Philip Cunningham

Anapnean, Musician, Rubyist, Scotsman.

SuperCollider & PD: Simple Additive Synthesis

By adding together sinusoids we can begin to create interesting synthethic timbres. Well, more interesting than plain sine waves. I’ve included examples of how to do this in PD and SuperCollider. I attempted to do this in both languages to get a better feel of the differences and similarities between them.

PD feels sluggish by comparison, manually connecting lots of [osc~] objects can get tedious quickly. That said, @poperbu, is going to send me some patches that show how to connect things dynamically in PD. I’m looking forward to giving that a try.

SuperCollider, on the other hand, is starting to get really exciting. There are some Ruby-like control structures in there that I’m really interested in exploring further.

Pure Data:

PD Additive Synthesis

Download

SuperCollider:

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// =====================================================================
// additive synthesis:
// building richer sounds from sinusoids
// =====================================================================

// Declare variables
var fund, synth, freq, amp;

// Fundamental frequency
n = 440;

// Create an array of overtone frequencies
freq = Array.new(10);
f = (1..10).do {arg i; var val = (i*n); freq.add(val) };

// Create an array of 10 random floats
a = { arg num = 10;
  var rand_nums = Array.rand(num, 0.0, 1.0);
  rand_nums;
};

// Set amp to an array of amplitude values
amp = a.value;

// Make some sound
{Mix(SinOsc.ar(freq,1,amp))*0.1}.play

EDIT: Another, more elgant way:

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(
{
  var n = 10;

  var wave = Mix.fill(10,{|i|

      var mult= 1.0.rand;

      SinOsc.ar(440*(i+1))*mult

    });

  Pan2.ar(wave/n,0.0);

}.play;
)

EDIT: Another, even slicker, way!

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(
var n = 10;
var fund = 440;

var arr = Array.rand(n, 0.0, 1.0);
var freq = fund*(1..n);

{Mix(SinOsc.ar(freq,0,arr))*0.1}.play;
)