Jeff Rippe has released HyperFilter, a high frequency filter with a selectable cutoff slope of -12, -24 or -36dB/Octave. The filter is useful for removing hiss, crackles and even sampling noise from your audio.
It has 2 controls: cutoff slope and cutoff frequency. The cutoff frequency is variable from 1KHz to 20KHz. The pass-band is flat (Butterworth filter) and has unity gain. The cutoff frequency upper limit is automatically adjusted depending on sample rate (for example, upper limit when used on 22.05KHz sample rate signals is 10KHz).
HyperFilter is available as a VST effect plug-in for Windows and it is free.
