Gain Reduction
Definition
The amount by which a compressor, limiter, or gate reduces the level of a signal, measured in decibels. Displayed in real time on a gain reduction meter. The visual representation of how hard a dynamics processor is working.
In Simple Terms
How many decibels a compressor or limiter is turning down your signal at any given moment. The gain reduction meter shows you how hard the processor is working. More isn't always better.
In Practice
A compressor showing 6 dB of gain reduction on a vocal is reducing the loudest notes by 6 dB. A limiter showing 0 dB of gain reduction is not being triggered — the signal has not reached the threshold.