"patch bay"

A 'box' that uses wiring cords to route signals, one at a time each by a seperate cable, between a set of outputs and a set of inputs. The 'box & cables' these days may be real for analogue signals or 'virtual' - simulated in software that usually works for digitised (or analogue converted to digital) signals.


"dbx two-channel compressor/limiter "

dbx - it's easiest to look that up on Wiki - http://en.wikipedia.org/wiki/Dbx_%28noise_reduction%29

2 channels - obvious

http://en.wikipedia.org/wiki/Dynamic_range_compression

also usefully read http://en.wikipedia.org/wiki/Loudness_War

All you have to do is copy and paste the links...