Modernists Unite, or: saying no to room treatment

No question that the room itself makes a difference. I've just moved from a single home where I had my system on the 2nd landing that had wood floors. My turntable was sensitive to footfalls and when the system was cranked I experienced audible bass 'boom' in the room (late at night I more than once thought someone else was in the house dur to this crazy noise!). I've since moved to an apt. complex built 20 yrs ago, 1st flr, smaller room, carpeted but concrete floors, walls, and ceilings. I can jump and down in front of the TT without it mistracking now, and there's no doubt, my system sounds better in this room. Of course the biggest drawback is I'm a big believer in apt. etiquette, so I don't do any late-night blasting but....As far as room treatments, besides carpets, drapes, bookcases, etc. I don't use any but not because I don't believe they'd work, just never got around to it or had the desire to spend what can be big piles of cash to do it right!