Quote Originally Posted by rounser
I thought you sidechain a compressor to a ducker, so your bass ducks your kick when the compressor gets triggered and goes into the attack bit.

Never done it before though...it's just what I remember. It seems to make sense...is that right?
In most cases, a side chain is usually used to attenuate other sounds when the kick hits to give a pumping effect. Mainly this is used to attenuate the bass. Personally i tend to use quite harsh sidechaining on a lot of instruments to get a really drastic pump effect.