Christof,
> 22ft wide and 48 ft long <
Wow, that's really big. The good news is a large room has fewer problems with bass than a small room. The bad news is you have so much volume that you'll need a lot more bass traps and other treatment to tame it.
> One side (length) will be sheetrock the othe wall (length) will be exposed brick. <
I don't see a big problem with slightly dissimilar surfaces on the side walls. It would be more of an issue if one side were highly reflective and the other side was open or much less reflective. Once you treat the first reflection points on both sides with absorption, that alone will make the two walls "acoustically equal" where it matters.
--Ethan