acoustical treatments

Posted by: MML

acoustical treatments - 03/18/10 10:37 AM

i want to build my own, who has built their own and what materials were involved.
Posted by: fredk

Re: acoustical treatments - 03/18/10 07:38 PM

Depends what you want to do. For trapping, use high density glass (3lb per cu.ft.). Carpet on bare floor at first reflection points. Difusion is a little more complicated.

There are some good articles on treating rooms at

I gave up on my concrete bunker because I don't have the room and I would need to treat a LOT.
Posted by: SirQuack

Re: acoustical treatments - 03/19/10 08:20 AM

me, owens corning 703, pictures on website.
Posted by: BWeasner

Re: acoustical treatments - 03/19/10 10:53 AM

I used a brand equivalent to owens corning 703

Basic construction info from my HT can be found in a thread on these forums (about 1/4 the way down the page):

I can send you more detailed info upon request
Posted by: Slitman

Re: acoustical treatments - 03/19/10 01:44 PM


I'd be interested in knowing the details of the construction. Unfortunately finding Corning 703 in Markham, Canada isn't so easy.

I also went with a red colour on my walls. Are you noticing much difference in the accoustics now that you have your panels up ?
Posted by: BWeasner

Re: acoustical treatments - 03/19/10 01:54 PM

BIG difference in sound quality. I guess my room is a lot like fredk's...a concrete bunker (laughed out loud at this, never thought of my basement this way \:\) ) After I installed all the drywall in the room, the smallest sounds would echo like crazy. Even dropping a drillbit sounded thunderous.

Now, I hear no echos or muddiness at all in the theater (except for a litte bit of reverb coming from the untreated stairwell, but I don't think there is anything I can do about this). It is nice to be able to have a conversation in that room (no movie or music playing, of course) and not hear your voice echo at least two or three times.
Posted by: MML

Re: acoustical treatments - 03/19/10 02:31 PM

great looking panels!
simple and inexpensive to build
do you think i can get away with shallower ones, say an inch in depth. i prefer a more subtle panel
Posted by: ClubNeon

Re: acoustical treatments - 03/19/10 03:12 PM

The thickness of the panel is directly related to the lower frequencies it can trap.
Posted by: BWeasner

Re: acoustical treatments - 03/19/10 03:28 PM

 Originally Posted By: ClubNeon
The thickness of the panel is directly related to the lower frequencies it can trap.

Exactly! I think that the recommended thickness for the lowest frequencies (bass traps) is AT LEAST 4-6" of fiberglass. ClubNeon, do you know?
Posted by: MML

Re: acoustical treatments - 03/19/10 03:32 PM

is this one of those things that something is better than nothing. i don't think it'll sound any worse with diy panels??....
Posted by: prototype3a

Re: acoustical treatments - 03/19/10 03:57 PM

How do you determine where the panels should optimally be located?
Posted by: ClubNeon

Re: acoustical treatments - 03/19/10 09:06 PM

Yeah, something is better than nothing. Even 4" to 6" is only starting to roll off the lower bass, but it's having plenty of effect on taming reverb of the highs. That said, thinner panels can be used at the first-reflection points along the walls, while thicker ones are placed in the corners.

The first reflection-point can be found by two people. One sitting in the listening position. The other taking a flat mirror along the wall. The "listener" only turns his head to the left and right, while the mirror is moved forward and back along the wall. When the speaker comes into view in the mirror, that's where to place a panel. Also between the speakers in the front of the room, and along the rear wall.

For the corners, if you can afford it. Take enough rock wool panels to stack to the ceiling. Then you cut each 2'x4' panel in half so you have two 2' squares. You divide those squares diagonally so you have triangles with 2' on each side (and a hypotenuse which Pythagoras could tell you the length of). That'll give you four piles of triangles each big enough to reach the ceiling in the four corners of the room. That'll provide excellent bass trapping.
Posted by: Zimm

Re: acoustical treatments - 03/24/10 05:06 PM

Something is absolutely better than nothing. I did a bit of treatment and found big gains from certain small changes, but no gains from others. The key is what small change makes the most impact. For me, (small HT) filling the corner behind the FL and FR made a much better soundstage. Second best was knocking down the 1st order reflections on the sides. That realy improved the focus of vocals and killed some ringing.

Used a difuse plan for the front corners by stacking law books in a fashion to take up the corner and avoid corner loading, but also left triangle gaps between the books so there was no repetitive pattern for the waves.

Hard to explain...