HT Wall and Ceiling Insulation Question


Jun 9, 2003
I have my HT framed and have been doing alot of research regarding sound proofing/sound insulating the room and have come to the conclusion that I am more confused now then when I started. So I am seeking advice.

My HT is in my basement (below my master bedroom) and the dimensions are 38' long by 16' wide with 9.6' long with one back wall on a 40 degree angle - so it is not rectangular. I have wood framed walls and have put rubber or foam insulation separation where ever I could during construction. I plan to use heavy roofing tar-paper over the insulation and framing, covered by 1/2" drywall and then carpeted walls.

So the question comes to what to use for wall and ceiling insulation. R13 insulation, soy foam, pink foam board, combination or something else? I'm not sure if there is any true benefit to using the soy, other then someone other then I will be doing the insulation.

Does anyone have any opinion, experience or advice regarding the selection and best way to insulate/sound insulate the HT?

Thanks in advance


Second Unit
May 27, 2002
Everything I have read on the issue of sound isolation / soundproofing has repeatedly stated that the best bang for the buckis to use the typical fiberglass insulation rolls, or "batts" which one can purchase readily at a Home Depot or a Lowes. I have also read (repeatedly) that blown in insulation is basically useless when it comes to stopping sound from traveling.

There are a few exotic exceptions to this general rule, but most of them are so exotic that they are not even tough of as insulation. For example, installing the heavy, heavy rubberized soundproofing products (which are expensive and incredibly tough to install, resulting in lots of labor costs).

Other than the above, the usual R-13 or R-19 batts are apparently as effective as anything, according to all of the testing reports.

There ARE a lot of other factors that can improve the soundproofing, if the drywall is not yet up. I will try to summarize...

-Decoupling, or partial decoupling. There are products that you can use when installing drywall (for example), which will effectively isolate the drywall from the studs, so that little vibration picked up by the drywall is transferred into the framing members of the entire house. One of the best is known as RSIC clips. Do a Google search.

-Doubling up on drywall can make a difference. Increasing the overall mass of drywall can make a difference. So, 5/8" drywall is better than 1/2". And, two layers of 5/8" drywall is much better than only one layer.

-There are products devoted to "damping" the sound. I used one of the best, according to a lot of testing. It is called "Green Glue." This comes in tubes that you pop into a large regular caulking gun, and then you spread it so that it is "sandwiched" between two layers of drywall. It is reported to be very effective. It costs, of course. But, it works, and the company has paid for tons of extensive testing to demonstrate this again and again. Do a Google search, if interested.

-Paying attention to openings. This is important. You could spend $10,000 in exotic soundproofing product, but then see it all go to waste because you forgot about that lousy door which is hollow core, and has terrible openings around the door itself which allows all sound to travel right through it. I caulked. I paid a bit extra for a solid core door. In fact, I installed an exterior door, to get the rubber gaskets, the threshold, etc. Then, I caulked around it. I caulked around my electric outlets, switches, sconce boxes, etc. One of the best experts uses this metaphor, for the room:
-Think of the room as an aquarium. Now, think about those walls, and also the bottom. You could spend thousands on the very best, thick, solid glass with tons of mass, able to withstand tons of pressure... but that two inch hole you forgot about in one side means all of the water can still drain right out, and quickly. The Home Theater is like an aquarium. That overlooked something (perhaps a heating duct which allows sound to travel right up to your bedroom) might negate all of your dollars invested.



Sep 2, 2006
Real Name
Re: Soundproofing.

Any opinions of the sound-dampening wall boards that have standard dimensions but claim the attenuation of up to 6 layers of regular board.

Also I thought that facing just the studs and beams with some kind of rubber or similar membrane prior to installing the walls would reduce another few Db.

My project is very small in layout, and I'm trying to find $ and labor-saving best bang for the buck strategies.


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