"Erik Squires" wrote in
ervers.com:

So, here's my question. If I digitize a 15 kHz signal, using a 44.1
kHz sampling rate, I'm going to get about 3 samples / cycle.

Are the normal digital filters good enough to reproduce a 15 kHz
singal with varying amplitude? How accurate is that signal, is there
no lag in the reconstructed signal? I mean, if the amplitude of the
original changes, is the reconstructed signal as true at 15 kHz as at
4 kHz?

This to me is a far more important concern than whether I can hear
20+kHz signals.

Thanks for your intelligent and well thought out replies. The rest of
you can suck my electric outlet.

Erik



First, with 44.1kHz sampling & 20-22kHz bandwidth a 15kHz signal can only
be a sine wave. Second, the 15kHz signal cannot be one isolated sine
wave, that would require more bandwidth. It will be a burst of waves with
a minimum buildup and decay. So it will be more than 3 samples of one
cycle. The closer the sine wave is to 22.05kHz the longer this build up
and decay must be to meet the bandwidth constraint.

Tim

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