opaqueice wrote: > Just ask yourself what the difference is between a 20 kHz square wave > and a perfectly smooth 20 kHz sine wave. > > Answer - a 60 kHz sine wave (plus higher frequencies). So if you can > hear 60 kHz, you'll know the difference.
I'm lost. Nyquist deals with sine waves. Any square wave is the infinite sum of infinitively many sine waves of increasing (to infinity) frequency. See Taylor series and Maclaurin series. You can't talk about the bandwidth of a square wave. You can talk about a square wave with a primary frequency of X, as your 20kHz example. Its not one frequency when you think of sine waves. The harmonics of a 20kHz square wave must be filtered out if you are sampling at any frequency. For a 44.1kHz sample, this means that the 40kHz, 60kHz, 80kHz, etc. signals have to go before the ADC. BTW, I've never heard of a square wave in real music. Synths, sure. They usually start with either square or sawtooth waves. But real instruments generate modulated sine waves. _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/lists/listinfo/audiophiles
