Acoustic Rated Carpet?

Posted: Wed Aug 20, 2008 6:37 am

The theater I do briefcase work at is under new ownership. The new owner is wanting to replace the drapery material in the old movie theater.

The problem is, that someone is telling him that they make and can install an acoustically rated (whatever THAT means, right?) carpet on the walls.

I know that carpeting has been used in movie theaters for quite some time, but just trying to double check on quality manufacturers and overall things to check, and watch out for.

Thanx!

Posted: Wed Aug 20, 2008 6:44 am

It doesn't exist. Absorption characteristics for various types of carpet are available, the common thing being no mid range or low end absorption.

Andre

Posted: Wed Aug 20, 2008 9:01 am

I dunno Andre... There IS one "acoustic carpet" that I found... it's a polyoelephine indoor/outdoor carpet sold in the boating industry...

Not sure how much is believable... but it's there.

I told the owner to find a similar weight FR or IFR material, and he came back to me with this carpet business.

Posted: Wed Aug 20, 2008 2:45 pm

Is this a real theater ? A public space ? Ain't that acoustical fire rated, what you meant ?!?

Posted: Wed Aug 20, 2008 6:14 pm

it's an old movie theater built in the 40's that's been somewhat renovated for live music...

It needs a LOT of work to really get cleaned up acoustically... and needs a new HVAC system, but he's going to wait to do the replacement of that... but in the meantime...

He wants to replace all the drapery material on the walls... and he's going for as cheap as possible.

My guess is, someone who knows nothing about acoustics has this stoopid misconception about sound and is saying that this carpet is acoustically rated.

Like I said... I've seen carpeting on the walls in new movie theaters to knock down some flutter... just not sure if they actually had a rated carpet or not...

Posted: Wed Aug 20, 2008 6:39 pm

What does he mean by "acoustically rated?" Anything can have its acoustic properties tested and test results used to calculate such as NRC. That does not mean any sort of "rating" as to its applicability for any specific acoustic application. Egg cartons have been tested.

What sort of substrate will they mounted on? Just one question that comes to mind.

Andre

Posted: Wed Aug 20, 2008 7:08 pm

That's what I was wondering too, Andre.

In all the forums I frequented, I have NEVER heard of anyone trying to use carpet, much less one that's "rated".

I thought maybe this was some closely guarded commercial secret or sumpin'...........

Posted: Thu Aug 21, 2008 5:08 am

One thing I know for sure.... I'm not sure you can use carpet in a theater unless it is fire-rated.

Second thing I know.... carpet absorbs medium and high frequencies and you already have absorption at high frequencies due to the air in the space. My best choice would go for perforated panels for medium frequencies and diffusers for high frequencies (now that we have surround and all that crap !).

More on carpet acoustics at http://www.carpet-rug.org/technical_bulletins/0002_Acoustical_Characteristics.pdf

Regarding fire safety.. http://www.carpet-rug.com/technical_bulletins/9811_Flammability_and_Carpet_Safety.pdf

Problem is that he does not have money I think... to make the correct choices, am I right ? Placing carpet directly into the walls will just make things sound muddy.

Third thing I know... it the space exists you should make measurements in it. It would be even a good idea to make an acoustical model of the room. I could this for an affordable price but it should be a good idea to make measurements to fine tune tune the model.

Posted: Thu Aug 21, 2008 8:31 am

Max,

I would have to see the specs on the carpet -

First is the point Andre makes - which relates to fire rating.

Not only must it be tested - but it must specifically be tested as a part of a wall assembly.

The only carpet I personally know of that this has been successfully done with is Berber carpet - which is even then limited as to the total amount that can be placed on walls (as a percentage of the wall surface).

And Berber carpet is NOT an acoustical carpet.

BTW - I covered this in the book.......

Rod

Posted: Thu Aug 21, 2008 9:30 am

OK - I have been doinf some research, and it seems there are a number of companies manufacturing acoustic carpets...... BUT - everything I have found is for automobile carpet -

American Terminal manufacturers Auto acoustic carpet...

A company called Noiseout is selling an acoustic carpet as a solution for your home - yet the fire test it lists for the carpet is MVSS 302 - which is the Motor Vehicle Safety Standard 302 - so they are nuts to be selling it to people for their houses.....

UGN also manufacturers acoustic carpet - however this from a newclip -

Quote:

UGN, Inc., the leading producer of automotive acoustic, interior trim and thermal management products, announced plans to open a multi-million dollar production facility to produce the company's first RIETER ULTRA LIGHT(TM) acoustic carpet system for North American Japanese transplant automakers.

So again - auto carpet

OK - So Autex (Composition) and Acoustica (Echostop) manufacture Wall Fabrics (although adds call then wall carpets) for acoustic applications - but the NRC for the Echostop is only 0.4 and for Composition it is probably the same (they are both polyester fibers)

One point I would make here is this - I do not see any of these products tested in accordance with the requirements in the US for wall coverings....... and that would be an issue.

The US is does not accept testing that certifies this for use in either Europe or Austrailia (which are the results I am getting )

enjoy,

Rod

Posted: Thu Aug 21, 2008 11:42 am

Those NRC values from carpet are ridiculous for such application in a theater. Perforated panels have at least the double of the NRC.

Posted: Thu Aug 21, 2008 4:24 pm

Glad to see my suspicions are hereby confirmed!!

I'll see how far he wants to go to keep the place sounding nice and tight and dry.

Thanx!!
Max

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