Sennheiser VSM201 Vocoder Emulation in SuperCollider

README.md

Came close with this one but couldn't quite get anything as clear as the original.

Audio demo of the following code: https://www.dropbox.com/s/ejuwpd5pp60pn3r/vocoder_sc_demo.mp3?dl=0

Source audio files along with technical documents describing the operation of the original are here: https://www.dropbox.com/sh/6znkjoy2p1ejk42/AAC_i_359F-jRznPfv8-yEN6a?dl=0

vocoder.scd

Server.default.options.numWireBufs = 1024;

s.boot;
Buffer.freeAll;

~b0 = Buffer.read(s, "/Users/xavriley/Dropbox/Public/sounds/sennheiser_demo-1.wav");
// ~b0 = Buffer.read(s, "/Users/xavriley/Dropbox/Public/sounds/ben.wav");
~b0 = Buffer.read(s, "/Users/xavriley/Dropbox/Public/sounds/hbfs/working.aiff");
~b1 = Buffer.read(s, "/Users/xavriley/Dropbox/Public/sounds/sennheiser_demo-1-wet.wav");
~b2 = Buffer.read(s, "/Users/xavriley/Dropbox/Public/sounds/sennheiser_demo-1-wet-noise.wav");

~b0.play;

{ PlayBuf.ar(2, ~b0, loop: 1, rate: 0.5) }.play

(
var vocoder;
vocoder = (
SynthDef('sonic-pi-fx_vocoder', {
	arg out_bus = 0, in_bus = 0, note = 53, pan = -1;
	var voicedCarrier;
	var replacementSound;
	var snd, numBands, bandFreqs, bandMuls, carrier;
	var perc, chain;

	numBands = 20;
		bandFreqs = (0..numBands - 1).linexp(0, numBands - 1, 50, 8000);
		//bandFreqs = [140,240,350,450,560,690,820,990,1150,1380,1590,
		//	// K12, ...
		//	1850,2190,2550,2900,3400,4000,4800,5800,7400];
		bandMuls = [0.6,0.6,1.5,1.5,1.5,1.5,1,1,1,1,1,1,1.5,1.5,1.2,1.2,1.2,1.2,1.2,1.2];


	// modulator (i.e. voice) is taken from the right channel of input
	snd = In.ar(in_bus+1,1);
	// snd = PlayBuf.ar(1, ~b0, loop: 1, rate: 1);

	// voicedCarrier = In.ar(in_bus, 1);
	voicedCarrier = In.ar(in_bus,1);
	replacementSound = LPF.ar(HPF.ar(WhiteNoise.ar(mul: 1), 3000), 8000);

	// FFT based voiced/unvoiced detection
	chain = FFT(LocalBuf(1024), snd);
	perc = SpecPcile.kr(chain, 0.9).explin(2000, 8000, 0, 1);

	carrier = SelectX.ar(perc.lag(0.2), [voicedCarrier, replacementSound]);
	// carrier = replacementSound ! 2;


	// carrier = SelectX.ar((ZeroCrossing.ar(snd).cpsmidi.lag(0.02) > 2500.cpsmidi).lag(0.02), [voicedCarrier, replacementSound]);
	// carrier = WhiteNoise.ar();


	snd = Amplitude.ar(BPF.ar(snd, bandFreqs, 0.05, bandMuls), 0.01, 0.05);
	snd = BPF.ar(carrier, bandFreqs, 0.1, bandMuls) * snd;
		// snd = carrier * snd;

	snd = snd.sum;
	// snd = snd + (ToggleFF.ar(LPF.ar(snd, 100, 0.05)) * 0.01);
	snd = snd * 30.dbamp;
	// snd = Mix.ar([snd, carrier * 0.3])
	// snd = Limiter.ar(snd);
	// snd = MoogVCF.ar(snd, 5000, 0.25) ! 2;

	//snd = BitstreamPitchCorrection.ar(snd, target_note: 64);

	Out.ar(out_bus, Pan2.ar(snd, pos: pan));
}));

vocoder.add;

// vocoder.writeDefFile("/Users/xavriley/Projects/sonic-pi/etc/synthdefs/compiled/"); // change this path to point to Sonic Pi on your system

)


x = Synth("sonic-pi-fx_vocoder");

y = Bus.audio(s, 2);

({
	Out.ar(y, [Splay.ar(Saw.ar([60, 64, 67].midicps), spread: 0), PlayBuf.ar(2, ~b0, loop: 1, rate: 1)]);
	// Pan2.ar(PlayBuf.ar(1, ~b1, loop: 1), 1);
}.play;)

x.set(\in_bus, y.index);
x.set(\pan, -1);
x.set(\in_bus, 0);