What happens if you upsample the signal to a sample rate high enough so that you can do a single sample delay, and then downsample again? There are various interpolation techniques for this I think, and you are not limited to lineair interpolation, which I suspect that this does work.Not sure if you can do it in pd though.
you should ask the music-dsp list, or the csound list. I think in csound they solved the tuning of the karplus-strong this way. But again I am not sure.
regards
Gerard
On Friday 14 May 2004 00:09, Roman Haefeli wrote:
this discussion went up when we talked about the karplus-strong-sythesis. so it is not about getting this short delay in realtime. it is about a sythesis that tries to simulate string and other percussive instruments. the problem is, that the frequency of the sythesized sound is dependent from a delay-time (frequency=1/delaytime). if the quantization of the delaytime is 1 sample, you can't play any frequency you want with this sythesis (for example: you want freq of 5000. how many samples long is the delay: 44100 / 5000 = 8.82 samples delaytime > 8.82 truncated> 9. freq with 9 samples delay = 44100 / 9 = 4900 >>> you get an error size of 100Hz or 2%) .
with your idea, it's maybe possible to play any frequency with karplus-strong-sythesis.