Residual output - outputs the difference between the original and processed signals (suppressed hum)
Frequency Type - sets the base frequency of the hum to be removed. The two most common base frequencies that cause hum are 50 Hz (Europe) and 60 Hz (U.S.). Other base frequencies can be selected by choosing the 'Free' option.
Digital DSP:enables linear phase filters
Base frequency (Hz)- this slider is only enabled when the Frequency Type is set to Free
Filter Q - controls the bandwidth of filters for base frequency and harmonics
Enable highpass filter:allows high frequencies to pass while attenuating lower frequencies.
Highpass frequency(Hz)- sets the cutoff frequency for the filter
Highpass Q - sets the bandwidth of the highpass filter
Enable lowpass filter:allows low frequencies to pass while attenuating high frequencies.
Lowpass frequency(Hz)- sets the cutoff frequency for the filter
Lowpass Q - sets the bandwidth of the lowpass filter
Num Harmonics: select the number of harmonics that need to be removed (1-8)
Linking Type: here you can choose to link the gain/suppression of all of the filters, none of the filters, or odd/even filters
Harmonic slope - when harmonics are linked, this controls the slope of the gain/suppresion. As the harmonic order increases the gain/suppresion level resolves closer to 0 dB.
Harmonic even/odd slope - when linking type is odd/even, this allows you to control the amount of gain/suppression for both odd and even harmonics
Filter DC Offset: this removes the DC (direct current) offset that is caused by the imbalance that sometimes occurs in A/D converters. DC offset is exhibited by the waveform appearing above or below 0 dB.
Harmonic gains (dB): gives numerical readout of gain settings in dB. You can also manually type in your gain settings for any of the harmonics.