Intro to Spectral Gate in Final Cut Pro
Spectral Gate is an unusual filter effect that can be used 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 controls. The signal ranges above and below the defined band can be individually processed with the Low Level and High Level controls and the Super Energy and Sub Energy controls. See Use Spectral Gate in Final Cut Pro.