Last week was my first exposure to Pure Data. Yesterday I downloaded Max. I'm a C++ programmer by profession (computer games) with a strong interest in experimental sound synthesis.
For my fist experiment, I'm tinkering with the Karplus-Strong algorithm. I'm sure most of you are familiar with it. It's a tapin~/tapout~ delay with a onepole~ in the feedback loop. You have seen it a thousand times.
I noticed that when I reduce the cutoff frequency of the onepole~, the pitch goes down, and my notes sound flat. This is especially noticeable in the higher registers.
I speculate that the onepole~ introduces an additional delay, that gets longer as the cut off frequency gets lower.
Am I right? If that is the case, I think I could keep the pitch stable by reducing the length of the tapin~/tapout~ to compensate for the delay that is introduced by the onepole~.
But that would require me to compute the delay that is introduced by the onepole~ filter, as a function of the cut off frequency. How do I do that?