well, today is my first day trying to get the M80's properly settled into my new apartment. But the bass response is thin. I need some suggestions!

here is the current situation:

the room is 18 by 12, about 11 feet ceilings
the m80's on a 12 foot wall
they are 1 foot from the side wall, 1 foot from the back wall
they are 10 feet apart
i sit about 10 feet back
bass seems weak in most spots in the room except in the rear corners

any ideas? PLEASE?!