[PD] smallest possible value of a delay-time

Roman Haefeli reduzierer at yahoo.de
Mon May 17 17:40:38 CEST 2004

Mathieu Bouchard <matju at sympatico.ca>:
> Any idea why subsample delays would be useful?

yeah, the problem is karplus-strong-synthesis. the sound is generated by
feedbacks, so the length of  the delay determines the frequency. if the grid
of possible delay-values is 1 sample, you get very large spaces between the
resulting frequencies. (f = srate / delayinsamples). it's not only about
smaller than 1 sample, but more precise than a sample. have a look at the
beginning of this discussion.

> Suppose you have a signal at exactly the Nyquist frequency and
> RMS=sqrt(2). Then its data is like +1,-1,+1,-1,...

yeah, i see the problem with the phase. but i'm still not sure if it is a
problem with lower frequencies than the nyquist-freq. generate a freq that
you can still hear (maybe 16kHz). you admit, that it sounds constant
although it looks not quite like sine-wave? where ever you start to play it
you start with a different phase. so i don't see your argument that you
reduces  the possible states of phase with high frequencies.


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