Used in conjunction with other features this parameter can afford the mixer a variety of complex effects such as ramping in of background music. The advantage to this setting is that it allows for ramping and input gain is the same every time a gate first comes on. The SMX output compressor is different than a conventional output compressor because you can actually choose which inputs participate in output compression. This can be a valuable tool if you have microphones on some inputs and a playback source on other inputs. You might reasonably expect that the playback source such as a CD or tape player will no output level which would require compression, so you might not configure those inputs to participate in the output compression scheme.
Threshold is the sensed output level above which the compressor begins to actuate.
Release Time is the time in seconds to release compression at a slope of seconds per 10 dB. The range is 0.2 to 30 seconds for each output. The gate count feature attenuates all gated on inputs by a predetermined amount when more than one input is gated on. The purpose is to prevent feedback problems due to multiple open mics. Amount is how much attenuation per additional open mic. This feature is sometimes called a filibuster control because it can make the mixer work in a first come first served manner by limiting how many inputs may gate open simultaneously.