High Efficiency Speaker Asylum: Re: We disagree on a couple of points by EGeddes Need speakers that can rock with just one watt? You found da place.

For Sale Ads FAQ / News / Events

Posted by EGeddes (P ) on February 22, 2006 at 11:00:41

In Reply to: Re: We disagree on a couple of points posted by tomservo on February 22, 2006 at 09:37:17:

Tom

About the horns I think that we are agree for the most part. Clearly the LF horn will have lower distortion at higher levels than a direct radiator, but just as clearly it will have more coloration from the internal standing waves than the direct radiator at any level. Now which is the greater problem and hence the better tradeoff. For home use I claim that LF distortion is not really a problem at all, but the horns colloration will be. Size isn't really the issue.

At some point, and here is where we probably disgaree, the disortion will become a greater problem than the coloration - if we are limited to a single driver. Then the horn is the better tradeoff - if you are limited to only the one driver. But one can always throw more drivers at the problem to get the distortion down, but the colloration is always in the horn.

But about the distortion topic I don't think that you have got what I am saying correct.

"There are your findings based on the results of your study which (I have not read it yet but I will) which finds a MUCH higher level of distortion is needed to be detectable with selected music
(a criteria for a subjectively flawless musical reproducer).

So is distortion or nonlinearity above some amount audible or not ?"

We did not find "much higher levels of distortion", we found no relationship between the standard methods of specifying this distortion and its perception. Yes, distortion and nonlinearity is clearly audible. But the issue is that one cannot determine this aidibilty from THD or IMD tests. One finds that .01% THD can sound awful in one circumstance while 50% THD can be inaudible in another. So the point is that THD and IMD are useless as indicators of audiblity. Or proposed metric was shown to be highly correlated with perception - about .95 versus THD at -.2. This data is all on my web site.

And we tested even versus odd distortion in our test and found no differences.

Now we did not test every single circumstance that one can come up with. We did not test for differences between LF and HF perception. It was a simple test, but sufficient to deflate a lot of "current dogma". The low results for THD and IMD means that these cannot be relied upon as indicators of perception. They may work in certain instances, but clearly they don't in others. Thus they can not be relied on.

The nature of these kinds of subjective tests is such that they tend to only be able to discard concepts and virtually never result in showing the answer. Thus to get to the answer one can only do this by discarding everything else and as such one can never be sure that they have discarded everything else. So there is never really an absolute answer, but there can be absolute errors.

Talk to you later.

Earl Geddes

This post is made possible by the generous support of people like you and our sponsors:

Sonic Craft

---

[ Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]

---

[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]

---