Tuning Stringresonator (karplus strong)


    Oct 25 2006 | 9:54 am
    Hi,
    I'm having troubles with tuning a stringresonator i made (karplus strong). I've tried many things, analyzed frequencies, looking at the vectorsize...
    But i can't get it right, even can't even get a clear octave out of it.
    Does anybody know how to this properly?
    Thanks in advance,
    poul
    Patch:
    max v2;

    • Oct 25 2006 | 1:55 pm
      I've been on this case for a while. I asked Luke Dubois, who
      bassically, said that it was technically impossible but suggested
      adding a tiny bit of noise to the delay time and then everything
      sounds in tune.
      the reason is A, that all frequencies dont fall easily into a
      specific number of samples and B, the vector thing.
      gotta go. sorry for no more info
      -matt
    • Oct 25 2006 | 2:53 pm
    • Oct 27 2006 | 7:21 am
      poul wrote:
      > Hi,
      >
      > I'm having troubles with tuning a stringresonator i made (karplus strong). I've tried many things, analyzed frequencies, looking at the vectorsize...
      >
      > But i can't get it right, even can't even get a clear octave out of it.
      >
      > Does anybody know how to this properly?
      I had exactly the same problem. The reason is that the feedback is
      limited to a whole number of samples. This will give you a very limited
      resolution frequency wise. On thing is to round properly, that helps,
      but its still out of tune, the other is to upsample within a poly~ to
      get a better resolution. I tried to get a sort of interpolation by
      varying the feedback length every x loops by one sample...
      But as I look at your patch ,you don't calculate the delay at all...
      The delay will determine the pitch in the karplus strong...
      Stefan
      --
      Stefan Tiedje------------x-------
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    • Oct 27 2006 | 9:07 am
      Quote: Stefan Tiedje wrote on Fri, 27 October 2006 01:21
      ----------------------------------------------------
      > But as I look at your patch ,you don't calculate the delay at all...
      > The delay will determine the pitch in the karplus strong...
      >
      > Stefan
      uhm, of course i calculate the delay!, take another look :)
      but i have the solution allready -> teeth~ (thanks roman!)
      the only point with teeth is that the feedbackline is inside the object so you can't manipulate it, with a filter for instance
      poul
    • Oct 28 2006 | 1:37 pm
      poul wrote:
      > uhm, of course i calculate the delay!, take another look :)
      yeah, got it...
      but you can't get it shorter than the vector size... And you don't need
      to compensate, as if the delay is longer than the vector size, it will
      be correct...
      I looked at my solution and I stuck with tapin~/tapout~ for the same
      reson as you did (a filter in the feedback)
      But I used a simple onepole~ and put all into a poly~ with vs 8. That
      way I got reasonable good tuning even in the high range. And didn't need
      to have the complete patch at that expensive vector size...
      Stefan
      --
      Stefan Tiedje------------x-------
      --_____-----------|--------------
      --(_|_ ----|-----|-----()-------
      -- _|_)----|-----()--------------
      ----------()--------www.ccmix.com