Hallo, Roman Haefeli hat gesagt: // 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%) .
A delay simply is a sound recorder and player. In earlier times, they were done with tapes, that were just shorter than tapes for real recordings, and looped.
Thinking of tapes as simple sample recorder/players or even as some kind of adc/dac combination, they must follow the same rules as other samle players, that is: the max frequency they can record or play is Nyquist frequency, that is half sample rate. The shortest possible delay time then in theory is 1/nyquist[Hz] seconds.
The second question then is: Can you have delays not quantized on samples? This looks as if it's the same problem as a basic wavetable oscillator has, like tabplay~. They also play a short buffer for a certain time, that doesn't have to be exactly on a sample, but can be in between.
Ciao
Frank Barknecht _ ______footils.org__