23 May
2013
23 May
'13
4:17 p.m.
On Thu, May 23, 2013 at 12:18:25PM +0000, Fons Adriaensen wrote:
Take a filter for a 48 kHz DAC. It could be -0.5 dB at
23 kHz,
-12 dB at 24 kHz, and -100 dB at 25 kHz. Any aliasing will be
either above 23 kHz or below -100 dB, probably harmless.
Given the passband and stopband constraints at 23 and 25 kHz,
the actual value at 24 kHz is more or less irrelevant.
The potential intermodulation effects referred to in the paper
by Julian Dunn are real, but not realistic. If such signals
(high energy well above 20 kHz) are present you'll have some
serious problems even in a completely analog system.
True, although I'd have more confidence in a filter that eliminated
the possibility entirely.
I couldn't resist responding to the statement in the thread title:
"No difference between analog and digitally processed sound".
As in so many things, "that depends".
John