Sledge Hammer Compressor
Dynamic Range Compressor - more compression means a flatter amplitude envelope, giving a more sustained sound
Signal level in dB required to trigger amplitude-envelope modification
Signal level averaging-time in seconds when the signal is coming on ("attack")
Signal level averaging-time in seconds when the signal is going away ("release")
Ratio of output level change over input level change. For example, if the Ratio is 10 ("high compression"), then the output level goes up 1 dB for each 10 dB of input-level increase above the Threshold level.
At high compression levels, it is usually necessary to increase the overall gain so that large (compressed) signal levels are as audible as when the compression is bypassed. This is called "Makeup Gain".Wikipedia page on Dynamic Range Compression