I've been playing around with Mid/Side processing in Eurorack, lately. As it's not easy to find helpful information on that topic, I thought it might be a good idea, to start a thread here, for discussing and collecting information.
Mid/Side processing is a commonly used mastering technique (more info here and here), but can also be used in modular synthesizers, to enrich/enhance/manipulate your stereo image. The basic principle is based on splitting a stereo signal into one sum (Mid) and one diff (Side) signal. These are mono signals of their own, which can be processed independently and differently, before being combined, to form a stereo signal again.
In Eurorack this can be done with modules such as the Worng LRMSMSLR or Shakmat SumDif.
I usually use this method inside my system to gain a wider stereo image, by splitting my master stereo out and processing the Side signal as follows: cutting its low end, boosting its mid frequencies and raising its volume. Works pretty well (apart from that irritating but logical behaviour described and clarified here).
I think it's a great technique to play around and get creative with. I would be interest in how others judge and use this in modular synthesis. What are your experiences, tips or best practices regarding Mid/Side processing in Modular?