The Waves C6 multi-band compressor is a comprehensive upgrade to the popular C4 with the addition of two floating frequency bands and side-chain capability. It can be purchased separately or as part of the Mercury or SoundGrid Pro bundles. The GUI is standard Waves fare—lots of small-value boxes, several faders and a rather lovely multicolored DynamicLine graph representing the frequency bands, ranges and compression activity.
In use, the C6 does everything that you’d expect and much more. There is so much control available that almost any dynamic task imaginable is achievable. In the studio, I found that the C6 copes well with unruly frequencies within drum overheads, pianos and vocals (de-essing in particular). It can be used as a clean-up tool for nasty bits of spill without sounding unnatural or overly gated. The side-chain function enables the mixer to play about with creating space within the track in just the right place in the spectrum. Dance mixers will love it.
Front-of-house engineers will find that the C6 is capable of reining in those frequencies that cause problems in the live arena, several at a time. It works as a dynamic EQ in that respect. I imagine that post production will be an area where the C6 sees a lot of use and where the side-chain facilities will shine. Ducking background material under a voiceover is common practice in post, but the C6 side chain means that only the vocal frequencies (or a part of them) can be ducked, allowing the side-chain source to sit in the track more comfortably.
Mastering engineers will find the non-side-chain use of the C6 extremely useful as well, especially the floating bands. In mix mode, I had great fun playing with the side chain; dipping and boosting overheads and ambience with snares and kicks, making strings, guitars and synths soar in vocal gaps and just generally making sounds interact with each other! In fact, I like the floating bands so much that I think Waves should make a C2 as well (a C6 without the C4 part, just two floating bands and the side chain).
The C6 doesn’t really have a “sound” of its own, and that’s a good thing. It’s a dynamic tool, and I have plenty of other toys for imparting sonic character. As a powerful multi-band compressor/dynamic EQ with side chain, the C6 (price recently reduced to $250 Native and $500 TDM) is a fantastic plug-in, highly flexible and useful for a multitude of tasks across the pro-audio spectrum.