Like a few others here, I too am taking on a new basement related project and could use some good advice. In a nutshell, I already have a finished basement with my home theater setup, but some of that room is needed for a play area for my three daughters. My wife suggested we section off the basement into two areas: play area and a home theater area. Though the size of my HT may be getting smaller, I am excited about the possibility of creating a "better" room acousticly. My main concern right now is travel of sound through the ceiling tiles: my wife complains that she can hear the movie sounds through the floor of the family room, which is directly over the home theater area of the basement. Can anyone advise me on the best way to prevent the sound of traveling up through the floors? Most of the work will be done by a contractor, so don't worry about the complexity of the solution. Thanks for your help in advance!!

Hiya Royce,

Seems like smart people around here have already hashed this through a bit. I'm tempted to propose the old "sell the wife" solution.

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I insulated above all the drywall/walls and it did help with the highs/midrange, but the not sure if anything will help the sub lowsssssss, especially if your one of the EP500 or 600 owners

Mid and high freq. can be stopped with drywall and insulation, but bass travels through the contacting surfaces of the walls easily. The best way to stop it is to de-couple the inside walls and ceiling from the rest of the house. See this thread and many more on the subject of sound isolation at avsforum:

http://www.avsforum.com/avs-vb/showthread.php?t=567018

Instead of drywall on the ceiling, I used the 2' x 2' acoustic ceiling tiles, plus regular fiberglass insulation between the joists. Seems to work pretty well for me. If you really want to go all out though, here's a few links to check out...

http://www.quietsolution.com/quietwood.html
http://www.quietsolution.com/

A question about insulation: Would'nt installing insulation materials inside a drop ceiling be a fire hazard if you have those florescent lights in your ceiling? My basement ceinling also has quite a bit of waterpipes running through them, so I don't want an all drywall ceiling. I might look into some drywall ceiling tiling though.

dllewel,

Thanks for the link. I tried reading through it, but my head started to spin. I really need to learn what de-coupling means and maybe look into the Green Glue or RISC things that are recommended. I rate pretty low as a carpenter.

When insulating above and / or around light fixtures, make sure the fixture is rated for insulation. That’s a good point that was brought up earlier. The fixture has light gauge sheet metal shielding that keeps the insulation away from ‘hot spots’.

There is bat fiberglass insulation that is specifically designed for sound reduction. The difference between it and normal bat insulation is fiber density. When insulating for a thermal conductivity barrier, insulation needs to have “loft” where pockets of dead air space is captured between the fibers. A common mistake with installing insulation is to cram it in. You reduce its insulating properties when it is not allowed to expend to its rated dimensions.

There is also sound board that is installed on the joists after you install the bats between the joists. It’s downright obnoxious to install, especially overhead. It breaks apart and you are sure to get the fibers everywhere. It works very well though.

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A question about insulation: Would'nt installing insulation materials inside a drop ceiling be a fire hazard if you have those florescent lights in your ceiling?

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http://www.roxul.com/sw18169.asp

Wow, I wish I would have known about that stuff when I was finishing off my basement. Thanks for the link!

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Wow, I wish I would have known about that stuff when I was finishing off my basement. Thanks for the link!

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No problem. And the nice thing is that this stuff is not a heck of a lot more expensive than your typical pink insulation, yet it is so much more "robust". The people at Roxul are very helpful and are great at technical support as well.

As far as the noise insulation goes, the insulation is 3" and in a 3.5" space (typical 2x4 construction) you leave the air gap on the noisy side of the wall. Supposedly the larger the air gap (within reason) the better the sound transmission loss (less noise).

I am currently looking at 2x6 plates and 2x4 studs installed 16 inch on center on either side of 2x6. It is an economic form of building "two separate walls in one".

Speaking with one of my framing contractor friends, he mentioned that further isolation can be done by simply cutting slots into your 2x4s. This is done by using a table saw (or hand circular saw if you're good enough) to cut a slot that extends from about 6 inches from the end, leaving a 6-12 inch solid section in the middle and continue the cut to about 6 inches from the other end. I would imagine that the cut should be about 1/4" wide which is where a table saw would be easier. I think most blades cut at a 1/8" width. 1-1/4" drywall screws would then be used to fastent he drywall to the studs. This will ensure the screws will not penetrate past the slot and increase the areas of conduction. In this method, you can also get away with one layer of 5/8" drywall insteaad of two. Of two layers of drywall will drastically reduce the STC but it gets more expensive.

As you can tell this is for new construction and is very time consuming versus simply installing resilient channel. In addition it will likely not give as much isolation as RC. However, the real bonus is that it is no cost except for your time.

I would compare this method of construction to a product that is currently out: http://www.quietzoneframing.com/ However, I have priced this engineered wood product and while giving exceptional performance it is expensive. If I had the money, I'd have gone with this product but, alas, I have better places to spend my money (like paying off other debt ).

Bottom line, the better your room is built, the better the sound quality.

My friend's experience is that cutting the 2x4s works. I can not quote any data as to the STCs but it is definitely worth the trouble if you have a very strict budget. I know I am going to be doing this in my new Media Room.