Acoustic Treatment-Wall Panels As Artwork

bpape · « **Reply #20 on:** 13 Sep 2006, 11:48 pm »

Cotton, as long as it's a relative loose or thin weave, will be anything but reflective. Polyester and very tight weaves are a different story. I use cotton based cloth all the time and even put speakers behind it. If it will allow speakers to perform without even moderat deformation of the frequency response, it will work just fine with NO worries at all about reflections.

Lightweight muslin (100% cotton) is almost as acoustically transparent as GOM FR701-2100 series cloth for 10% of the cost - as long as you don't mind white or off white.

Bryan

DSK · « **Reply #21 on:** 14 Sep 2006, 12:03 am »

Yes, anything with a sufficiently open weave should be fine. Someone once told me that a quick test while perusing the various rolls of material is to pick each one up and lightly breathe/blow through it. The ones that allow you to feel most breath on your hand on the other side are the most open weaves. It won't say anything as to the reflectivity of the actual material, but it will indicate the openness of the weave.

launche · « **Reply #22 on:** 14 Sep 2006, 01:34 am »

Quote

... But some of the posts I read gave me a bad impression of the burlap and I was running around trying to find alternatives...

Yes I did mean aesthetically speaking but I find the burlap to be attractive.

I was doing the blowing test with various fabrics, the security guys watching me from the ceiling cams must have been having a nice laugh, thinking look at this sick fool tasting the fabrics

Oh yeah, burlap tastes nasty.

Gonna try to pick up the mineral wool on friday. The wife me going to baby showers and birthday parties his weekend but hopefully I'll get a chance to do some work on them this weekend and down will come the "home decoration" type pseudo treatments and in with something more appropriate.

DSK · « **Reply #23 on:** 14 Sep 2006, 01:45 am »

Quote from: launche on 14 Sep 2006, 01:34 am

I was doing the blowing test with various fabrics, the security guys watching me from the ceiling cams must have been having a nice laugh, thinking look at this sick fool tasting the fabrics Oh yeah, burlap tastes nasty.

LOL. Yes, I can just hear the two security guards as they watched you ...

"Hey Ralph, looks like we got ourselves another sicko here! ...No.... wait.... even worse .... I think it's one of them audiophiles".

MaxCast · « **Reply #24 on:** 14 Sep 2006, 10:51 am »

I wonder if these guys can do anything for good looking pannels.
http://www.artandaudiofusion.com/index2.html

fajimr · « **Reply #25 on:** 14 Sep 2006, 03:04 pm »

Quote from: launche on 13 Sep 2006, 11:27 pm

I went to another fabric store today and found several colors of burlap (jute). I have seen burlap before but didn't pay much attention. Now i must say it's not perfect but it's actually a nice lokking fabric, especially when view from a few feet away, it can have a very refined look to

I'd have to agree, I was a little doubtful when I bought some but then when I built my bass traps (5 1/2' x 2' using a double layer of 2" 6 lb. mineral fiber) with burlap and a 1" x 4" pine frame looks quite nice actually. My friend suggested that I splurge and get the more expensive pine which I then sanded and stained. I have wood floors and muted green walls so the brown of the burlap contrasts nicely. The guy at the store even suggested that I could dye it although with the starting color at light brown, I imagine the choices are fairly limited.

No photos but I might be able to get a camera if people are interested.

launche · « **Reply #26 on:** 14 Sep 2006, 10:41 pm »

Please post pics, I know I'd be interested in seeing how your turned out. That design sounds like something I was thinking of trying myself.

I just picked up some mineral wool today. Six 2" 2x4 sheets of 8lb mineral wool. 8lb was all they had, I'm sure that good for the corners but is it too much for the front wall behind the speakers. In the corners I was thinking of using 4" 8lb pieces. And I wanted to do to 2" 4lbs pieces with a 2" air gap on the front, side and rear walls.

Would the 2" 8lbs pieces suffice on the front, rear and side walls as opposed to the 4lbs pieces. Would all 8lb pieces be too much midrange freq. absorbtion?

Thanks

fajimr · « **Reply #27 on:** 16 Sep 2006, 01:29 am »

Quote from: launche on 14 Sep 2006, 10:41 pm

Please post pics, I know I'd be interested in seeing how your turned out. That design sounds like something I was thinking of trying myself.

let me see if I can't grab the camera from work this weekend and then get some photos up.

yes, I think 2 layers of 2" would work well in the corners. For my project, I used 1 x 4 pine (an 8 foot piece) and then cut 2 feet off of each end leaving me with 6 feet. I wanted 'legs' at the bottom so what I did was cut one piece of mineral wool at 18" (its actually easy to cut with a sharp utility knife and a metal carpenter's T). I then put the regular 4ft long piece with the 18" piece and laid another 4 ft piece and 18' piece on top, alternating the short pieces. I sprayed a bit of adhesive around the perimeter for good measure... I then wrapped the burlap (which I ironed first to get all the wrinkles out) around the mineral wool and then sprayed the back with adhesive again to hold the burlap down (as of this writing there is still a large 'open' space on the back that I plan to cover with another piece of burlap). I then simply slid the frame over it... the corners were really tight (actually it was all pretty tight but especially the corners where I put L braces on the inside) as I didn't realize that the width of the mineral wool was 2 ft 1/8" + burlap.... but it actually worked to my advantage as I didn't need to glue the insides of the frame. The corners did push in a bit but I simply pushed them back out from the rear (it compressed the mineral wool in the rear corners but you can't really tell).

Like I said before, I think it pays to get the nicer pine and then sand and stain after you assemble, I simply used an inside L bracket, screws and some glue and they are plenty solid. I'd like to add some feet as they are currently leaning against the wall ever so slightly- just enough so that they don't fall over into my speakers

I'm no carpenter by any means but did have the use of a friend's garage and high powered tools

On caveat- the seam where the two pieces of mineral wool does show slightly. On one side I but the smaller piece on the bottom- Good! On the other one I wasn't paying attention and put the smaller piece on the top. You can tell if you are looking closely.
Also check out the burlap- mine had some pretty major warp damage (the threads that run through the weave)... It's noticable but the yellow mineral wool doesn't show through.

If you are still wondering about the effect of density on absorption, check out ethan's primer on his website. lots of good stuff there.

good luck...

lonewolfny42 · « **Reply #28 on:** 16 Sep 2006, 05:52 am »

Whenever I see threads like this, I think back to the fine job that PeteG did on building his DIY treatments...with photo's. Here....take a look......

Papajin · « **Reply #29 on:** 16 Sep 2006, 08:03 am »

I've always wondered if you could find a tapestry with an open enough weave to turn into a DIY panel...

gjuodenas · « **Reply #30 on:** 16 Sep 2006, 01:01 pm »

One thing that has not been addressed is the air pollution created by putting fiberglass or mineral wool behind an open weave fabric. Anyone that has handled either material knows that any physical movement of the material releases particles into the air. I am sure breathing fiberglass or mineral wool is very bad for your health. I have gone to great lengths to design an acoustically transparent highly effective filter to place between the acoustically transparent cloth and the mineral wool in all of the absorption panels we sell at SRLAudio www.srlaudio.com. I can't in good conscience sell anyone an absorption panel that will affect their or their family's health. This is a topic that does not get much discussion and I believe is a dirty little secret of the acoustic panel business. I urge anyone considering putting absorptive acoustic panels on their walls to seriously consider this topic. That also makes the case for diffusion panels which do not have this problem awfully attractive.
Thanks for letting me spout off.
George Juodenas

fajimr · « **Reply #31 on:** 16 Sep 2006, 02:17 pm »

Quote from: lonewolfny42 on 16 Sep 2006, 05:52 am

Whenever I see threads like this, I think back to the fine job that PeteG did on building his DIY treatments...with photo's. Here....take a look......

I actually used this as a reference point although I am no where near as good as pete concerning my carpentry skills.

Housteau · « **Reply #32 on:** 16 Sep 2006, 04:09 pm »

As far as the health risks go, here is the official word from the American Lung Association. As you can see a lot of the previous fears had been overstated.

www.lungusa.org/site/pp.asp?c=dvLUK9O0E&b=35439

Dave

gjuodenas · « **Reply #33 on:** 16 Sep 2006, 05:05 pm »

Dave,

I looked at the link you provided to the lung association.

Here are some sentences copied from that link:
Make sure all installed insulation is never left exposed in an occupied area. Direct contact with fiberglass materials or exposure to airborne fiberglass dust may irritate the skin, eyes, nose and throat. This is not an allergic reaction to the material. Breathing fibers may irritate the airways resulting in coughing and a scratchy throat. Some people are sensitive to the fibers, while others are not.

There is some current thinking that the cancer warning label on fiberglass may be overstated but the warning has yet to be changed. However, are you going to test everyone in your family and your friends to figure out who is sensitive, who should not go in your room?

George

bpape · « **Reply #34 on:** 16 Sep 2006, 05:31 pm »

If a the cloth is attached to the panel with a spray adhesive and you don't go banging into it, moving it every couple days, poking it, etc. - you'll have no shedding. If you're still concerned, a thin layer of cotton or poly batting in front of the fiberglass before the cloth wil filter just fine and not change the absorbtive characteristics at all.

Bryan

gjuodenas · « **Reply #35 on:** 16 Sep 2006, 09:03 pm »

Bryan,

You are correct, that is a fine solution. Just as a note, I have seen recording consoles covered with a fine particle fiberglass in rooms where no precautions have been taken. It is much more difficult to assess particles in a residential environment. You usually do not have big flat surfaces in a listening room. Even being most careful, I don't know about anyone else but I have not been able to handle fiberglass or mineral wool even gently without raising a cloud of particles into the air. Also, everytime a door is opened or the air handling system comes on there is a pressure change in a room and it slightly moves the surface of exposed absorption material.

George

fajimr · « **Reply #36 on:** 16 Sep 2006, 10:11 pm »

interesting discussion... from what I had garnered, as long as you didn't move it around there wouldn/'t be any (o.k. not much) airborne particles floating around... I certainly did take precautions when cutting it and used a mask, gloves and long sleve shirt.

Bryan- great idea about the cotton layer! I might have to try that with the next set of first reflection absorbers.... thanks!

just as a point of clarification: when you said attaching the the cloth with spray adhesive, did you mean over the ENTIRE surface of the panel (and thereby creating a layer of adhesive to keep the particles in place) or simply around the back where one might fold over the cloth?

rajacat · « **Reply #37 on:** 17 Sep 2006, 02:48 am »

Does cotton work very well as an acoustical panel? What about dacron or duck down? I too worry about micro particules being injested into lungs.

Raja

bpape · « **Reply #38 on:** 17 Sep 2006, 03:02 pm »

Even just a light spray of adhesive across the front will do the trick and not restrict or change the gas flow characteristics of the absorbant material.

George, I agree completely. When you handle it, there will be some shedding. I guess my point was that if you put them up and leave them alone, after they settle, there will be very little if any shedding. If they're going to be put up and taken down all the time, that's a very different story.

Raja,

There are cotton products made specifically to be acoustical absorbers and come in 1.2lb, 1.5lb, 3lb, and 6lb densities.

Bryan

BradJudy · « **Reply #39 on:** 17 Sep 2006, 04:48 pm »

Bryan,

Do the GIK products have a layer of batting to reduce shedding of the mineral wool?