The Disintegrator – Random Project Idea Realized

A few days ago I posted this random idea to Twitter

Random project idea: The Disintegrator - Load a track and slowly add more and more harmonic distortion until it is just white noise!

— AudioGrains (@AudioGrainsBlog) May 15, 2014

So naturally I went ahead and built a reasonable approximation using my new Web Audio API powers.

The Web Audio API has a built-in module for creating distortion modules called createWaveShaper which takes two optional attributes- curve and overSample. A null value for curve applies no distortion, whereas an array containing a distortion curve function (like this one – look at distortion curve equations you can see page 74 of this PDF for an equation and matlab implementation.

Creating the waveShaper node is easily accomplished just by calling the createWaveShaper method

VolumeSample.distNode = context.createWaveShaper();

This creates a waveShaper node with a null value for curve. We can add a distortion curve by calling it with the curve attribute.

VolumeSample.distNode.curve = makeDistortionCurve(50);

(where makeDistortionCurve is from the code linked above)

We can then use setInterval to update the curve every 1000 milliseconds to increase the distortion.

setInterval(update,1000);

function update(){

VolumeSample.distNode.curve = makeDistortionCurve(updateIndex++);
}

We then chain our nodes together to connect the source to the destination

source.connect(this.distNode);
 this.distNode.connect(this.gNode);
 this.gNode.connect(context.destination);

Try it out for yourself. Load any track (give it a second to load fully) and listen to it disintegrate. Now I wonder what Michael Gordon’s ‘Industry’ would sound like?
UPDATE: It sounds great!

Javascript Source Code Here