Wooden Vs Carpeting for HT

Hey Venkat,

I am not sure if I can do this without the help of an expert hand. Anyways the information provided is real good. Thanks!

Sorry for some typos.

The sentence 'Take a plywood some 2 to 25. feet wide. The length should be 75& of your wall height' should read as

'Take a plywood some 2 to 2.5 feet wide. The length should be 75% of your wall height'

Cheers

If u use a plywood backing u will be introducing a reflective surface again.

I have made the BASS absorbers very cheaply with 2" x 4" wooden reefers cut to length, nailed to form a frame. the 2" thick fibreglass sheet is cut to size placed inside the frame. For the front I have used speaker grill cloth which is the best material for acoustic transmission and looks great too. The fibre glass sheet is held in place with nylon thread tied across crisscross fashion on the back. 4 3inch nails at the back corners provide 2" standoff from walls for increased performance.

see RealTraps - Acoustics Information for great DIY info.

giddavr - Page 1 - Photobucket - Video and Image Hosting will give you some idea. of what I have done.

gvr

HARD FLOOR, SOFT CEILING

The following is from an exchange that took place in the rec.audio.pro newsgroup in May, 2003:

Bill Ruys asked: Why it is recommended to have bare (un-carpeted) floors in the studio? One web site I visited mentioned that a bare floor was a prerequisite for the room design with diffusors and absorbers on the ceiling, but didn't say why. I'm trying to understand the principal, rather than following blindly.

Paul Stamler: Carpet typically absorbs high frequencies and some midrange, but does nothing for bass and lower midrange. Using carpet as an acoustic treatment, in most rooms, results in a room that is dull and boomy. Most of the time you need a thicker absorber such as 4-inch or, better, 6-inch fiberglass, or acoustic tile, and you can't walk around on either of those. Hence the general recommendation that you avoid carpet on the floor and use broadband absorbers elsewhere.

Lee Liebner: the human ear is accustomed to determining spatial references from reflections off of side walls and floor, and a low ceiling would only confuse the brain with more early reflections it doesn't need. Everywhere you go, the floor is always the same distance away from you, so it's a reference that your brain can always relate to. Top

John Noll: Reasons for having wood floors: they look good, equipment can be rolled easily, spills can be cleaned up easily, provide a bright sound if needed, sound can be deadened with area rugs.

Ethan Winer: In a studio room, versus a control room, a reflective floor is a great way to get a nice sense of ambience when recording acoustic instruments. Notice I said reflective, not wood, since linoleum and other materials are less expensive than wood yet sound the same. When you record an acoustic guitar or clarinet or whatever, slight reflections off the floor give the illusion of "being right there in the room" on the recording. It's more difficult to use a ceiling for ambience - especially in a typical home studio with low ceilings - because the mikes are too close to the ceiling when miking from above. And that proximity creates comb filtering which can yield a hollow sound. So with a hard floor surface you can get ambience, and with full absorption on the ceiling you can put the mike above the instrument, very close to the ceiling, without getting comb filtering.

Dave Wallingford: I've always preferred wood floors for a few reasons: 1) It's easier to move stuff around, 2) You can always get area rugs if you need them, And the main reason: 3) Pianos sound like crap on carpet.

gvr

I think I had read the same post, upon some further reading, I realised that suggestion for using a hard floor was mostly in context of a recording studio.

same principles apply for an auditorium too. why not?

gvr

I agree that plywood can also reflect sound, but it is has much better acoustical properties than a painted wall. In addition if you create a pattern of holes across the plywood to half the thickness of the ply, you create a great acoustical panel by itself. On top of this if you stick a thick glass wool sheet, you are done.

Though your method of creating acoustical panels is also good, I suggested a ply backing for some rigidity and aesthetics. If you create a panel of some 7 feet by 2.5 feet, it is good to have some rigidity.

Rigid acoustical panels are also available that will do away with these iissues. But then costs are involved.

Cheers

HEY GVR, THANKS! the information you have given here has reinforced my beilef in wooden. One major advantage we have with wood is that even after installation you could still carpet some parts or whole with rugs, which is something not possible the other way around. Not to mention the aesthetics and maintenance.