Jeff Rippe has released SubFilter, a steep slope subsonic filter with a selectable cutoff slope of -12, -24 or -36dB/Octave. It is useful for removing thumps, bumps and low frequency rumble noise from your audio.
The filter has 2 controls: cutoff slope and crossover frequency. The cutoff frequency is variable from 10Hz to 200Hz. The passband is flat (Butterworth filter) and has unity gain.
SubFilter is available for Windows as a VST effect plug-in and it is free.
