I suspect that this is a myth created by the plugin industry mainly (brainworx being one of the most notorious in promoting mid/side stuff over the years).jBam wrote: Fri Feb 04, 2022 9:46 pm M/S has its place. The fact that it can destroy panning makes me confused why people relate it to / use it in mastering so often.
Mid/Side processing, at least of all the people I know in my local little audio mastering business here in Finland, is mainly one of those "last resorts" type of deal.. or used _extremely subtly_ for tiny enhancements. You only use it if you absolutely need it. If there are things that are out of phase elements that are vastly too loud, then you'd use EQ on (or compression if it's dynamic in nature and that happens to fit better the overall mix) it to tone it down and make it more balanced.
The problem with any kind of mid/side processing, even if it is super subtle, is that it very easily "detaches" the core, aka the mid where all the energy is, from the side which can cause some serious cohesion breaking. Things that are hard panned yet very tight together can break up and not feel "attached" any more.
So yeah, I have no idea why it is always touted as the be-all/end-all mastering solution. It most definitely is not! At least not in my experience.
.. but for mixing and sound design it can be and often is very useful! I almost always use EQ on the sides of my reverb and delay sends, to precisely carve out what parts I want to be mostly centered. For instance on a snare reverb send, you can force the brighter parts of the reverb to be almost mono, to give the snare that crack in the center.. whereas the low end parts can be more at the side, giving the illusion of a snare that is both centered but yet not ordinary mono.

