FM Synth devs

[DavenH]

Hi, I've done my bit searching but can't seem to find a straight answer - how does feedback work?

I know I'm missing something from my equations, but I don't know what. Is it only possible with programming, or can a feedback waveform be rendered with such a program as Maple or Mathematica with the right formula?

Perhaps all my questions could be answered if someone would fix these formulae - I'm just trying to do the math for a 2OP synth for starters:





Obviously the feedback parts - mod[1,1] and mod[2,2] aren't there because I don't know where to put them.

Any help would be most appreciated

[Hernan]

I think there was a Sound-on-Sound article on FM where they explained the types of sidebands generated by modulating a sine wave. If I remember correctly they said that you cannot analyze the feedback mathematically.

In the DX7 manual they handwaved the whole thing saying something like 'feedback sounds like white noise', and that was it.

I don't understand the formulas. Are you modulating op1 by op2 and vice versa?

BTW, you may try asking this question on the DSP/development forum. Lots of brainpower there.

Best,

Hernan

[DavenH]

Thanks for the advice.