Audio Difference Signals with Audacity

Hi

Anyone ever created a method to create audio difference signals from stereo music files? Left minus Right and Right minus Left.

If so a tutorial could be helpful to myself and others.

Thanks In Advance,

Bri

Try this plug-in: http://wiki.audacityteam.org/wiki/Nyquist_Effect_Plug-ins#Channel_Mixer
Instructions for installing: http://wiki.audacityteam.org/wiki/Download_Nyquist_Plug-ins#Installing_Plug-ins