Hello Jaime
From your post it sounds like the problem is not with the speakers but with the acoustic properties of your room. Here are a few sites which offer acoustic treatments for your room. You may want to check them out.

http://www.foambymail.com/Products.html
http://www.soundprooffoam.com/
http://www.auralex.com/main.asp

Good luck! Enjoy those beautiful M60s!

Enjoy the Music. Trust your ears. Laugh at Folks Who Claim to Know it All.