Tc Native Bundle 3.1 (there is a bug in 3.0 and this feature dos'nt work) add the sidechainer to your kick drum channel, then add a TC Compressor to whatever you want to be squashed by the kick, click the 'key input' on the compressor so its highlighted red. (you may have to reset it everytime you re-open the project) now you can control the amout of sidechain compression by playing about with the 4 main perameters on the compressor, (attack, release, threshold & Ratio) i tend to set them all to the bottom then move the Threshold and ratio up and you can hear the loop (or whatever you've routed through the compressor) sucking in and out of the kick drum, when the kick is taken out completely the source will hop straight up in volume (nice for fills). Anyone have another methods?