here's a hack using comb filtering and pitch-tracking:

negative feedforward values reinforce one set of harmonics, positive reinforce the other: https://ccrma.stanford.edu/~jos/pasp/Feedback_Comb_Filter_Amplitude.html

i wonder what "the odd harmonics" of a spectrally complex sound would be. :)

wouldnt you come closest with waveshaping?

oh yeah just apply the appropriate chebyshev polynomial to the signal; there's a tutorial on that, synthesis tute #5

Hi, thx but that's not clear to me. Comb trick is not really clean and I didn't find my answer on Tuto 5. Let say I have a signal, I know the fundamental, how to change balance between odd and even harmonics ? Could you show me in a concrete patch ? Thx. ps : I'm looking for something like symmetry parameter on 259 buchla (or furthrrrr or other complex oscillators).

OK, in the previous patch the way I calculated the delay for the comb filter was out by a factor of two, so it didn't really do anything. Here's a better example, with comb filter params scaled for your convenience:

edit: pull down the gain slider by 20db before turning on the audio ;-)

haa yes. that's really nice. now I'll try to understand what's happen… thx a lot.

thats great floating point, simple but clever.

reminds me on spectral inversion by ringmodulation or fft-based dc blocking. :)

(i almost abbreviated you "fp" but somehow i think this could be a bad idea in this thread.)

actually this method does need some dc blocking -- there's a huge dc offset (0hz is an even harmonic) introduced that should be dealt with

I used to do something like in a very old patch. It's been a while that I didn't compare those objects but If my memory is correct I remember that the external resonators˜ from the CNMAT sounds far better, is much more efficient, and is better suited for what you (and me) want to do, than the comb˜ object or any other filtering object in max.

Also you need a pitch tracker for the fondamental of your sound ? By the way what is the best pitch tracker for Max in 2017? (I'm just coming back from my cavern right now had a big max break since 2015 ) In 2014 it was still a pitch tracker i had from FTM externals who was tracking my violins more accurate than other more standard max objects. If you need it i can upload.