Forums > MaxMSP

oscbank~ : How keep phase sync in simple additive synthesis ?

February 27, 2010 | 12:08 pm

hi,
A patch is better than a complicated explanation, please see patch attached here.

I use oscbank~ as a simple harmonic additive synth, and when i move enough the fundamental frequency (but not so much) of this synth, i loose the phase synchronization between the harmonics…
Is there a way to keep the phase synchronization ??

That’s a big question for me,
Thanks a lot,
Alexandre

P.S: by the way, if someone can really tell the difference between the objects oscbank~ and ioscbank~, i didn’t get it… (what interpolation?)

P.P.S: With this patch you can play with TouchOSC if you have it. (the layout to upload is in the folder)


February 27, 2010 | 12:58 pm

It looks like you aren't generating the same waveform in both [oscbank~]s, so of course the difference will be other than zero:

[attachment=125876,129]

Attachments:
  1. oscbank.png

February 27, 2010 | 5:59 pm

No, the thing here is that (i just realized it), the scheduler "in Audio interrupt" must be ON. (and also "Scheduler in Overdrive" ON, and "Overdrive" ON, of course)… now the two [oscbank~] make EXACTLY the same sound.

The true problem is that the phase synchronization between the harmonics in oscbank is going away* (in a time which looks proportional to the intensity with which you move the frequency)… the "framesync 1" message doesn’t change anything.

How can we make oscillators that are really phase synchronized ??

* until you initialize the phases with the "clear" message


March 1, 2010 | 6:57 pm

Anyway, i feel that an additive synth can be achieve also by using saw~>resonators~ , and resonators~ with 200 resonant filters seems 70 percent more efficient than oscbank~ with 200 oscillators…


Viewing 4 posts - 1 through 4 (of 4 total)