Mark Lanctot;187133 Wrote: > > If the subtraction effects were overridden with time differences, the > effects would be random but 128 kbps clearly drops more material than > 320 kbps in this case, as you would expect. In fact the 320 difference > test shows almost no differences in the guitar riff until the big cymbal > crash. Interestingly, the cymbal crash drops a lot of material for all > tests.
Well I'd be very skeptical of results obtained this way. Even if there's no overall time difference, phases distortions will show up much more clearly in this than changes in the frequency response, even though the former are completely or almost completely inaudible in the signal. Just as an example, take one filter that reduces the power in everything above 5 kHz by 10%. That would be easily audible, and show up in your test as high frequencies with pretty small amplitude. On the other hand, suppose instead you leave the power alone but flip the phase of everything about 5 kHz. In your test that would give a huge signal - twice the amplitude of the original signal for everything above 5 kHz - but that's totally inaudible. So any interesting effects here are liable to be swamped by phase distortions - this technique will only work if you're sure there are none at all, which is rather unlikely. -- opaqueice ------------------------------------------------------------------------ opaqueice's Profile: http://forums.slimdevices.com/member.php?userid=4234 View this thread: http://forums.slimdevices.com/showthread.php?t=32576 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
