Nyquist Distortion script for Audacity

I didn't write this script but I'd like to point it out as it answers a question asked several times in forums, "Where can I find a distortion plugin for Audacity" So here's a link to the script. It takes a root of each discrete value of the sound giving it a distorted sound. Here's an example of the 6th root (n = 6) of a recording then processed with low-pass filter (to remove harmonics above nyquist frequency) and Bass Boost.

 Enjoy.

Guitar Distortion in Python

I've written a Python program that computes the arctangent of every discrete value of a wave file. The arctangent is a non-linear function therefore the amplification of the input signal will also be non-linear resulting in a distorted sound. This script is perfect for performing distortion on a pre-recorded guitar sample.

Click here to download the script.

I recorded a clean guitar sample and then processed it with Audacity and distort.py. I did it in the following steps:

• Apply Audacity's high-pass filter with settings: Rolloff=6dB , Filter Quality = 0.7, cutoff frequency = 1001HZ
• Export the file as a 16-bit stereo wave at 44100HZ.
• Close Audacity
• Process the output with distort.py 
• python distort.py clean.wav distorted.wav
  
• Add the following code to your EQCurves.xml file (located at <user name eg. root>/.audacity-data, under Linux).
• Open Audacity
• Import the output file from distort.py into Audacity.
• Go to the "Effect" menu and apply the Equalization effect, select the distortion curve.
• Go to the "Effect" menu and apply the BassBoost effect with settings : Frequency = 200HZ , Boost = 12dB
• Repeat applying BassBoost as much as you like.
• Your final recording should sound something like this.

Enjoy :)

Links:

• http://music.columbia.edu/cmc/music-dsp/FAQs/guitar_distortion_FAQ.html
• http://soledadpenades.com/2009/10/29/fastest-way-to-generate-wav-files-in-python-using-the-wave-module/
• http://quitte.de/dsp/caps.html