building your own absorbers

[spiderman2812]

I'm going to build my own absorbers and was wandering what you guys and gals think is the best fabric to cover them with. I read somewhere that burlap is goo and that some fabrics reflect alot Any suggestions?

[c7sus]

I used hemp muslin.

[apl]

A quick test is to see how easy it is to breath through. Of course, the people at the fabric shop might call the cops when they see you getting all intimate with their wares.

[DDev]

Originally Posted by spiderman2812

I read somewhere that burlap is goo

I used burlap and have never seen any evidence that it degenerates into a sticky, slimy substance

But, seriously, there are 2 things you need to keep in mind with whatever fabric you choose.

1. Is it acoustically transparent (to determine, the aforementioned breathing test will suffice).
2. Does the fabric have a fire rating? You might need to at least treat the fabric with a fire retardant if it is not pre-treated.

Darryl.....

[phatmass]

What's the deal with all this fire rating talk all over the place? Do studios start on fire a lot or something?

[punkin]

Not that they start on fire alot but IF you had some equipment malfunction or a dumb ass with a cig or what if...just what if Kieth "the human chimney" Richards came over or something and touched off one of your home made super duper unprotected, non-fire rated absorbers...charcoal and toast served up in a hurry! And just wait until the insurance company finds out what you had done...OMG!

I had a buddy who thought he knew what he was doing when he set out to sound proof a basement home theater. Kick ass isolation but, the cheap rubber matting material and glue he pasted inside the wall and ceiling joists will kick out some deadly fumes if the joint ever goes up. He'll be dead before he ever realizes the place is on fire.

Bottom line...better safe than sorry...or worse. Besides, the rated material and or getting them treated, won't cost that much more.

[RICK FITZPATRICK]

Think about it. VERTICAL fabrics will burn in a NEW YORK SECOND. Ever seen pictures of curtains on fire? And no, studios arn't prone to fires anymore than another type space. However, how many spaces do you see with fabrics on almost all the walls and even the ceiling. A few thoughts that comes to mind is..
PERMITS AND INSPECTION= INSURANCE....forethought....hindsight is 20/20....irresponsibility...3rd degree ...dripping burning nylon... smoke alarms....airtightness... DIY wiring.... Lever latchsets..egress emergency lights... battery powered exit light...flashlights...earthquake...catastrophe... Fire extinquisher.... untested foam...nightclub fire....death.. shall I go on
fitZ

[apl]

Originally Posted by punkin

...deadly fumes...

That's why I'd avoid plastics and synthetic fibers.

[famous beagle]

Can you get fire retardant spray at home depot? Or better yet Walmart?

[pdadda]

Better yet Walmart??? Don't support those douchebags!!!

[punkin]

I hope you don't think we're trying to bust your chops on this but we'd rather keep you and your's on the forum and on the planet for awhile. When it comes to construction and personal safety,...the golden rule is, if you don't know, get with a pro that does.

Sometimes it seems simple enough to add an extension cord or put egg-crate on the wall to get the job done but too many people have been hurt and obviously, you've got web access so take the time to do a little homework. Inspite of the ball bustin' your getting here, you're getting a little education too so hang in there with us while we rant.

I don't know if you can get these items at Home Depot or Walmart but here's a few places I pulled up on the net in a quick search. I'm sure there are others...and probobly better.

http://www.natfire.com/
http://www.dharmatrading.com/html/eng/1693-AA.shtml
http://www.flamestop.com/
http://www.fabrics.net/fireproofing.asp (this one has some generaly good info)

Keep checking. Search for flame or fire resistant cloth, flame or fire resistant fabrics, and fire or flame resistant treatments.

Maybe we could get Ethan to chime in here since he's got a lot of experience in this area.

[Ethan Winer]

Punkin,

> Sometimes it seems simple enough to add an extension cord or put egg-crate on the wall ... Maybe we could get Ethan to chime in <

My answer may surprise you. I agree about the egg crates for sure, and likewise for packing foam. But thin fabric - not heavy drapes! - don't have much mass to create a lot of smoke or sustain burning. Muslin is very thin and light, so I'd think it would burn off pretty quickly. This came up just yesterday in my Acoustics forum at MusicPlayer.com, and below is my post from that thread.

--Ethan

When we had our MiniTraps fire tested I asked the rep at the testing lab if she thought the fabric on the front surface might keep us from getting a Class A rating. She told me that thin fabric is never a problem because it is consumed almost immediately and contributes very little to both smoke and flame spread. So what matters most is apparently what the bulk of the panel is made from.

[RICK FITZPATRICK]

As usual Ethan, great info. Thanks. Question though, so a Class A fire rating can simply mean....nothing was done to fabric...its the same no matter? Man, that sounds just like the pink tuna... Guaranteed Class A cause we did nothing. Anyway, thanks Ethan.(this world amazes me sometimes)
fitZ

[Ethan Winer]

Rick,

Up early this morning, eh?

> so a Class A fire rating can simply mean....nothing was done to fabric...its the same no matter? <

I'm not a flammability expert, but I do know that the two things they test are 1) how much smoke is created, and 2) how the flame spreads from one end of the Device Under Test to the other. We had to send the lab four MiniTraps, which they put end to end in a "horizontal chimney" and blasted them with 980 degrees. They measure how much smoke is created, and also how far the flame travels and how quickly. You can see the full lab report from a link at the top of the Product Data page on my company's site.

--Ethan

[punkin]

You thu man Ethan...thanks.

[Innovations]

BTW I usually use felt...cheap, 'breathable', and in lots of colors.

[spiderman2812]

thanks to everyone