I'm building a house and a theater room. I don't really care too much about sound proofing from the theater room to other rooms within the house, but I don't want to have such little sound proofing that the neighbors can hear my theater.

the room will be about 100-150' from the neighbors and 75' from the road about. I did some calculations and it looks like the sound should drop about 33db's in 75' and 39db's in 150'. Now figuring the loudest noise from the theater would be at most 120 dbs listenting at reference levels, that means with 0 stc walls the Neighbors would hear 80-90db sound or so.

Also figuring that the 120db noise is likely to come from the subwoofer in general, most db reduction seems to be pretty poor in the 20-80hz range.

From what I can tell normal construction walls with blown in insulation is roughly 40stc generally, but at 80hz and below 20-25 stc is more realistic it looks like.
The outside of my house will be brick which looks to be maybe 10stc or so by itself, I don't know how exactly this figures in though I doubt it simply adds, anyhow I figure with the default construction my outer wall is probably going to be about 30stc in the 80hz and below range.

So that means that the neighbor standing outside his house will be able to hear 50-60db noise from the subwoofer on big explosions, which seems still kind of loud.

So does my math/figuring look about correct, and if so what do you think you would do to keep the neighbors from being bothered?

Thanks!

either green glue and/or room-within-a-room or staggered studs would help with bass issues. RWAR is the most effective if I remember correctly.

Been looking at both, is this usually necessary just to keep the sound away from neighbors?

Sound isolation is the way to go if you think your next door might attest to that.

If your theater wall is going to be an exterior wall, I would double wall it with air space in between or a simple staggered method would be better than standard studding. Double dry wall on both sides as well.

I have been outside of Art's place during a demo session, which is pretty impactful. Art's room is a DE design, so it was built right (although pre GG, I believe). He also has some serious equipment in there, including his recent audio upgrades. While this stuff is audible, and shakes the siding on his house - I am not sure how much it would bother a neighbor, even if their place was closer.

I guess what I am saying is with a bit of effort you should be okay. Or PM Art and ask him how loud it was outside of his house with his old, non-DE designed theater that was in the same spot in his house.

He and his family throw a great party too, BTW.

Thanks, thinking about it some more I think my biggest weak point is probably the 1 wall that's an outside wall, the room is at the front center of the house so I bet laterally the sound won't be too much of a problem, since it'll have to pass through 3 or so walls and a few rooms.

The outside wall is particularly bad too because it has a 5'x6' window in it, which from what I can tell reduces the STC value fairly significantly usually. I read somewhere (either STCvalues or greenglue's website) that people sometimes create some kind of window plug that is openable, although I've yet to find any product like this yet.

Anyone seen a window plug before? Preferably one I can open and close?