Smoothing out pitch change in delay feedback

    Aug 29 2012 | 12:31 pm
    Hello everybody,
    I'm not new to max/msp - and thought I had a working brain, but apparently not...
    I'm looking for a way to make a pitch-change in a delay feedback run silkily smooth.
    It's a simple patch, but despite trying every method of pitch shift and delay size, there is always a 'pulse' in the delay (especially noticeable when the sound file stops....)
    Is there a better way to do this - or am I always going to be hitting a window-size issue which makes this pulse happen?
    The desired effect it a constant cascade of falling pitches, but totally smooth.
    Thanks in advance....
    Lee Morgan

    • Aug 29 2012 | 12:49 pm
      hth aa
    • Aug 29 2012 | 2:34 pm
      Thanks Andrea - happy to get those tools, but it doesn't seem any better than tapin/out in this particular patch.
      I'm about to try 2 delays with phasor to swap between the two, and fiddling with delay times and fft sizes, overlapping sizes....but maybe that's a dead end?
    • Aug 29 2012 | 6:03 pm
      Hi Lee have you checked out our "good buddy Sam" at Delicious MaxMSP on youtube? He has a good collection of both fun and didactic tutorials, including delay-based pitch variation; I'm sure you'll find something you can hack.
    • Aug 29 2012 | 7:18 pm
      Yes....but it's not really delay-based pitch shifting I'm trying to do, it's combining a delay with pitch-shiftiing on a feedback loop that I'm trying to do....the delay itself is (and I think needs to stay) static...
    • Aug 30 2012 | 4:52 pm
      I think you're running into the reality of digital audio. Each individual sample has no pitch; pitch is an emergent property of a group of samples. You can't really shift the pitch until you've collected a group of samples.
      I made patch called harm-gran~ in the CNMAT downloads that does pitch shifting on relatively short windows. But there are still audible artifacts. gizmo~/pfft~ also imposes it's own delay. In the time domain, there really is no pitch shift without some time shift.
    • Aug 30 2012 | 8:37 pm
      Well now you see, this is why I love max/msp and it's community: helpful, unpatronizing explanations.....we all learn, and move on. Thanks doc!