A function of compressor or limiter, gain reduction refers to the regulation of the amplitude of a signal in order to prevent it from getting too loud, or to keep the signal at a relatively uniform level, or both. In a compressor/limiter, the primary controls that affect gain reduction are threshold and ratio. The ratio control determines how much gain reduction is applied to signals that go over the threshold setting. For example, a ratio of 2:1 will cause a signal that goes 2dB over threshold to be reduced to 1dB over threshold; a signal that’s 10dB over threshold will be reduced to 5dB over threshold, and so forth. To achieve a stable signal without the pumping effect, maximum gain reduction of signal peaks should typically be between 3dB and 6dB.