i dont know the technicalities for sidechaining etc, but i picked up a Sonalksis SV315 comp and theres a sidechain button on the side.

once i grouped the subbass and the kick and inserted the comp, the difference was RIDICULOUS.

before my tunes never had low-whumf, and one of the presets on the SV315 along with the sidechain function makes it infinately bigger.

pm if you would like to know more ;)