Timothy C. May writes:
Not familiar with the Nyquist limit w/ regards to sampling rate vs frequency :(
Check any textbook, or even a good dictionary. Basically, it says that one must sample at more than twice the frequency of the highest frequency to be reconstructed. Thus, a 20 KHz top frequency needs at least 40 K samples per second. The exact number is, I think, about 2.2x the freqency, which is why CDs were standardized at 44 K samples per second per channel.
The Nyquist Theorem states you need exactly twice the samples, not over twice. The magic number isn't something like 2.2, its exactly 2. Now, the reality is that low pass filters in the recording studio aren't going to be perfect and such, being analog devices, and higher frequencies making it in will cause aliasing artifacts, so you probably want to sample at above twice your putative cutoff because it won't be your real cutoff, but in principle you need exactly twice the highest frequency. Perry