Voxengo has released a beta version of Overtone GEQ, a 7-band harmonic (overtone) graphic equalizer, with multi-channel support (up to 8 channels; host setup dependent; with VST hosts version below 2.3 only 2 channels will be used).
Overtone GEQ implements graphic equalizer by using bell-shaped curves. So, when you boost adjacent bands the overall boost may go over 12 dB. Beside equalizing, Overtone GEQ features an harmonic enhancement module called 'meta tube'.
NOTE: Overtone GEQ is CPU hungry because it uses 7 'meta tubes' - one for each EQ band. This generates a quite complex harmonic distortion.
Overtone GEQ is available as a VST effect plug-in for Windows and it is free. However, this is a beta release and there are several known issues. More information can be found in this topic in our effects forum.