Christian Budde and, fellow KVR member, Dalor have released Rubberfilter. The idea sprang from a KVR forum thread entitled million dollar scientific EQ? and now it has its own thread.

Rubberfilter offers four classic filter modes to cut frequencies with up to 384 dB/Oct. It removes frequencies in any audio signal, while providing an additional creative purpose. Rubberfilter has a controllable filter order of 6 dB/Oct up to 384 dB/Oct. At high filter order levels, a psychoacoustic effect appears which is usually an unwanted sound of zips and sweeps, almost as if there is a tone present at the filter's cut-off frequency. Rubberfilter allows you to use this psychoacoustic effect for creative purposes.

Rubberfilter is available as a free VST effect plug-in for Windows.