ABSTRACT
An expander’s interface is no more complicated than a compressor’s. As before, there’s a Threshold control to tell the expander which parts of the signal need to be processed, although in this case it’s signals below the threshold that have gain-reduction applied to them. The Ratio control adjusts how vigorously the expander turns things down once signals dive below the threshold level. A ratio of 1:1 causes no expansion at all, whereas a higher ratio of, say, 4:1 will dramatically reduce the levels of subthreshold signals. Some expanders even offer a ratio of infinity:1, which effectively mutes any signal lurking below threshold, in which case the processing is commonly referred to as gating, and some specialized expansion processors called gates offer only this most extreme ratio.
