John Sayers' Recording Studio Design Forum Archive

Hey guys,
Just thought I'd share this. Found this cotton fiber insulation, it's GREEN (aka made from recycled materials), and has a better STC rating than roxul or the auralex mineral fiber stuff, and is fire rated and everything. About to build a room in Los Angeles and am definitely gonna try it.

Check here -
http://www.soundaway.com/Ultratouch_Insulation_s/79.htm

If anyones used this stuff, let me know what you think!

Maybe I'm just a little confused here, but how can insulation have an STC rating when it doesn't actually block sound very well at all? Maybe I'm just slow today, but I'm having trouble understandng how insulation can have an STC rating al by itself.

I downloaded the product specs from that web site, and it claims that a 3.5 inch layer of that cotton stuff has an STC rating of 45, which makes it about twice as good as two layers of 5/8 sheetrock on studs! That's a pretty amazing claim! (But read the fine print....)

So if I take those specs at face value, I could build my studio from a couple of layers of this cotton stuff and nothing else? WOW! Cool! So I can throw out all my plans, and just string up a couple of bits of cotton trash, and I have a world-class studio, for just a few dollars! What an amazing acoustical breakthrough!

( It's a pity that there is no "tongue in cheek" emoticon here, 'cause I think I need to use it abut now! )

Please excuse me for being just a little bit skeptical of such claims....

Maybe they just forget to mention that they put this stuff inside a wall in order to test it for STC?


- Stuart -

Here is some discussion on it.
http://www.gearslutz.com/board/bass-tra ... tions.html

Andre

Thanks, Andre. Interesting link! It just reminds me of how far I still have to go to understand acoustics. Just when I thought I was getting a handle on how bass traps work!!!!

Anyway, I'm not disputing the absorption properties of the cotton: I'm commenting on the manufacturer's claim that the cotton has an STC rating of 45. I just don't see how that can be true! It would have to be mounted in a wall in order to have an STC rating like that, and you'd have to specify what kind of wall. I cold glue a sheet of paper to a rendered brick wall, and then claim that the paper gave me an STC rating of 45! That's my beef here. Questionable claims with the details hidden in the fine print.

Yeah, if you read the fine print they do in fact say that it was tested in accordance with so-and-so standard, but I'm just ranting about how misleading that kind of advertising is. You could make the exact same claim for bubble-wrap or egg-crates having an STC rating of 45 if you built the right wall to put them in!

Curiously, they don't seem to publish any independent lab tests about their products, which is a huge red warning flag for me, right away.

Sorry, I'm just ranting here. . . . Been a tough day.... I'll stop now!


- Stuart -

Soundman2020 wrote: I'm commenting on the manufacturer's claim that the cotton has an STC rating of 45. I just don't see how that can be true! It would have to be mounted in a wall in order to have an STC rating like that, and you'd have to specify what kind of wall. I cold glue a sheet of paper to a rendered brick wall, and then claim that the paper gave me an STC rating of 45! That's my beef here. Questionable claims with the details hidden in the fine print.

Yeah, if you read the fine print they do in fact say that it was tested in accordance with so-and-so standard, but I'm just ranting about how misleading that kind of advertising is. You could make the exact same claim for bubble-wrap or egg-crates having an STC rating of 45 if you built the right wall to put them in!

Total agreement.

Andre

Related to the UltraTouch vs Fiberglass... it is know that the R value of fiberglass batts will not go down over time through settling... but, does anyone know if the same is true for the Ultratouch Natural Cotton Batts? I am thinking about using it, but, don't want to have a reduction in insulation over time.

Tom

I used recycled cotton/hemp batts inside walls, and every engineer in here has been impressed. (that's what we're talking about here right, inner wall insulation? Anybody out there gluing 703, Auralex, or loose fiberglass batts to the outside of their walls and expecting sound absorbtion, rather than reflective diffraction?) If you like breathing carcinogenic formaldehyde tightly sealed in an insulated studio for hours on end, 703 , Auralex, and commercial insulation will give you a glue-sniffing boost to creativity. If you prefer oxygen to fuel your brain and body, try the cotton batts inside walls, and frame some of them and cover with cotton/hemp canvas for reflective panels. Wall coverings are for reflection damping, sound reduction takes mass, which would be your double walls and inner insulation. Apples and oranges. Try breathing air instead of industrial chemicals while making music, see how that effects energy and creativity.

Anybody out there gluing 703, Auralex, or loose fiberglass batts to the outside of their walls and expecting sound absorbtion,

Well, GLUING it to the walls wouldn't be a good idea, for sure! But mounting 703 properly works wonders for in-room absorption, especially with inside-out walls, slot resonators, bass traps, FRP absorption, and suchlike. It's hard to see how you could build a superchunk without having the 703 inside your walls....

...tightly sealed in an insulated studio for hours on end...

Well, that is kind of what a good HVAC system is supposed to do: keep fresh air flowing through the studio, in sufficient quantities and at suitable temperature / humidity, to keep people, instruments and equipment in good working order! HVAC is a rather important part of good studio design / construction.

... and frame some of them and cover with cotton/hemp

Hemp is a bad idea for some people: They seem to be allergic to it.

sound reduction takes mass, which would be your double walls and inner insulation.

Actually, the purpose of "inner insulation" in an MSM wall is not to add mass. It damps standing-wave resonance inside the wall, and more importantly it drives down the resonant frequency of the MSM system. The small amount of mass that it adds to the wall is hardly relevant, unless you use stuff that is way to dense, in which case you are just wasting your money anyway, and also run the risk of creating internal flanking paths.

- Stuart -

"If you like breathing carcinogenic formaldehyde tightly sealed in an insulated studio for hours on end, 703 , Auralex, and commercial insulation will give you a glue-sniffing boost to creativity."

Hogwash. There is nothing to support this statement other then you saying it. Based on that, you should amend or completely remove it from this forum unless you can provide adequate support, which is going to be difficult to do.

hi,
I am from Australia. I am building my own house and for now i have completed my bed rooms and living there with my furniture including bed with cotton bed sheets and sofa. I did not use cotton fiber insulation before, this post is really informative for me.

Is it easy to work with recycled cotton/hemp batts? I have a kid with asthma so I'm still unsure if this one's good to use.

not sure if its easier to work with the natural fiber products versus fiberglass/mineral wool. in reviewing the references provided, one of the concerns is the binding agents used in the natural fiber products - apparently manufacturers are not always forthcoming on the chemicals used. not that that may have anything to due with using them as far as health safety goes. ultimately, any product selected for absorption should be contained - in walls, inside cloth covering etc. and it's a good idea to unroll the product (or unstack them) and let them air out.
one thing i noted in this chart: the fiberglass/mineral wool seems less of an explosive hazard compared to natural fibers and wool

one other thing about natural fibers - sometimes they are food for insects and other pests. Borate as a fire re-tard-ant is also useful in keep those at bay.
here's a link to some more information. checking under building environments.
https://www.epa.gov/expobox/about-expos ... s-handbook

There was a study which found that cotton fibres rot slowly in the lung, taking up to 18 months. Glass and Rock fibres dissolve in body fluid in a fortnight.