FM Modulation
by mmadejster
Interesting thing happens when you feed output of the one oscillator into the other oscillator , we obtain new kind of synthesis, what is referred to as a FM Synthesis or FM modulation.
In the above example, the sine wave(the big one) is modulated by the square wave (the tiny one), So on this case the Sine Wave is the carrier, and the Square wave is the modulator.
The complex sounds are formed by so-called sidebands, that are created above and below the carrier signals.
In this session 3 sine oscillators are connected in series have been modulating each other. More precisely 3 analog filters self-oscillating. The Blue is the FM modulation,
I have uploaded video of the FM Modulation of my system.
Marek Madej 
