Hello all - we just built a house with an upstairs closed off bonus room (this is the only upstairs room). It is a large 850 sq ft room approx 33x25'. It has 9' ceilings with 2 rectangular raised trays to 10'. I lost the battle with the wife to divide this room into 2 rooms and get my dedicated Theater. So it will be a multi-function room. On one side will possibly be a pool table, kids area, on the other side will be my "theater". I haven't bought the equipment yet, but I have it wired to the max by the builder (Liberty cable in the ceiling, 7.1, headphone and RGB wall inputs, dual subs, and home runs going to a walk in closet across the room. My biggest challenge is what to do to contain the sound. The kids rooms are directly below this room. There is an insulated floor system seperating them, but I know better than to think that will do much. This is the only room that I havent done any flooring in yet (just OSB for flooring). Should I do a layer of plywood & Green Glue on top of the OSB upstairs, should I Quietrock the kids rooms below (cant get a call back from the Quietrock dealers in this area). There will be carpeting down as soon as I can figure out what to do here - and I need to decide fast. Any help would be greatly appreciated. Thanks!

Anybody? Help please! :)

There is a lot of info in this forum about sound management within a room and not much about sound proofing or isolating a room. If you search the internet you should find sites that have info for and by those constructin home studios and control rooms who have sound control concerns. The are some good vendor sites. STC (sound transmission class) ratings will become meaningful- who wud a thunk it?

I have no opinion about green glue, but from my own reading you need to look for ways to reduce transmission-- lows are very tough. Two layer surfaces separated by flexible strips for example are often suggested for walls. Adding both dampening and mass are often suggested.

You will need to treat walls and floors and openings. Solid core doors work well. Carpet and kind of pad are important.

Do not confuse reducing sound transmission with acoustic room treatment, such a bass trapping. The last may give a better sounding room but it will not reduce the sound going to the room below.

You might want to start with Wikipedia http://en.wikipedia.org/wiki/Sound_transmission_class or this http://www.cwc.ca/design/building_science/sound_control/index.php

You're still going to have some bass transmission simply because the structure is shared and not isolated.

The best idea IMO is to pull up the OSB that's down, put in some stud isolators, and float another floor up a few inches. Fill the space with insulation. Do the double flooring on top with GG and use 2nd layer of 5/8 drywall downstairs on the kids' ceilings with GG. This will provide better but not perfect isolation between the spaces.

If the significant other wins again and this is not feasible, I'd still definitely do the double layer thing on both sides with GG.

Bryan