If you are looking for useful mixing tools to add to your plugin collection, then the Bittersweet II plugin from Flux is definitely worth a look. It’s a transient modulator, which basically allows you to beef up or smooth out the ‘punch’ or attack of an instrument, which works well on acoustic guitars etc. and is particularly useful for drums.
In terms of compatibility Bittersweet comes in VST, RTAS and AU formats, so will integrate with any professional recording software, and just like the Massey L2007 and CT4, it’s free!
Functionality
Bittersweet gives you a lot of control in a clean and slick interface. The main central control allows you to suppress or enhance transients by dialing it towards ‘sweet’ or ‘bitter’. If you’re looking for a really smooth guitar tone, then the ‘sweet’ side will just give you a lot of that softness. If on the other hand, you are after a really punchy snare sound then the ‘bitter’ side can bring out that initial attack.
Beyond the main control, you also have control over the time period the plugin classes as a transient, and how fast or slow the level ramps up and down either side of it. The most useful feature that not many transient modulators give you, but Bittersweet does, is that for multiple channels you can switch between applying the plugin across all of them (Main), just the middle (Center), or the side signal (Stereo). This is useful for example, when putting the plugin on a stereo drum mix, and you can beef up all the transients using main, or just the snare and kick by selecting the center. I haven’t yet found a useful application for the side setting, however I suppose you could use it in a few hard-panned mastering situations
Usability
For the majority of applications, you can just plug in Bittersweet and dial in the central button, and already it’s probably very close to doing what you need it to. If you do need to tweak how it’s affecting the audio more precisely, then the necessary options and controls are available without getting in the way.
Overall, the plugin is very quick and intuitive to use and it does what you need it to. Give it a go, and let us know how you get on with it.