In rough terms, a compressor can be described to consist of two circuits; the level detection circuit and the gain reduction circuit.
Sidechaining is all about giving you control over the signal that enters the detector circuit and ultimately drives the gain reduction. The most common techniques involve filtering the sidechain, or assigning a different audio source to control the compression. Compadre allows the combination of both.
Compadre offers plenty of sidechain filtering capabilities with its low- and highpass filters and 9 preset filter models. Sidechain filtering does not alter the spectrum of the output, instead it changes which frequencies triggers the compression and allows you a great deal of control of how the compression will sound. For example, if your track needs a smoother sounding compression, selecting the "Smooth" filter will filter out the very high & low frequencies of the sidechain signal that could otherwise stress the compression.
Compadre has an extra set of inputs allowing you to route any signal to the sidechain. This can be used for a vast amount of creative and experimental applications, but it also has use for a range of traditional and well proven production techniques; such as "ducking" & "de-essing". Ducking is a useful technique when dealing with overlapping frequencies in a busy mix, but often it is also used creatively in dance music by letting the kick drum trigger compression of bass and synths for pronounced rhythmic impact. Compadre works great for those tasks.