Axiom Home Page Forums General Discussion Home Theater Sound proofing question...

I am sure you guys know a thing or 2 about sound proofing but I really need some advise here.

I already put up the walls and painted them in my theatre room in the basement. I was planning on a drop ceiling which is why I already painted and such.

I have been researching and have found out that It would be more benefitial financially to just use Quietrock drywall on the roof with some high density fiberglass insulation above in the joists than to install acoustic ceiling pannels that have a decent STC rating (the best STC rating i could find for ceiling pannels were 27 whereas the lowest quietrock product has 52-70 STC).

My dillema is this; 3 of the 4 walls are backing onto the concrete foundation, so there is no sound transfer there. The 4th wall backs onto the opposite side stairs going upstairs which I failed to insulate and do any sort of sound proofing on.

Will it be benefitial to spend a little more money using quietrock drywall on the ceiling (5/8") at $50/sheet (i'll probably need 7 sheets for the ceiling) even though sound will still transfer through the wall backing onto the stairs upstairs? Or should I just use regular drywall on the ceiling because if one of the walls will transfer sound out then its kind of a weak link?

Some of you guys with dedicated rooms please chime in.

I still have access to the part of the wall backing onto the stairs and will stuff all kinds of fiberglass in there to prevent further transfer of sound.

-Hutz

I just had my basement redone and built a new HT room. Basically, the contractor installed R-19 installation within the new four walls. He then added high density fiberglass (Johns Manville, I believe) in the ceiling joists. I am pretty happy with the result - only low bass escapes through the ceiling, which was expected. My drop ceiling is lined with regular ceiling tiles.

I would definately put as much fiberglass in the back wall as possible. From talking with experts, leaving just one wall untreated negates the effect on the other treated walls. Since you cannot cover the entire wall, I would not spend the extra money on the QR drywall because sound can still escape through the untreated parts of the back wall. My contractor also recommended ceiling tiles over drywall ceilings if your waterpipes run through the basement ceiling.

Not much will stop Lowwwwww bass from being heard. Just think about it, when a dump truck or garbage truck drives down your street, you hear them coming for blocks.

I will be able to access part of the exposed wall from under the stairs and stuff some fiberglass in there, but part of the wall I will not simply because it is being used as a cold air return from the ceiling being routed through the wall. I wouldn't want to have fiberglass particles being sucked into the furnace!!

lol, my wife is going to kill me, earlier today i just told her that Drywall is going to be the choice for the roof, now I am back to ceiling tiles...geeeeze!

I was planning on using fiberglass in the joists above for sound isolation. If you find it acceptable i am sure It will be ok. I am just thinking it won't make much difference than what i have now (bare joists) but it probably will make a big difference.

I do as much as I can to insulate those areas with fiberglass...

-Robb.

703 and other similar products are used for sound absorbtion, not as sound barriers. It would cost to much to use such materials within your rafters. I just got some thick regular insulation with the paper on one side to stuff in my rafters before adding drywall. Still, the EP500 can be heard by my neighbors.