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Old 7th January 2012, 09:33 PM   #621
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Quote:
Originally Posted by Steve Eddy View Post
Thanks, one of those transfer functions is a pretty horrible non-physical crossover region with discontinuities that have singularities in the derivatives. I don't use LM324's why should anyone?
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Old 7th January 2012, 09:48 PM   #622
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Scott, you work for an IC company, you can use anything that you want. However, much mid-fi equipment will NOT use ADI and will probably use the cheapest stuff possible. Do you guarantee that every IC now commonly available for audio has a good enough transfer function?
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Old 7th January 2012, 09:57 PM   #623
DF96 is offline DF96  England
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The discontinuities had to be smoothed away when calculating the metric, so might have affected the results. The metric value for these would be more or less wholly determined by the smoothing applied, so there would be scope for adjustment.
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Old 7th January 2012, 10:13 PM   #624
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X-over distortion in any form is bad, sonically.
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Old 7th January 2012, 10:35 PM   #625
wahab is offline wahab  Algeria
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Hitachi decades old lateral fets allow for 10V wide crossconduction region
with as low as 100mA quiescent current/device for a three pair push pull , it should
keep any crossover distorsion being more of a ghost than an actual problem.
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Old 7th January 2012, 11:00 PM   #626
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I agree with Jon here: when building something for high end potential flaws have to be examined under microscope. Like, apply 1 MHz triangle on full swing to see close how it behaves on 20 KHz sine. If it is subtle on oscilloscope and hard to measure, it may be well audible as "something is odd". But if it looks nice, fronts of squares are equal, that means at least stereo image would not be blurred by phase intermodulation.
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Old 7th January 2012, 11:03 PM   #627
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Quote:
Originally Posted by john curl View Post
X-over distortion in any form is bad, sonically.
That's why I don't like symmetrical amps in this regard: single ended amps can't have them at all. But in order to save trees and the world from global warming I use push-pull topologies.
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Old 8th January 2012, 01:59 AM   #628
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The discontinuities had to be smoothed away when calculating the metric, so might have affected the results. The metric value for these would be more or less wholly determined by the smoothing applied, so there would be scope for adjustment.
I saw, this adds an element of contrivance however small. In any case a transfer function this bad would hardly be expected when comparing reasonably well designed products.
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Old 8th January 2012, 02:26 AM   #629
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LIKE DUH, Wavebourn, of course single ended amps don't have Xover distortion. They are ALL Class A!
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Old 8th January 2012, 02:47 AM   #630
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Quote:
Originally Posted by john curl View Post
LIKE DUH, Wavebourn, of course single ended amps don't have Xover distortion. They are ALL Class A!
DUH, John, and they EAT electricity!

I bought some cheap PCB with 4x100W class D amp, going to try for woofers and subwoofer... Have no time now though, wife is coming from Florida (conference), need to clean up in the house... Bought 4 boxes of such drivers, $1 each, need to find the place for them in my barn... Going to try tall open baffle line arrays.

Click the image to open in full size.
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