Utilizing compression ratios

We now know that a compressor's threshold determines the point at which the…compressor activates, but how much the signal is actually compressed is…controlled by a parameter called ratio.…A compressor's ratio control determines how much any signal over the threshold…is attenuated and is generally expressed as a larger number over one, for example, 4:1.…Many times compressors will express the threshold and ratio relationship using…an X-Y graph called a transfer curve.…A transfer curve graph plots the signal's input into the compressor on the X…axis and the signal's output on the Y axis, so you can easily trace different…scenarios just by following the line.…

The kink in the line, called the knee, is the point at which the compressor's…response becomes nonlinear.…That is to say, the input and the output do not match because the compressor is…now reducing the gain of any signals over the threshold by the amount defined by the ratio.…A ratio of 1:1 means no compression takes place, and lower ratios may be barely visible.…