Subject: Re: Frequency response was Re: [linux-audio-user] Audiophile CD's
From: Ben Saylor (bsaylor_AT_macalester.edu)
Date: Mon Jan 28 2002 - 18:18:07 EET
On Mon, Jan 28, 2002 at 02:40:13PM +0000, Tony Lambley wrote:
> > > Does sampling at f=2b loose any information?
> >
> > Nope. Sampling at f=2b will capture the same information as f=3b or 4b or
> ...
> > The only difference is that for f=nb, for n > 2, you'll waste a lot of
> space
> > storing extra samples ::-).
>
> What happens when you sample a 1Hz sine with 2 samples a second, and those
> samples happen to coincide with the zero crossover points?
That's why it's necessary to sample at f > 2b -- information is lost
when there isn't a sample close enough to the peak/trough of the wave.
I'm not sure how much greater than 2b f has to be, but apparently others
have determined that 44.1khz or 48khz is high enough to reproduce
frequencies up to 20kHz.
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