High-Pass Filter

High Pass Filter passes frequencies above its cutoff frequency and attenuates frequencies below its cutoff frequency. This effect can therefore be used to reduce low frequency noise.

Accessed by: Effect > High Pass Filter...

Sound below the cutoff frequency is not eliminated but increasingly attenuated as the frequency falls further below the cutoff. The steepness of the attenuation is set by the rolloff value. For example, with a rolloff of 6 dB per octave, the sound decreases by 6 dB for each octave below the cutoff frequency (an octave below is half the frequency).

Rolloff [dB per octave]

Higher rolloff values give a sharper attenuation of frequencies below the cutoff frequency.

Filter quality [q] for 12 dB rolloff

If using a rolloff of 12 dB, a (q) value of greater than default 0.7 increases resonance (ringing) of the cutoff frequency.

Cutoff frequency [Hz]

TBP

It is hard to design a pass filter with a sharp cutoff, so the cutoff or corner frequency defines the point at which the audio is reduced by 3 dB. Thus there will also be a small and decreasing amount of attenuation just above the cutoff frequency.

To achieve more attenuation you can run the effect again or use a greater rolloff.