Alexandre,

I have translated a PD patch (see the last graph on this page) and it is modulating AND responding to frequency changes. See if this does the trick for you (doesn't sound exactly like your SC code, but I think some fiddling with modulation index can be useful):

Step imp; // now I am using an impulse to generate sound after calculating stuff from phasor/sinosc

Phasor carrier; // Miller said to do so ;)

SinOsc modul; // a phasor as carrier, a sinosc as modulator

Gain g; // this object serves only to sum the signals

1 => g.op; // op number 1 is sum.

400 => carrier.freq;

201 => modul.freq;

1 => float ind => modul.gain; // so, modul. signal * index + carrier signal.

imp => dac; // impulse is actually generating sound

carrier => g => blackhole; // both generators go through a Gain object an then to the blackhole

modul => g; // so that they only lend data to the Impulse generator

while ( true ) { // this loop includes a timed function only to show that this stuff responds to changes into carrier's frequency

    now + 1::second => time later;

    while (now < later) {

        Math.cos(g.last()) => imp.next; // i am running this through a Cosine function since Phasor is a ramp (let's smooth that)

        1::samp => now;

    }

    if ( maybe ) 20 + carrier.freq() => carrier.freq;

    else -30 + carrier.freq() => carrier.freq;

}

Please notice that Miller Puckette's approach includes using the phasor as *carrier* and sinosc as *modulator*, so that we can separate phase treatment and wave generation (phasor + cos). I am using an Impulse generator in order to be allowed to pass the resulting signal through the cosine function before sending it to DAC.

Keep trying...

Em dom, 4 de jun de 2017 às 03:34, Alexandre Torres Porres <porres@gmail.com> escreveu:

2017-06-04 2:35 GMT-03:00 Alexandre Torres Porres <porres@gmail.com>:

It's not easy to explain, but you found the magic number/formula that makes Frequency modulation sound like Phase Modulation. 

Actually, I shouldn't have said this, I don't wanna give you the idea it comes down to this, but there are just too many details I didn't want get into, sorry. What I can say is that you got pretty close, not 100% there yet, and that is not as simple as just doing this every time, it gets more complicated.

Sorry again for not getting into the math and everything. What I'd like to add is that people use phase modulation instead of trying to replicate it via frequency modulation cause it's just more convenient to do directly via phase modulation if you want it to behave like that.

cheers

--

Jean Menezes da Rocha

Compositor

Professor

Doutorando em Música pela Universidade Federal da Bahia