Here's a good "make your own bass traps and HF damping panels" link.

http://www.ethanwiner.com/basstrap.html

If you're up to trying different components I still think you would really like M50s, with the caveat that I have heard neither 22s or 50s.

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8