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Old 2nd February 2013, 06:09 PM   #34081
1audio is online now 1audio  United States
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Quote:
Originally Posted by PMA View Post
Tuned Lynx L22.
That's impressive. And details? Its THD about 15 dB better than the chip seems capable of. On the selftest of the card its not close to those numbers. RightMark Audio Analyzer test : Lynx L22 I would like to duplicate those results as would many here.
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Old 2nd February 2013, 06:16 PM   #34082
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BV might tell us more. If I remember well he had swapped some opamps, runs in balanced mode and at optimal I/O levels. Any soundcard needs careful approach to get the best of it.
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Old 2nd February 2013, 06:46 PM   #34083
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Originally Posted by TheShaman View Post
You don't care about a lot of things, PMA, including measurements - selectively, of course.
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Originally Posted by PMA View Post
Thanks for your input, John.
Quod erat demonstrandum (ὅπερ ἔδει δεῖξαι).

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Old 2nd February 2013, 07:54 PM   #34084
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I would like to duplicate those results as would many here.
Use I/O levels close to -17dBFS, that´s all. It seems to be optimal level for minimal distortion for L22.
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Old 2nd February 2013, 11:11 PM   #34085
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Originally Posted by Tom Danley View Post
Hi Guys
Mr Danley
Yes Group delay plots can show an overall picture, but one needs to focus on the “generic” (acoustic) phase plot http://bksv.at/doc/17-198.pdf while developing a speaker system
I too am convinced that working only on correcting the amplitude part of the measured freq response is -acoustic wise- wrong.
It is the steep curves in the phase response diagram that correlate with problems in the reproduction of transient signals in speech and music.

Regarding your description of Dr. Heyser work, I assume you are describing this (or a refinement of it)
TIME DELAY SPECTROMETER


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Originally Posted by kgrlee View Post
I'm surprised to find that I was carrying out similar experiments around the same time Is Linear Phase Worthwhile? though with a rather different slant. My conclusions were very similar.
Ricardo
I don’t have access to AES publications, so I can’t read your paper.
But Blauert's criteria for low frequencies is quite relaxed (around 4ms) compared to mid frequencies GD (0.4ms)

George
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Old 2nd February 2013, 11:28 PM   #34086
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Originally Posted by TheShaman View Post
You don't care about a lot of things, PMA, including measurements - selectively, of course.
Actually its JC who doesn't care about measurements ... even measurements that he's at pains to tell us ad nauseum, are important like Hirata, Quan & even simple THD & 7th harm.

I'm pleased to see that in Jurassic times, JC actually did measure things but this millenium, he's got out of the habit. And when he does measure things, they are certainly not for the consumption of us Unwashed Masses.

Pavel, on the other hand, has posted many measurements to support his views. Maybe, in the next millenium, JC will do likewise.
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Old 2nd February 2013, 11:50 PM   #34087
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George,
Thanks again for a great read on the transient phase response of loudspeakers. I do believe that we both have the same idea here as regards speaker development. I can't fathom why so many worry so much about a slight phase shift on the electronics side but tend to want to ignore the issue of a much greater magnitude in a loudspeaker. And I also believe that it is the extreme phase shifts in the response plots that are making so many say that we need to remove the upper frequency response of loudspeakers for them to sound good.

John C,
I think that if you go back and read the books by
High Performance Loudspeakers: Martin Colloms: 978047009430

I believe you will see why the majority of dome tweeters have such response problems. There is no perfect solution for the problem but some dome tweeters are much better than others. It really is not much different from trying to use a cone driver to cover the upper frequency response range, the cone breakup modes are just to severe for that to happen and dome tweeters suffer the same fate in the upper frequency range. If domes would actually stay as a dome as we see them things could be different but the shape of the dome doesn't look anything like the rounded dome we think is producing those sounds. It looks more like someone smashing in a dust cap than a dome at higher frequencies.
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Old 2nd February 2013, 11:52 PM   #34088
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Originally Posted by PMA View Post
And please do not quote audiophile magazines impressions, they are useless.
A bit o entertainment:

Audio Reviews

Last edited by elektroj; 3rd February 2013 at 12:17 AM.
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Old 3rd February 2013, 12:10 AM   #34089
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Originally Posted by Esperado View Post
Yes, John, pots are EVIL
Those pots in SSL consoles are nothing, compared to number of Blackmer gain cells that the signal must go thru.
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Old 3rd February 2013, 12:19 AM   #34090
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thanks Kindhornman. I have a couple of Collom's books on my shelf.
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