nick_charles
Headphoneus Supremus
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- Feb 26, 2008
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Quote:
Every heard of phase distortion? If you see a DAC with a razor flat frequency response odds are good that it has a lot of phase distortion in the treble.
We are aiui typically rather insensitive to phase distortion and you do not get that much anyway from a DAC, you are talking about delays of some ns whereas we tend not to notice it till it gets to several microseconds.(Lipshitz) and at higher frequencies the ear is much less sensitive anyway.
Quoter Floyd Toole
It turns out that, within very generous tolerances, humans are insensitive to phase shifts. Under carefully contrived circumstances, special signals auditioned in anechoic conditions, or through headphones, people have heard slight differences. However, even these limited results have failed to provide clear evidence of a 'preference' for a lack of phase shift. When auditioned in real rooms, these differences disappear.."(The piano note demo shows that if you accept a broad definition of "contrived" you can get more than a "slight" difference).
If you look at Stereophile's DAC measurements there are many expensive products with flat FR, viz deviating by no more than say 0.25db from 20 - 20K - perhaps we have different definitions of flat, sorry if that is so, certainly a .25db drop off at 20k would seem trivial to me as it is in an area of very poor sensitivity.