Room Reverb Problems

How to use REW, What is a Bass Trap, a diffuser, the speed of sound, etc.

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Thatoneguy
Posts: 42
Joined: Tue Mar 01, 2005 6:24 pm
Location: Toledo Ohio, USA

Post by Thatoneguy »

I read through the article you pointed out, nice suggestions.

1) How big of panels would you suggest for the room.

2) is this a good layout of how I should do the panels. . .

a - build square 1x4 frame
b - leave 1" air on the back
c - 1" of wool
d - 1" insulation
e - 1/2" of air
f - cover it all with a layer of plywood. And seal it all

3) Is it ok if I nail board into my closet doors/walls, to make a sort of hook to hold the panels up. Line it with a little bit of foam to prevent rattling. Will this do the job just as well? This way the panels arn't permanent for removal, and so I can have easy access to the closet as well.
knightfly
Senior Member
Posts: 6976
Joined: Sun Mar 16, 2003 11:11 am
Location: West Coast, USA

Post by knightfly »

1) How big of panels would you suggest for the room.

Typical absorbent materials come in 2' x 4' panels; this is also about as small as will do much. For SOME small, early reflection treatments a 2x2 foot panel can help. For others, 4' x 6' is better. Side reflections, half-way between speaker and your head on side walls, you might only need 2x2's but probably 2x4's - for the front of the closet, more like 4x6 foot - same for a "cloud" over the mix position. Corner broadband absorbers should be MINIMUM 2 feet wide, 3 is better. Across wall-ceiling intersections, diagonal 2' wide works.

2) is this a good layout of how I should do the panels. . .

a - build square 1x4 frame
b - leave 1" air on the back
c - 1" of wool
d - 1" insulation
e - 1/2" of air
f - cover it all with a layer of plywood. And seal it all


No, the minute you use a plywood back or front you've just changed it to either a limited-absorption panel or a panel-type bass trap (narrow frequency range, probably more damage than good unless it's calculated correctly AND you have a problem at that particular frequency AND it's placed in exactly the right spot in the room)

Better just to use as thick absorbent as you can afford in that frame, use either steel angles for corner braces or use relatively small wood corner gussets, and cover the absorbent with your favorite cloth. Spacing this further away from a wall will increase the lower frequency range of absorption. A solid-backed panel will act totally different.

3) Is it ok if I nail board into my closet doors/walls, to make a sort of hook to hold the panels up. Line it with a little bit of foam to prevent rattling. Will this do the job just as well? This way the panels arn't permanent for removal, and so I can have easy access to the closet as well.

I've posted a sketch of one similar method some time ago -

http://www.johnlsayers.com/phpBB2/download.php?id=1173

Before you get started on ANY of this, it wouldn't hurt to find out about any existing rattles in your room so you can kill them before anything else is added - if you have a PC, you can use this

http://www.moonaudio.com/softwar5.htm

and sweep the frequency of the audio oscillator through the audio range at about 90 dB level, listening for rattles - any you find will need to be killed, either by removing the object, dampening it with foam, duct tape, etc... Steve
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