[Greg Bax]

What is a good room size for a HT? I am looking to build one as part of finishing the basement. Also should there be anything special on the room walls, like cloth or foam? (i.e. Movie Theater)

[Jack Briggs]

Well, Greg, that's a pretty open-ended question. Whether a room is a good size depends largely on the equipment you plan to use. Say you are in a small apartment. It wouldn't be wise, then, to cram a 65-inch RPTV and a sound system based on huge, floorstanding tower speakers in a 7.1-channel arrangement. Likewise, if you have a cathedral-style living room or dedicated home-theater room with a vaulted ceiling, you wouldn't base your HT on a 27-inch direct-view set and a small satellite/subwoofer combo.

What kind of equipment are we talking about here?

[Greg Bax]

The equipment is a Denon AVR-3803, Klipsch RF-35 for the front speakers, RC-35 for the center, RS-35 for the surrounds, and KSW 12 subwoofer. With a Sony WEGA KV-32XBR400 TV, but I would like to upgrade to a 60" Plasma in 2 to 3 years.

[scott>sau]

Three factors are discussed a lot with HT design and the room. 1)Room size, 2) Room shape, 3) Room acoustics.
You find the cubic feet of the room by multiplying LxWxH. You will be limited in height in a basement, but should be good for 1000, or more CF.

Rectangular room shapes are preferred. Dimensions should not be multiples of each other, (e.g. 8x16x20, 10x16x20, 8x14x28 are all bad).

www.acousticsfirst.com has helped me many times. They have a large supply of items to absorb, reflect, diffuse and block sound. A basement is great because it is dead. "The deader, the better".

(Credit to some of this info goes to Russ Herschelmann, one of CEDIA's founding fathers. Article: "Home Theater, Essential Elements", 1995, p.7).

[Drew Eckhardt]

At least 3' on each side beyond the left+right speakers (early reflections), at least 20' long (room for two rows and some feet between rear surrounds and listeners), and at least 9' high (room for a full-height ceiling on the second row) would all be nice. Using the golden ratio between dimensions (.618 : 1 : 1.618) is optimal.

Front wall should be covered in Theatershield, Insulshield, etc. along with the lower parts of all other walls. The top of the non-screen walls should be covered in batting. That in turn should be covered with dark acoustically transparent cloth (Gilford of Maine FR701 is the defacto standard). Flat black is best.

60" diagonal is way too small to produce a cinematic sense of immersion at domestic living room distances for even a single row of seating, and you'll need to be within 3-3.5 feet of a 32" 4:3 set for this to work out. The obvious solution here is two-piece projection setups, with the specifics depending on budget, space available (two-piece rear projection gives you ambient light rejection, but takes a lot of space and money), projector (some have visible artifacts that force sub-optimal seating locations, CRT light output forces smaller screens) and screen aspect ratio (the constant height/constant width/constant area debate).

Obviously, compromises are possible and which you make (sound treatment for 2-channel in a mixed audio/visual room or relying on DSP for ambience extraction, lighter room with theatrical drapes to kill reflected light instead of something all black, etc) are a matter of personal preference.

Hiring a consultant (Dennis Erksine, etc) might be a good idea.

[Bob McElfresh]

I'm going to move this thread over to the "Building a HT area" fourm.