🚀 go-pugleaf

john@anasaz (John Moore) writes:
> 
> For example, consider synthesis of a 10 KHz sine wave with a sampling
> rate of 44 KHz. In our case, we used an 8 bit representation of the
> signal. This quantizing process produces harmonic distortion (it wouldn't
> with an infinite bit representation). This means there are components
> at 20, 30, 40, etc KHz (assuming evens or odds not cancelled). This
> will mix with the sample rate and produce an alias at 4 KHz and 14 KHz.
> It doesn't make any difference how good your LPF is - the mixing has
> occurred before you get to it.
> 
Well not exactly right.  The "harmonic distortion" as it is called here is not
from the the quantization of the signal but from the sampling.  For example
the output from a sample and hold circuit can be consisdered to be an
infinite precision A/D converter.  But if you look at the spectrum you'll
see the original signal's spectrum plus images of the original spectrum
centered around multiples of the sample frequency (or the "harmonics").

Quanitazation can be modeled as a noise added to the signal.  It really
doesn't add distortion although I can't imagine a quantization process
without sampling.