Please Help

[Denm]

I’m in the design/research/buying phase of building my dream home theater system. Like us all, I have a million questions, and don’t want to make any crucial mistakes. In researching, I have found the Audioholic website to be a very useful resource, and would like to utilize the sites knowledge throughout my build.

My main concern at this time is to have a plan for the overall acoustic treatment of the room. The room is actually a 15’x 8’x 40’ (I’m framing the back wall at about 28’) bonus room above my garage. This is nice, because it is somewhat isolated from the rest of the house. Even though isolated, I am thinking of using MLV on the floor as well as the back wall to even further decrease sound transmission. As you can see in the pictures, the room is not even sheet rocked yet. Do I need to sheet rock the room, or would I be better off leaving the sheet rock off? I have been messing around with building panels from duct board and covering them with colored burlap. It seems like it would be counterproductive to cover up the insulation, and then try to tame the room again. Notice that behind the side walls is a large cavity. If the side walls were left as is, and covered for appearance, would it act as a huge bass trap? Do I want the room as dead as possible?

All comments are greatly appreciated.



Equipment List:

HTPC: Custom Built (Similar to that from DIY on audioholics.com)
Projector: Panasonic AE700U
Receiver: Integra 9.1
Center Channel: 1) RBH SI-6100
Surrounds: 6) RBH SI-760’s
Subs: 2) RBH 1010-SEN’s
Sub power: 2) RBH SA 400’s www.rbhsound.com

 

[zumbo]

I am NOT qualified to give an answer. I do have an idea. Why not use MDF (medium density fiberboard) on the walls. If it can hold the sound inside a speaker cabinet, just think what it would do for keeping the sound in the room!

 

[Denm]

I guess my biggest problem is knowing how much absorption material the room needs. I was reading Patrick Harts’ article on room acoustics. If I understood correctly he recommends only 25% coverage of absorption materials. Does this sound correct, I was thinking around 75% absorption and 25% dispersive? I know I want to take advantage of the cavity behind the walls(shown in picture). I’m thinking of constructing sound traps of different depths and placing them so they enter the open cavity. I can construct these panels out of MDF and fiberglass insulation, attach them to the walls flush with the front of the studs, and cover them with something attractive. I’m not sure what proportion of high medium and low frequency traps I need. Also when constructing traps (not caring about depth) would it be better to use regular fiberglass insulation rather than semi-rigid? How thick should they be for different frequency absorption? I’m also planning on using cast stone veneer for the diffusion surfaces. See www.harristone.com

 

[mirage1]

I'm in the learning process myself but here are a couple of site that you should read & you can always e-mail Ethan for more help. Acoustic treatments the most important part of your room There is also modeling software to help also if you do a search for Cara not sure how good it is but alot of folks rave about & not very $$$ Hope this helps

http://www.ethanwiner.com/acoustics.html
http://www.realtraps.com/
http://www.rivesaudio.com/home/home.html
http://www.geocities.com/jonrisch/a.htm