3 ms·
I don't see how either of these papers solidly refute "because Nyquist" in the context of the article and sample rates applied to audio signals. They're both wo
by mutagen 12y ago
I don't see how either of these papers solidly refute "because Nyquist" in the context of the article and sample rates applied to audio signals. They're both worth considering, though.
The first[1], the more theoretical of the two, is focused on digital communications where a Nyquist rate derived from the signal rate isn't enough to recover the signal function. The numerical examples given highlight recovering a sine wave from two, three, and six samples. The millions of samples in a single song might as well be infinite compared to these.
The second paper is much more practical and gives a number of real-world examples where naively applying Nyquist causes problems. The first, cutoff filters at half Nyquist to avoid aliasing, plauged many early CD players and other digital audio equipment. The second example is great as well, showing how understanding the signal being measured is important. The third example doesn't really apply to the subject at hand but is a good example of using aliasing for good. The fourth and fifth address the effect filters have on the signal. The sixth example refers to time response in control systems and minimizing phase delay to avoid oscillations.
[1]http://www.academia.edu/8412078/Is_The_Nyquist_Rate_Enough http://www.academia.edu/8412078/Is_The_Nyquist_Rate_Enough
[2]http://www.wescottdesign.com/articles/Sampling/sampling.pdf http://www.wescottdesign.com/articles/Sampling/sampling.pdf