TrackSpacer

TrackSpacer is an audio plug-in (available in VST, AU, and RTAS formats / Mac and Windows) that creates space in the mix for an instrument, voice, or other audio by performing automatic, multiband equalization on a channel. In real-time it analyzes the audio frequency content in a track/bus via sidechain, and applies an intelligent 32-band EQ to subtract those frequencies from the channel/bus where TrackSpacer is inserted.
In other words, it gives room or space to a certain track by reducing its frequencies on another track in real time.
We've developed this very accurate and difficult to tweak algorithm along with Xavier Oudin.

TrackSpacer is versatile and can be used in many different situations. But for illustration let’s look at two common examples where it can solve complex EQ problems. If the kick and bass are competing for space, insert TrackSpacer in the bass channel and have it listen to the kick. Then you can easily fine-tune TrackSpacer so that it only subtracts from the bass signal the frequencies that help define the core sound of the kick everytime it hits. The result is that both are heard more clearly.
If you need to create room for the vocal in a busy and dense mix, route all the competing instruments to a bus, insert TrackSpacer, and have it listen to the vocal. As the performer talks or sings TrackSpacer selectively subtracts the vocal’s audio frequency energy from the bus signal. This gives the vocal a lift without a reduction in the overall volume level of the instruments.
It's very effective on voiceovers where the voice has to sit on top of the background music, it just makes more room for it and you can hear how the music is not disturbing the voice at any time.