Marketed under the United Plugins ‘umbrella’, Soundevice Digital’s Mastermind plug‑in aims to provide a selection of tools in a single, uncomplicated GUI so as to make mastering your mixes easy. A typical basic mastering chain might include EQ, compression and limiting, but Mastermind does things a little differently. Instead of conventional compression, for example, we have the one‑knob Optimizer, a kind of ‘secret sauce’ process that lifts detail out of a mix while also making it sound bigger. To my ears, this sounds like a combination of dynamics processing and spectral reshaping. For EQ, there’s a simple two‑band shelving EQ with switchable frequencies, for gentle tonal shaping, and this is based on an unnamed classic American analogue equaliser, and has variable tube‑style saturation should you wish to add some warmth at this stage. If you need to benchmark an existing mix, there’s also a Match EQ facility, and at the end of the chain the limiter has adjustable saturation — yet another opportunity to add character. Finally there’s a Stereo Width control to narrow or widen the stereo image.
The GUI is divided into logical sections and, except for the adjustable input gain control, each section has its own on/off button; there’s also a master bypass. A spectrum display at the top of the screen shows the signal both pre‑ and post‑limiter, in addition to the input signal. Output metering shows the stereo levels alongside the limiter’s gain reduction. Clicking the Soundevice Digital logo takes you to their website, from which you can download the user manual.
Mastermind does a good job of adding detail and weight to an already good‑sounding mix.
In use, Mastermind does a good job of adding detail and weight to an already good‑sounding mix, and the EQ works nicely for overall tonal balancing. To use the Match EQ there are two learn buttons, one for the reference source and one for your track. This works in much the same way as other matching EQs: you learn the profile of your source for several seconds, then learn your own mix’s profile, and the software calculates a complex EQ curve to force the spectrum of your mix to match that of the reference.
How effective this process is generally depends on how similar the types of material are to start with, and in my experience using lower settings of the Match control can sound better than aiming for a 100% match. I found the Optimizer sounded best set at around the half‑way mark, at which point it lifts out low‑level detail to make the mix sound richer and more interesting, while the tube and saturation stages are good for adding a subtle warmth without sounding too obvious. The limiter is effective in gaining a little more level, but it’s probably a good idea to insert a loudness metering plug‑in after Mastermind, since it doesn’t have one of its own; without one, it’s easy to find yourself overusing the limiter and delivering ‘congested’ mixes that most streaming platforms can end up turning down!
Mastermind might not have the forensic EQ or complex compressor chains of a real‑life mastering suite for fixing more complex problems, but if you just need to flatter an already decent mix and then bring it up to an appropriate level, this is a good‑sounding collection of tools. It’s easy to use, and it’s actually pretty effective. In fact, as a quick and easy solution to mix polishing, Mastermind has much to commend it.