
Spectral Gate overview in MainStage
Spectral Gate is an unusual filter effect that you can use as a tool for creative sound design.
It works by dividing the incoming signal into two frequency ranges—above and below a central frequency band that you specify with the Center Freq and Bandwidth parameters. The signal ranges above and below the defined band can be individually processed with the Low Level and High Level parameters and the Super Energy and Sub Energy parameters.
To add Spectral Gate to your concert, choose Filter > Spectral Gate in a channel strip Audio Effect plug-in menu. See Add and remove plug-ins in MainStage.

Spectral Gate parameters
Threshold slider and field: Set the threshold level that is used to divide frequency ranges. When the threshold is exceeded, the frequency band defined by the Center Freq and Bandwidth parameters is divided into upper and lower frequency ranges.
Speed slider and field: Set the modulation frequency for the defined frequency band.
CF Modulation slider and field: Set the intensity of center frequency modulation.
BW Modulation slider and field: Set the amount of bandwidth modulation.
Graphic display: Shows the frequency band defined by the Center Freq and Bandwidth parameters.
Center Frequency knob and field: Set the center frequency of the band you want to process.
Bandwidth knob and field: Set the width of the frequency band you want to process.
Super Energy knob and field: Set the level of the frequency range above the threshold.
High Level slider and field: Mix the frequencies of the original signal—above the selected frequency band—with the processed signal.
Sub Energy knob and field: Set the level of the frequency range below the threshold.
Low Level slider and field: Mix the frequencies of the original signal—below the selected frequency band—with the processed signal.
Gain slider and field: Set the overall output level.