What is the correct way to use multi band compression in a studio setting?

Question

I use compressors quite often and I am quite familiar with their use to control dynamics but I haven't really got a good enough grasp of multi band compression.

From what I understand, the equivalent would be to put your signal through a number of parallel BPFs crossing over at adjacent frequencies, compress their outputs separately and then mix/add them back together. Please correct me if I'm wrong.

But as you apply a different amount of make-up gain on each band, doesn't this affect the tonal balance of your signal? Is this something you use them for? Or is it a side-effect that you should compensate for?

How do you decide where to place your crossover points?

Answer 1

I'd say that second paragraph is pretty accurate.

"doesn't this affect the tonal balance of your signal?" Yes

"Is this something you use them for?" And yes. Basically, a MBC is giving you frequency specific compression, allowing you to make a track stand out more, while leaving a greater dynamic range than with normal compression.

"How do you decide where to place your crossover points?" This is something I always have trouble with. I've seen people use them as de-essors (and de-essors ARE basically specialized MBCs). I've seen people use them to get a more sub-bass sound out of an actual bass guitar (to avoid bringing in the fret and finger-sounds). The purpose of using the MBC defines where the crossover points will go. Here's a good guide though: https://ask.audio/articles/mixing-tips-understanding-multiband-compression

Lastly, a warning. MBCs are finicky and can ruin your mix very easily. Start very slowly, and keep notes of what sounds good, so you can go back if you go too far.