Skip to content Skip to navigation

Connexions

You are here: Home » Content » Modeling guitar distortion in Matlab

Navigation

Recently Viewed

This feature requires Javascript to be enabled.
 

Modeling guitar distortion in Matlab

Module by: Brent Stephens, Neil Narayan, Rob Smith, Barron Stone. E-mail the authors

Summary: 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.

Figure 1: A picture of a sine wave after it has been processed with the Matlab function below
Distorted Sine Wave
Distorted Sine Wave (clippedsine.png)
Figure 2
FFT of a distorted sine wave
FFT of a distorted sine wave (fftafterdistortion.png)

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;

Content actions

Download module as:

PDF | EPUB (?)

What is an EPUB file?

EPUB is an electronic book format that can be read on a variety of mobile devices.

Downloading to a reading device

For detailed instructions on how to download this content's EPUB to your specific device, click the "(?)" link.

| More downloads ...

Add module to:

My Favorites (?)

'My Favorites' is a special kind of lens which you can use to bookmark modules and collections. 'My Favorites' can only be seen by you, and collections saved in 'My Favorites' can remember the last module you were on. You need an account to use 'My Favorites'.

| A lens I own (?)

Definition of a lens

Lenses

A lens is a custom view of the content in the repository. You can think of it as a fancy kind of list that will let you see content through the eyes of organizations and people you trust.

What is in a lens?

Lens makers point to materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

Who can create a lens?

Any individual member, a community, or a respected organization.

What are tags? tag icon

Tags are descriptors added by lens makers to help label content, attaching a vocabulary that is meaningful in the context of the lens.

| External bookmarks