FreqTweak

FreqTweak is a tool for real-time audio spectral manipulation and display. It is free software, available under the GNU General Public License. FreqTweak can (and is supposed to) be connected to other audio software using the JACK Audio Connection Kit.

FreqTweak is FFT based, and supports up to 4 channels. An FFT analysis is applied to audio channel, and every individual band can have a different effect applied to it. In version 0.6.1 the following effects are available:
* EQ cut/boost
* Pitch scaling
* Gate
* Compressor
* Delay
* Limit
* Warp

External links

* http://freqtweak.sourceforge.net/