How to create an M/S processor for a stereo Aux. Rtn?

[mahler007]

Hi,
In ProTools, is it possible to take a stereo aux. return and route it- via a couple of internal busses- to a homemade M/S processor before going OTB?

I'm almost certain that it is, but I'm having trouble figuring out how exactly to do it. Yes, I know the whole M+S=L and M-S=R formula, but I'm not exactly sure how to implement that in the real world.

Anyway, if anyone could show me a path, I'd be grateful. I'm working on it, and have some nice sounding results- I may even have it right, but i'd like to know the text book way if at all possible...

Cheers,
Andrew

[guitardom]

i stole this from a website a while back, i wish i could say who it came from. works great and hope this helps


Encoding


Take the stereo source track and output to bus 1 and 2. Create 2 stereo aux tracks (M and S)
. In each aux track set the input to both bus 1 and 2, and insert a plug-in that is capable
of reversing one of the channels. I use the time adjuster plug-in for this, but any EQ or
compressor plugin that supports a polarity change will also work fine. Be sure to insert
the same plug-in in both tracks or the latency between the plug-ins might be different
which may cause a phasing problem. For the M stereo track leave both sides of the plug-in
in phase and output to bus 3. For the S channel reverse the right channel of the plug-in
and output to bus 4. Also reduce the level of both M and S faders by 6 dB to avoid clipping
and to provide the reduction needed so that the output is not doubled.



Decoding


Again create 2 stereo aux tracks, set the inputs for both to bus 3 and 4.
The first one we will use as L and the second as R.
On the L channel keep both side in phase,
on the right channel reverse the phase of the right side of the plug-in.
The outputs from these channels can then go directly to another stereo aux track
(set inputs on bus 5/6) for further processing,
or you can send the output directly to an interface by hard panning the L track left,
and R track right.

Once all of this is setup, try reducing the M and S channels to hear the effect.
Reducing M should make the stereo field sound "wider",
increasing it more "monophonic".
Next try inserting various plug-ins in both the M and S channels.
You can bypass the plug-in in the channel where you are not going to use the effect for,
it's just there to ensure that the latency is the same between both channels.
Listen to the effect of EQing or compressing the mid channel versus the S channel.
You can also try using other plug-ins rather than the normal EQ or compressor and
automating the M or S channels (handy for specific issues in a mix,
like de-essing the lead vocal on the chorus of the song).

[mahler007]

dude- this is awesome!
Thank you!!

Cheers,
Andrew