Trying to build a near ref. listening room? Help

I am trying to build a near ref. listening room in my new construction basement. I need the most help isolating the ceiling. I am planning on using double wall construction for the interior walls. Dimensions are appx. 14.8'x22'x9'. Also planning on running the heat vent into a side wall inbetween the concrete blocks so not to compromise the ceiling or interior wall integrity. Regarding lighting, will wall sconces hurt. What about electrical outlets? Your help is greatly appreciated. Tim
Re ceiling - I don't know about the asthetics of it but acoustically i think its worthwhile to use exposed beams to reduce early reflections just as you would use carpet to damp early reflections from the floor. Dimensions "sound" good. Wall scounces should have no negative effect just keep your electronics on a dedicated line apart from all out electrical outlets, wall sockets or lighting.
If its double wall, then you have the option of making the walls non-parallel, which will help. A TACT RCS 2.2x might be a cheaper solution!
Not sure if this would work, but if your room is going to be a "room within a room" in the basement, if you could somehow build a small door into the wall behind where the rack is going to be, it would make changing cables sooooo much easier....
Keep the room parallel. If you do have a problem later there will be a predictable fix. I can attest that having angles at the ceiling wall junctions will greatly improve your sonics. I have found by accident that a lot of accoustic energy likes to stick on 90 degree angles and rear its ugly sound later. You are welcome to e-mail me for the degree of angle to be used. Based on your dimensions and volume. Tom
My wall sconces rattle at loud volumes. I had to silicone the glass diffusors to the metal parts of the fixtures to *minimize* rattle, but they still make their own noises.
Your room almost has perfect dimensions according to the Golden Ratio developed by Fibonacci. This is a series of numbers which avoids resonance problems in the room. The ratio is 1:1.618. If the dimensions of your room start with 9 feet, then the others should follow this progression. 9x1.618= 14.56. 14.56x1.618= 23.56. Therefore, with a 9 foot ceiling, your room dimensions should be 14.56 feet by 23.56 feet. This also works for speaker position. Multiply the room width by .276 to get the distance from the speaker front to the near side wall. Multiply the room width by .447 to get the distance of the speaker to the back wall. This will give you a progressive ratio of 1:1.618. With a room width of 14.56 feet, the distance from your speaker to the side wall should be 4.02 feet. The distance from your speaker to the back wall should be 6.51 feet. The distance between the two speakers should also be 6.51 feet. To provide a proper 60 degree angle between the sweet spot and the speakers, the distance between you and each speaker should also be 6.51 feet. Using these distances will allow you to hear perfect sound imaging.
If you truely want a reference sound room, you can construct your room with the Iso Wall System from Acoustical Science Corporation or ASC. This system uses resonant sound channels, Wall Damp pads and strips which convert vibrations in the wall or ceiling into heat. This will eliminate the boom bass sound in the walls. Check out their website at This is enough for starters. Good luck with your sound room!
You might also solicit professional advice. Rives, an A'gon member, specialises on the subject and he's an audiophile.
BTW, GREAT project, you lucky devil :)!
Greg, thank you. Please do visit our site. I'll be very frank here--designing a reference listening room is not easy, and it's too expensive to do it wrong. There is so much that goes into it, from sound isolation, dimensions, construction methods (why 2 layer vs 1 or 3 layer), parallel walls vs taperred walls, aesthetics, expansion of the sweet spot and limiting bass mode build up in particular areas of the room. While, of course I'm very biased here with my next statement, I do strongly believe our design costs compared to the sonic benefit achieved is possibly the best value in high end audio. Here are some links that might prove useful to you:
Art Ludwig's site This site has some very good resources, somewhat technical at times, but very good information.
John Risch's site This site is for DIY treatments that can be applied to a room after the fact. This is probably less useful to you, as it doesn't really go into what you need and where, and since you are building the room from scratch I wouldn't really recommend using devices such as this, because optimized devices can be built into the room--rather than placed in the room later. It's very good for the DIY person that has an existing room, or if you plan to move and want to take acoustic treatment with you--then this may be a valid option.
Rives Audio "the Listening Room" This is our basic tutorial on room acoustics issues.
Rives Audio Consulting Services page This is where you will find the different services that we offer.
There are also some very good books on the subject. Alton Everest has a few: Master Handbook of Acoustics, and Studio on a Budget. Both very good and available from Amazon. Hope that helps.
I have a few different Pass & Seymour and Hubbell duplexes when you need somem, as well some advice about dedicated lines. RSVP when you're ready. Cheers.