Right now, the bottom of the joists have 1" fiberboard over the entire ceiling. It's heavy stuff, not sure exactly- got it second-hand from an acoustic designer near here, but it's about twice the weight of the 703 I got for my bass traps. Between the joists I stuffed 6" fiberglass blankets, and before I did all this I caulked all the joist edges to the 3/4" OSB floor deck above. So my ceiling is a great bass trap (according to theory), but it's not providing much separation besides the floor deck itself.
But its part of a sound leak, because once LF sound gets into the ceiling area, it goes over the wall diving the studio from the rest of the basement. And from there it goes wherever it wants. So I need to plug the space over that wall, between the joists. Not too big of a deal, really- the joists bear on this wall, and they butt up against each other there, so there's a solid end-plate for each one meeting up right there. I figure I can screw a 2x2 into each side of the joist and set a small plywood rectangle in between each space to plug the leak. There's a heating duct and some plumbing thru one of them, which will be a pain, but it's doable.
I'm just thinking about the joists themselves. The ends are basically a 3.5" 16ga steel stud set on end, and having 2 of them pressed together doesn't make me feel much better. It'd be possible to set a short section of 2x4 into the steel stud, but it'd be a pain in the ass.
My only other option to really fix this would be to drywall or osb the whole ceiling. I do NOT like that idea, and not just for the cost- all the LF absorption I'm getting would vanish, and since my room is basically square I need all I can get.
What do you guys think?
Most of the time I'm talking about the studio I plan to build in the future... the existing room is an exercise in doing what I can with what I have, so don't laugh too hard.
Sorry if I spent a lot of typing on a small problem... it's tough to describe without a picture...Thanks!
Kase
www.minemusic.net