (0.00)
Posted by Duke on 2010-08-28, 11:04:58 (208.98.184.9)
I like the SCM634 best. The thing I look at is getting a good transition between midwoofer and tweeter, and part of that is minimizing the radiation pattern discrepancy between the midwoofer and twee .......
465: Speaker Asylum, RE: Morel CARBON driver for a 2 way speakers? (0.00)
Posted by Duke on 2010-08-27, 13:49:22 (208.98.184.9)
The one they're calling a "midrange" (SCM634) has a better-looking response curve in my opinion. The other one has a slightly more powerful magnet. I'd go with the "midrange", as its parameters and ex .......
466: Speaker Asylum, RE: This is what some speaker designers have told me (0.00)
Posted by Duke on 2010-08-27, 12:41:31 (208.98.184.9)
Being able to identify that there's a problem in the crossover, by ear, isn't so rare (and it can be bluffed). Now being able to interpret exactly what the problem is accurately enough to know what cr .......
467: Speaker Asylum, RE: Speakers Designed By Ear (0.00)
Posted by Duke on 2010-08-27, 11:14:37 (208.98.184.9)
Getting a good correlation between measurement and perception is not trivial, but once it has been done, the design process is greatly facilitated. It then becomes possible to identify what is causing .......
468: Speaker Asylum, RE: 100°x100°; defintely agree (0.00)
Posted by Duke on 2010-08-25, 19:05:07 (208.98.184.9)
I didn't realize the Model 19's treble extended higher than its predecessors. Good move on Altec's part. At the other end of the spectrum, that big ten or eleven cubic foot cabinet puts the 19 virtual .......
469: Speaker Asylum, RE: My exposure to Audiokenesis (0.00)
Posted by Duke on 2010-08-25, 18:49:07 (208.98.184.9)
Thank you very much, Frihed89. What year and what show, if you don't mind? Or if you can't remember the year, can you tell me the general color and approximate shape of the cabinets? That's a pretty .......
470: Speaker Asylum, RE: 100°x100°; defintely agree (0.00)
Posted by Duke on 2010-08-24, 18:52:10 (208.98.184.9)
Definitely agree, though like the Altec Model 14 and Model 19, these outstanding JBL monitors are no longer in production. The 4430 is a landmark loudspeaker, in my opinion anyway. Before he designed .......
471: Speaker Asylum, RE: Any really good horn speakers ? (0.00)
Posted by Duke on 2010-08-23, 21:25:22 (208.98.184.9)
Horn coloration has two sources: Frequency response anomalies (usually peaks) that may or may not show up on-axis, and reflections within the horn itself. Starting out with an inherently low-coloratio .......
472: General Asylum, Guido Corona (mt) (0.00)
Posted by Duke on 2010-08-11, 23:04:48 (208.98.184.9)
empty .......
473: Speaker Asylum, RE: speaker service question (0.00)
Posted by Duke on 2010-08-11, 13:37:36 (208.98.184.9)
Well to a certain extent it depends on the crossover topology; sometimes parts can fail and signal will still get through to the tweeter. In this case I would guess that either something in series wit .......
474: OTL Asylum, RE: Sadly... (0.00)
Posted by Duke on 2010-08-04, 17:27:33 (208.98.184.9)
Thanks for mentioning my Dream Makers. Actually, I have a half-dozen models that will work with the M-60 or S-30. Duke .......
475: Speaker Asylum, Audibility of group delay is marginal (0.00)
Posted by Duke on 2010-08-04, 11:46:56 (208.98.184.9)
What is clearly audible is the frequency response curve; tests that isolate group delay reveal that, in and of itself, it is barely audible. So while a system with greater group delay may well have su .......
476: High Efficiency Speaker Asylum, Good point (0.00)
Posted by Duke on 2010-08-03, 12:02:56 (208.98.184.9)
Thanks for the correction; I knew better but lapsed into lazy wording. Duke .......
477: High Efficiency Speaker Asylum, RE: BEYMA CP385/ND and FAITAL PRO LTH102 Tractrix Horn (0.00)
Posted by Duke on 2010-08-03, 10:09:13 (208.98.184.9)
I use the CP385/ND in most of my commercial models, and it was chosen after a rather exhaustive evaluation of many possible contenders. Eyeballing the narrow-pattern Faital tractrix horn, it's not so .......
478: High Efficiency Speaker Asylum, RE: Defection (0.00)
Posted by Duke on 2010-08-02, 13:38:51 (208.98.184.9)
Just like everyone else here I have pretty strong opinions about which approaches give the best results, so I'll try to stick to topics that most of us are likely to agree on. 1) A smooth impedance cu .......
479: Speaker Asylum, RE: 12" Subwoofer Question (0.00)
Posted by Duke on 2010-07-28, 19:46:35 (208.98.184.9)
There is a technique of shorting the second voice coil, which in some cases might be useful. Qes is doubled while Qms is greatly reduced, resulting in a Qts in between the non-shorted single-coil conf .......
480: Speaker Asylum, RE: 12" Subwoofer Question (0.00)
Posted by Duke on 2010-07-28, 11:42:12 (208.98.184.9)
The Qes of the driver will be doubled if he only uses one voice coil, and that will totally screw up your calculations and result in a boomy sub. Also, the thermal power handling is halved with only o .......
481: Speaker Asylum, RE: 60% (0.00)
Posted by Duke on 2010-07-21, 14:44:44 (208.98.184.9)
"I know there is a dimishing return aspect for all equipment - but it seems to hit later in loudspeakers - that is... more of a linear relationship in the early upgrade steps." I agree with your obser .......
482: High Efficiency Speaker Asylum, RE: Altec Model 19 Vs. modern horns (0.00)
Posted by Duke on 2010-07-20, 16:03:53 (208.98.184.9)
I'm pretty sure you can find shout-free alternatives from KCS and/or Bill Woods. What I am not so sure about in your price ballpark is the combination of bass extension and efficiency made possible b .......
483: Speaker Asylum, RE: TAS did a long piece on Iverson in the mid-1990s... (0.00)
Posted by Duke on 2010-07-16, 18:32:23 (208.98.184.27)
I spoke which John a few days before his disappearance, as described in the link below. Duke .......
484: High Efficiency Speaker Asylum, RE: dust caps (0.00)
Posted by Duke on 2010-07-14, 14:10:57 (208.98.184.27)
The dust cap may be an important structural element of the cone, in which case removing it would change the breakup behavior. The dustcap may be a significant radiating surface at high frequencies, i .......
485: Critic's Corner, Critics have contributed to the pursuit of excellence (0.00)
Posted by Duke on 2010-07-08, 15:57:43 (208.98.184.27)
Without someone in a position of prominence qualified to recognize excellence within the context of a broad cross-section of competing systems, the incentive to build a better product would be diminis .......
486: General Asylum, RE: Your speakers may be more adjustable than you think (0.00)
Posted by Duke on 2010-07-08, 08:32:10 (208.98.184.27)
What foam to use and how much falls into the "trial and error" category, and if you want it to function as a resistive (or highly damped) vent use an open-cell foam. The test is whether or not you can .......
487: General Asylum, Your speakers may be more adjustable than you think (0.00)
Posted by Duke on 2010-07-07, 23:09:28 (208.98.184.27)
Often the tuning of a ported speaker can be lowered by narrowing the vent opening and/or lengthening the vent (by means of a smaller-diameter inserted tube, building up the outer diameter of the small .......
488: Speaker Asylum, Yes and No (0.00)
Posted by Duke on 2010-07-06, 18:01:25 (208.98.184.27)
Few major advances in transducer technology, but a fair amount of incremental improvement. The biggest advances imho are in how to apply the technologies we already have, arising from improved unders .......
489: Speaker Asylum, RE: depends (0.00)
Posted by Duke on 2010-07-05, 11:38:40 (208.98.184.27)
Well, my experience has been different. Not long ago I was working on two different designs at the same time, one of them using a fullrange driver and the other a two-way. The parts costs including cr .......
490: Speaker Asylum, depends (0.00)
Posted by Duke on 2010-07-04, 22:37:32 (208.98.184.27)
Assuming you've chosen woofer, midrange, and tweeter based on how well they will work together - as well as with enclosure, room and amplifier - the next step would be to make detailed measurements to .......
491: Speaker Asylum, What kills speakers is heat (0.00)
Posted by Duke on 2010-06-27, 14:46:18 (208.98.184.27)
A voice coil can be overheated by a clipped signal or an unclipped one. It doesn't care what the signal looks like, only how much wattage is delivered. Clipping can raise the average wattage delivered .......
492: Planar Speaker Asylum, Headroom of the sealed Swarm, and in-room bass extension (0.00)
Posted by Duke on 2010-06-23, 23:12:20 (208.98.184.143)
The EFT 8b is rated at 83 dB and can handle 200 watts, for a theoretical maximum SPL of 106 dB, not counting thermal compression. Each sealed Swarm module is approximately 82 dB at 100 Hz, and assumin .......
493: Amp/Preamp Asylum, RE: General thoughts on running a SS Pre with Tube Amps (0.00)
Posted by Duke on 2010-06-23, 16:53:12 (208.98.184.143)
In my opinon the amp/speaker synergy is the second most important in your system (behind speaker/room). Look first at your speakers to decide whether a tube amp would work with them. If so, then yes a .......
494: General Asylum, RE: Help - I'm hearing song beginnings slightly early on my records (0.00)
Posted by Duke on 2010-06-16, 16:22:00 (208.98.184.143)
yes, that's a very common phenomenon... YES, THAT'S A VERY COMMON PHENOMENON... Sorry, couldn't resist. Plagarized from an old Stereo Review cartoon. Steve Eddy explained it. Pre-echo typically lasts .......
495: Planar Speaker Asylum, no harm, no foul (nt) (0.00)
Posted by Duke on 2010-06-11, 10:22:01 (208.98.184.143)
.......
496: Planar Speaker Asylum, Misunderstanding (0.00)
Posted by Duke on 2010-06-10, 16:12:27 (208.98.184.143)
Ah. I thought your experiment was intended to disprove something I'd said {"You might be surprised at the results"), and made an assumption about what your position was. My apologies. The internet is .......
497: Planar Speaker Asylum, RE: really? (0.00)
Posted by Duke on 2010-06-10, 12:50:58 (208.98.184.143)
You probably know most of this, but just for anyone following along who doesn't: Low-pass filters are not brick walls. They allow some lower midrange energy to get through, how much depending on the f .......
498: Planar Speaker Asylum, RE: really? (0.00)
Posted by Duke on 2010-06-10, 10:44:53 (208.98.184.143)
It's very difficult to localize a low bass source in a room because the ear/brain system needs more than one cycle to even register the presence of low frequency energy, and several cycles to detect p .......
499: Planar Speaker Asylum, RE: Maggies acts like a line source speaker (0.00)
Posted by Duke on 2010-06-09, 23:19:49 (208.98.184.143)
Ah, I didn't realize you were talking about the MC1. I'd say just use your H-frame sub and set the levels for your normal listening distance. If you have more than one normal listening distance you m .......
500: Planar Speaker Asylum, RE: Maggies acts like a line source speaker (0.00)
Posted by Duke on 2010-06-09, 20:02:50 (208.98.184.143)
I used to have a hybrid speaker with dipole panels atop a monopole woofer section. Pink noise measurements at various distances showed that the panel definitely fell off more slowly with distance than .......
Found total of 500 records, Query: , Author: Duke in All Forums, Time: 2 sec.