Originally Posted by Dennis Erskine
There are several varieties of Quiet Rock. The QR545 is higher performance level and is rather pricey...but effective. Your best bang for the buck may be two layers of drywall with Green Glue between the layers. Green Glue (it's not an adhesive) is a viscoelastic damping agent. You can easily match, or exceed, the performance of some QR assemblies. www.soundproofingcompany.com
has some good information on their website.
You wil still require acoustic treatments in the room.
I have used the Quietrock product for my theater (23X21X10) The room has no overlapping nodes according to Room Sizer(TM). In addition, I have included enough opera curtain to level the RT60 from 100Hz to 8kHz to 110ms. The opera curtain is arranged within soffits between pillars and the room is completely sealed with Quietrock and the sealer recommended by the makers of Quiet products.
An important feature of QR is the sheet metal separated by viscoelastic layers. Once this is sealed, it becomes airtight. This is very good for restricting air as well as sound so have your air handling in mind.
For air handling, I have used (with great sucess) long lines of pliable ducting covered in rockwool. If arranged in a serpentine fashion with lengths of more than 16' for both the supply and return ducts, you will get good performance for low bucks. For your door, just make sure that it is very heavy (nothing can replace mass) and use a high price weather stripping product...you'll be suprised at how well this works.
If you go through all this trouble, it's a good idea to build a projector housing with proper glass and a heat exchanger. It would be a pity to spend the money on the isolation environment only to listen to the projector fan during quiet parts of the movie.
Make sure your treatment is also optically diffuse and very dark...this way you'll be able to knock peoples eyes out with a high gain screen and as little as 1100 lumens (I use a 122" diagonal FireHawk screen w/a Runco CL-710. The projector height is selected to allow for downward tilting of the screen to reduce residual standing waves and keystone correction.
Beyond that, I balance the line level distrubution to the Blue Sky 10.2 Powered System
(2200 WRMS). This allows me to run any format (AC-3, DTS, EX, ES, 7.1, SDDS and Neural).
My choice of Blue Sky is a result of a positive working experience with them at Skywalker Ranch (LucasFilm). I've never regretted it (two years of abuse later).
An Integra DTC 9.8 supplies all of the brains along with very robust balanced line outs ground floated at the destination.
Audio and video AC come from home runs to the main breaker box (very low impedance)
The room is quiet enough that I can hear the noise from the loudspeakers at 6' with 102,000 BTU's of AC compressors operating on the other side of the wall.
This stuff really works, but you have to install it correctly. It is heavy and requires a diamond saw to cut it (because of the metal layer), but the results are far superior to multilayered sheetrock.
Oh, and BTW, leather seats look nice, but they absorb bass and reflect highs. Microfiber covered seats give more consistent results (sabines/F). But then, if you have a tubby room maybe leather is better, YMMV.
I'm no expert. This is merely my experience.
rob r. (still talking too much