Re: High frequency recording

["Scott Fraser" scottbfraser]

<< Put simply, a 20KHz sound is only sampled about twice per
waveform, and the position of those two points will vary. You can't
define even a simple sine wave with only two points which could be at
plus and minus extremes or near zero. If you zoom in on a sound editor
you will see a ragged trangular shape between the sampling points.>>

While it is true that 2 samples hardly accurately represent a sine  
wave, in practice there is a steep LPF in the DAC at a frequency  
between the fundamental (in this case 20kHz) & its first harmonic. A  
20kHz wave represented by merely two samples will thus be rendered  
with no harmonics. A wave with no harmonics, i.e. just a fundamental,  
is in fact a sine wave. So you can't really look at the waveform as it  
is stored in the digital realm. That only gives you half the picture.  
It has to be rendered back to analog & then it really is a sine wave.

Scott Fraser