Need Help Designing a Dream Room

Actually, I WOULD NOT recommend you using 3 layers of sheetrock INSIDE the actual listening room, as the other gentleman suggested!!! you do't want the walls that unforgiving and stiff ideally! if you do put 3 layers, or the likes, you should do it on the OUTSIDE of the room, allowing for the room to have some give (instead of soundig hard and unyielding!), and let bass be naturally absorbed better, and simultaneously keeping sound out/in, etc.!!!
Anyway, i'm sure there's some good ideas that were mentioned here. And, as a custom home theater/room designer/acoustical engineer myself by trade, may I suggest you either get a professional to do the actual design work of the room (too easy to make big mistakes if your serious about your endevor, and a novice at the same time!?), or do lot's and lot's of home work!!!
Still it's hard to attack all the variables, if you don't have experience in to what does what, when you do this and that! Some things help, others make worse!...and so on.
There's no substitute for experience in this case (as many), and you'd do well to get some assistance from someone with the right expertise (my advice anyway)!
Actually, if you did want to get into it the correct way yourself, and wanted to do your own design work on this project, you should try to attend "Russ Hershelman's" work shop in San Francisco next month!!! I think there's still seats available, but the price is $750 (well worth it for what you're going to get, and what your investing in!!!). If you don't know who Russ Hershelman is, he's non other than the top Custom theater/room designer/engineer/ in the world!!!! He designs and egineers for all the biggest clients, and works with the biggest custom theater installers in the biz! Anything to do with designing sound rooms, and he's probably the man to listen to!!! He also runs articles in 3 top magazines (Home Theater, Stereophile's Guide to HT, and AV Interiors I belive (?). He's on going articles in most I think, and his knowledge in these area's is second to none!!(although I like to think I'm close to his league!!!...?). Anyway, best wishes on your endevor! Audioalexander....

I do not know the gentleman who you so deeply respect that does home theatre. The person who believes that multiple layers of sheet rock are not good.

My advice is not from my own experience, but rather from Russ Burger, the studio designer. Russ did Whitney Houston's studio, the acoustic work for Woody Allen and the new CBS recording studio. He is currently working on NFL studios, and in the short breaks between, has been kind enough to advise me on my room acoustics.

You are welcome to dismiss my opinions on audio, but as for acoustics, I prefer the advice of the guy that is responsible for music rather than theater.

Ozfly,

I won't comment on Albertporter's or AVDcreations' recommendations on what to do. From previous posts, Albertproter has a room envied by many AudiogoNers, past and present.

However, both Sean and Albertporter have good thoughts on HOW. It is way cheaper to do things now than to put in something that is only half of what you want with the plan to "make it right" later. Besides, you never will. Most of the construction improvements will cost hardly more than the material upgrades if planned for now. Things like 1-1/2" thick subflooring or conduits run through the slab will be prohibitively expensive or impossible if not done now.

Also, please listen to Albertporter when he suggests that you carefully supervise the plans. Supervise the construction closely, also. There will be plenty of places for a contractor to cut corners with the unusual specifications that a sound room like this wil have. From the new construction I've seen recently, contractors cut corners on normal stuff already. For example, if your final design calls for laminating three layers of sheet rock on all the walls, you'll have to make sure that the contractor uses glue between the layers. If he's not watched, chances are he won't.

I hope I haven't offended any members who are contractors. This has been my previous experience.

Sean, Kelly, Albert -- thank you very much for your responses. You are most kind in taking the time to lay out your thoughts. Alexander (I assume), thank you for your comments as well and for reaffirming the suggestions that I seek professional help -- my wife has recommended that for years, but that's another story;-) I have heard that you don't want too much reflection or uneven (frequency wise) absorption but don't know enough about the properties of drywall to comment. A friend of mine once built a small sound studio surrounded by sand bags, but my wife would frown on that. Albert is correct that my only purpose is for stereo as my more modest surround sound system is in another room. I'll check out the options for home acoustics experts, but please keep the suggestions coming. Thanks.

There are no absolute rules in acoustic design. You can ask five different acoustic engineers the same question and get five different answers. On the surface this may appear confusing, but if you dig deeper, you'll find that each engineer has a design philosophy. Each element of the room and the reproduction equipment are designed to synergistically interact in in accordance with that design philosophy. You can get into trouble if you mix and match individual design elements from different engineers. If you decide to get professional acoustic engineering help, you will need to determine the engineers philosophy and make sure it's compatible with your goals.

The issue of surface rigidity is complex. In general, for home music reproduction rigid, but not overy rigid construction is best. Some wall flexibility can lessen standing wave problems. This will give you flexibility if in the future you switch to a different speaker with different low frequency tuning. In pro studios hyper-rigid wall construction is preferred. In a studio every element of the system is optimized to work together. The engineer knows exactly what speaker will be used, where it will be positioned and where the listner will sit. It's optimized, but it's somewhat inflexible.