One-way,
Upgradeitis issues aside
, you will be able to hit very loud SPL's with the M22's. I have a room slightly larger than yours and have the W22's. My system can go louder than I am comfortable listening to for any extended period of time. Without pushing things I have easily measured 100dB - I am sure I have been louder but without the SPL meter in hand. In short, buy the system that suits your interests and budget best, but don't be worried about lack of SPL from 22's in that size of room with a good sub.
