Modeling guitar distortion in Matlab 1.1 2006/12/18 02:38:39.993 US/Central 2006/12/20 16:21:06.660 US/Central Brent E. Stephens brents@rice.edu Neil K. Narayan narayann@rice.edu Rob Smith rob@rice.edu Barron D. Stone barron@rice.edu Brent E. Stephens brents@rice.edu Neil K. Narayan narayann@rice.edu Rob Smith rob@rice.edu Barron D. Stone barron@rice.edu distortion guitar matlab An implementation of distortion in Matlab A very simple type of guitar distortion can be done with clipping of the signal. This is where a threshold value is set, and if the signal ever increases above this value, it is clipped off. This type of distortion adds a "fuzzy" sounding distortion. As is obvious from the picture of the frequency-domain effects of clipping, clipping the signal creates a more complex signal by adding more frequencies.

Distorted Sine Wave A picture of a sine wave after it has been processed with the Matlab function below

FFT of a distorted sine wave The Matlab code that implements this algorithm is also very simple:

function [output]=fuzzy(sound, amount)

norms = norm(sound);
output = sound/norms;
amount = (1- amount)/100;

for i = 1:length(output)
    
  
  if ( output(i) > amount )
    output(i) = amount;
  end

  if ( output(i) < -amount)
     output(i) = -amount;
  end
 
end
 
output = output*norms;