The STEM Mix Matrix & Master Compressor was concieved of in the spring of 2019, after a phone call from Danish producer, Carsten Heller, giving me some input on a work flow solution. It went through a few revisions, before it settled into this form.
Unit features 4 set of stereo inputs ( 8 channels in total), inserts on each channel, and a master compression section. Originally, I had it drawn up for more, but I wanted to keep it as a simple STEM mix hub, and also future proof it for a stepped version.
Each stereo input is split into an audio mix buss, going straight to the busscompressor, and a sidechain mix, buss, going to the side chain circuit of the compressor.
THE SIDE CHAIN MIX MATRIX
The sidechain mixer and the audio path mixer have separate level controls, so you can balance one mix going into the comp, while doing a completely different mix for the compression trigger circuit.
The differences done on the side chain mix can be subtle, like jacking the drums up a few dB, or taking down an element - or you can go to extremes, like removing elements completely, or leaving just one element in.
Having the ability to tweak the two mix paths hands-on, and make creative choices on-the-fly, as changes to one affect the other, almost makes it feel like you are playing the unit as an instrument.
In addition to the separate mix paths, each STEM has a relay controlled, fully balanced, stereo insert point, so you can patch in your favourite hardware in the mix path.
MASTER COMPRESSION & INTEGRATION
Compression is a VCA based design, tweaked to integrate perfectly with the Side Chain Mix features, and SC Mix inject.
It features 4 ratios, and a Side Chain high pass filter, as well as a suitable range of attack and release times, geared towards master buss compression duties, and stands on the shoulder of my experience with VCA compression circutis and previous designs.
..and if you get lost tweaking your SC Mix blend, theres a listen feature, and a compression bypass function as well.
Prototype in action on youtube here