You may have already heard of Trackspacer, its considered to be a bit of a secret weapon for creating space in a busy mix or where frequencies clash. It works by analyzing the frequency content of your mix and the track you want to create space for, and applying a reverse EQ to the main mix, creating the space for the track(s) you want.
Trackspacer splits the source signal in 32 bands and analyses them individually. Then, it reverses the result and applies a 32 band EQ to duck exactly the same frequencies that the source needs... and in real time! That's why it's much better, transparent and easy to use than regular compressors, it's all about detection.
Trackspacer regularly features in "Plug-ins that will improve your mix" type lists from pundits and professionals. well worth checking out.
And, its on sale for this week at a 26% discount £45.95 - usually £62.20 via PluginBoutique.com