Phil Leigh;348690 Wrote: > Actually, Nick, in Audacity it is as near perfect as it is possible to > be - the sample values aren't being recorded via an ADC they are being > written to disk as pure numbers by a simple algorithm. I'd agree that > Audacity can't record a perfect squarewave from an analogue source but > that's not what I'm doing here...and of course the only way to play the > numbers is via the reconstruction filter after the DAC - at which point > it loses its perfection!
This is wrong. When you have a 44.1KHz PCM file, it is implicit that the signal is band-limited to the Nyquist. This is the case whether it was sampled, generated mathematically, typed by hand, whatever. Just because the numbers go -32767, +32768, -32767, 32768, for example, does not mean that they represent a square wave. You could in practice sample those values by recording a full-scale 22.050 sine wave, and that would be the correct output for a DAC to play given those numbers as input. It would also be the correct waveform to generate if that data were mathematically resampled to a higher frequency. -- seanadams ------------------------------------------------------------------------ seanadams's Profile: http://forums.slimdevices.com/member.php?userid=3 View this thread: http://forums.slimdevices.com/showthread.php?t=53345 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
