Separate Mid-Side Processing on a Stereo Signal / Matrix COn

Hi Everyone,

I’d like to build my general sound design template out a bit more so that all tracks are routed into a series of Group Tracks that effectively isolate the Mid / Side information from their summed sources so that I can process these signals separately before decoding and printing to an exported stereo track.

As I’m still wrangling with what seems a frustrating lack of explicitly configurable inputs / outputs within Nuendo (due to my inexperience, I’m guessing), I’m finally here to ask the room how they’d set something like this up. Aware of solutions like Voxengo MSED, but would like the experience of having set this up myself with straightforward phase cancellation.

I’m mostly going off this and this for routing guidelines.

Where I’m stumped is I can’t figure out to send the discrete L / R signals out of my stereo source tracks for phase inversion, processing etc. before recombining them in some way.

I feel like I’m running into the problem of forcing the L/R signals to sum before I want them to–e.g. if I create two stereo group tracks with mono children (M.L, M.R, S.L, S.R) and direct route a stereo signal to all four of those, it’s going to send a summed signal to all four of those mono tracks when I really want it to send the Left channel to M.L and S.R, the Right channel to M.R and S.R.

If I instead direct route the stereo signal into just two stereo Group Tracks (M and S), I can use the unlinked panner to collapse the stereo signal of M just fine. But, then I’m stuck with not knowing how to phase invert only the right channel of S before I start bringing things back together.

What combination of Group and FX tracks would you guys use to accomplish something like this?

It’s frustrating, as I feel like I could work into it in Pro Tools pretty quickly, but that I’m unable to make Group and FX tracks take exactly the inputs I want and go where I want afterwards. It’s probably just that I need to make a paradigm shift.

Cheers in advance,


Hey Luca, I cannot answer your question directly. I always found this setup complicated to do in a DAW with native routing. Why don’t you use a free plugin from renowned company Voxengo.

They have a M/S plugin for AU, VST Mac and Windows. It’s free. It has a lot of utilities built in to split the signal, encode, decode, or do inline editing of M/S signals. You are then free to route your stuff as you want I guess. Or split the signal first into 2 channels, not processed, just plain copy of the signal. Insert MSED on both channels and use the gain knob in one channel to mute the side signal, and mute the mid signal in the other. It’s really powerful.


Thanks for the link, Chris–I’d heard of Voxengo and some other solutions, but figured it must be possible to set something like this up using internal routing alone. It probably is, and maybe someone’ll chime in, but until then, I suppose I can rock the MSED.

I’m sure you can set it up the manual way without plugins. But why walk 100 miles on foot when you can take the car. Even if it would be possible :wink: