Hi All,
OK. So when I finished my basement I hadn't really planned on it becoming the dedicated theater that it has become. There's quite a bit that I'd hae done differently, mostly to improve in-room response. I have tried to fix some of those things by moving my sub around, installing some acoustical treatments, etc. (SMS-1 would be nice too. Maybe for my birthday.) But short of rebuilding the room to more appropriate dimensions, there's not a whole lot I can do there that I haven't already done.
I think the biggest oversight might be that I didn't use any sort of sound insulation in the floor joists above my drop ceiling. So when things are really going downstairs, you can really hear it upstairs. I was just wondering if putting some pink stuff up there might help absorb some of that sound. It's going to be quite an effort to pull all tiles to put the insulation up there so I want to make sure the rewards are worth the effort. Also, what products have people used in the past for this application? Any info you can provide is appreciated.


later,
simp

Batt insulation can act as a good acoustical dampener - architects use it often in internal partitions for just that reason. I'd probably go with a 6" batt (~R-19).

Thanks Gonk. Think I should hold out for insulation that is specifically designed as a sound barrier or will R-19 acheive similar results?


later,
simp

I haven't dug into it enough to have detailed info, but I suspect that it would be hard to noticeably top good ol' 6" batt.

Gonk,

Please tell me all you can about this. I want to use this above the drop celing to shield the sound. Where can i get this, how to apply it, etc?

Thanks in advance.

Basically there isn't much difference at all between acoustical batts, and thermal. At least not enough to notice the difference. In my old house I had 6" fiberglass above the fiberglass ceiling tiles. We had a party once with over 50 people at the house. There were only only about 10 people upstairs at one point, me being one of them. I could not tell there were over forty people and music below my feet. It was amazing!

I am currently building a new dedicated theater in my the basement of my new home and am doing the same thing. With just the insulation up between the floor trusses, it doesn't seem to make much of a difference. Unfortunately though I have several spots where the insulation has been removed to run electrical and plumbing lines. I hope to have the same results when complete.

The best way to insulate the sound in one room from the other though is two sets of joists. Let me explain:

I had this done in the walls of the laundry room in my new home. Place two sets of joists vertical on 16" centers, 8" apart from each other. Instead of 2x4's for the header and base use 2x6's. On one side of the wall bring one set of 2x4's to that edge of the 2x6 header/base and do the same on the other. This way when you screw/nail up the drywall each side of the wall is on a different set of 2x4's. Now there is no mechanical link for the sound to travel through. The only links are at the base and top, which are dead because they are atttached to the floor and ceiling. Then wind insulation through the 2x4's sideways to catch any extraneous sound.

Tim

I agree with Tim - we've used standard batt insulation in condo and apartment floors, where it exists solely for acoustical reasons (no thermal need for it between two conditioned spaces).

Your laundry room wall construction technique is a good one, Tim - much less costly than the "double wall" used to isolate fancy home theaters (one wall inside another), and it'd be nearly as effective.

Thanks so much. I will have to look into this.

This might sound kind of silly, but is your basement actively heated? The design of your house might count on there not being a thermal barrier between the basement and the rest of the house. Vapor barriers could especially cause some trouble. If your basement "breathes" up into the rest of the house and you clog that up, moisture could become a potential problem. That might be a significant functional difference between thermal and accoustical insulation. Not sure if it applies to your situation, but it's worth considering.

As a side note, my dad did s setup like yours, and used acoustical tile to help with sound. You could definitely hear the sub upstairs when the action got loud thoug. Highs and mids were pretty well subdued.