Acoustic Foam Alternatives

mjmcneese

mjmcneese

Veteran
I was about ready to drop $400 to treat my edit suite with 96' of Auralex, then I did some more shopping and found this...

http://www.cameronpackaging.com/egg_crate_foam.html

I am NOT doing anything super critical...I just need to deaden a room a bit (it's 14'x 14', four walls, 8' ceiling and hardwood floor). So, first I'm wondering why this stuff wouldn't be as good as Auralex. Second, why is Auralex so expensive?
 
your best bet is to go get a ton of great advice on acoustics and acoustical foam.

one of the few things where you will find free advice that is accurate.

www.acoustics101.com

it is done by auralex but they are very upfront about it.

matthew
 
Random padding foam is not the same as acoustic foam, in fact it is mostly worthless for acoustic treatment. It is my opinion that the most economical and effective absorbers are ones you make yourself out of Owens Corning 703 / Rockwool. You can find tons of plans for making absorbers on the net.
 
You could cover your entire room with the [flamable] convoluted foam, and still may not get the same results as a few well-placed auralex pannels.
 
I called two companies that make/sell this eggcrate stuff and they said it was hooey that it's flamable. They said it would melt at 240 degrees, but not ignite. It's make of EPP. In any case, if there's something better, but won't cost me $400-500, I'd be happy. Again, I'm not doing anything critical, I just need my room to absorb a little sound cuz right now I can barely make out words from a VO.

The DIY OC 703 plan sounds like the thing to do.
 
start with the free acoustics101.com

then there is another great book called

"Home Recording Studio: Build It like the Pros"
by ron gervais.

his book is pretty hardcore so you might be better off just using the free acoustics101.com site

Owens Corning has an excellent document that is very close to the information in the above book, it just doesn't go into as much non-technical explanation but you can't beat the price!

http://www.owenscorning.com/quietzonepro/pdfs/NoiseControlDesignGuide.pdf

one last place, they have a decent DIY educational info plus they sell the individual parts or assembled panels.

https://www.readyacoustics.com/

also guitar center has some pretty good prices on kits of auralux stuff.

the owens corning 703 panels are amazing. there is a site that sells them loose with a DIY kit or as complete panels.

you can get them from local building supply places but you have to buy minimum quantities and it is like pulling teeth to get them to look it up and get back to you with a quote.

i haven't tried that rockwool stuff yet but they have it at most home depot's and lowe's.

i'm going to try it out on the ceiling of our basement, directly below our master bedroom because the hvac contrator put the hepa filter box and the outside air exchanger box almost directly below.

but most of the tips in the book i quoted are for building walls/rooms from scratch.

the acoustics101.com and the owens corning 703 stuff is for making an existing space better.

DISCLAIMER: I have no financial incentive or connection with any of the above books or materials or companies. I hate it when someone posts an informative/educational message without mentioning that it is their company/product that they are recommending.

I love it when people like the sound-room.com guy come on here and give info and take suggestions, its just when they aren't up-front about who they are etc.

matthew
 
TVSound, you posted the ebay link while i was writing my mini-novel...

those prices are pretty good but from all the products i've seen where you can tell how thick or how many pieces of 703 they have sandwiched together, they all seem to start with 4" as the minimum.

for example the www.readyacoustics.com folks sell a both the 703 stuff and these bags that you put the 703 in and then you end up with a pretty decent looking acoustic panel...

for what they call their "High Frequency Acoustic" model it is 2" thick

they have a broadband bass trap that is 4" thick and their "Super Sub-Bass" model is 6" thick.

i refer to their site and products most often because they sell both the 703 and they show you directions on how to put together their DIY kit where you just stuff however many panels into a fabric bag.

very few of the other companies even let you know what is in their panel and they never seem to show you much of how its put together.

i guess its because anyone with 703 panels can get some fabric that is fairly acoustically transparent (ie. not denim or canvas!) and make their own panel.

but i don't know if you want to use 1"

i haven't gotten the 703 panels yet as i'm [ ]
 
Generally you have to purchase OC 703 by the box, which will run you around 100$ or so depending on the thickness. OC 703 based absorbers are really far far far far superior to any kind of acoustic foam, at least for absorption. If you need diffusion, there are other options. Most small rooms need absorption, and it is almost impossible to overdo it. The sound in my rooms improved about 100000% after I added all the wall and ceiling absorbers.

It can be kind of difficult to find a local dealer for the 703. You need to call places like heating and cooling wholesalers and specialty insulation dealers. Sometimes if you call and ask for OC 703 they wont know what you are talking about, but if you ask for something like a 2x4 sheet of rigid insulation they figure it out. Lots of insulation places can order this for you,but many don't stock it regularly.


If you are feeling lazy, you might want to check out

http://www.readyacoustics.com/

They make fabric bags that are the right size to stuff with OC 703 sheets. I have a nice sized multi-room studio and I built about 10 wall absorbers with wood and OC 703, and did the ceiling and a couple of spots on in the control room with the bags from ready acoustics. Make sure they have what you want in stock, because in my case the stuff was backordered and took a long time. They may have their pipeline fixed up now, who knows :)

You can make out one of the red ready-acoustics bags in this photo of my control room
377197320_2ec2509e8b.jpg


I see that in-between posts matthew already mentioned ready acoustics. The units pictured are the 6" absorbers. I have three of them on my walls in my control room, and two of the 4" absorbers for the ceiling.
 
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When I was setting up my studio I found this place on ebay which has great auralex look-a-like products for a lot less (although they call it acoustic sound-proofing foam it has nothing to do with sound-proofing but rather sound treatment):

http://stores.ebay.com/Foam-Factory-Inc_Acoustic-Sound-Proofing-Foam_W0QQcolZ4QQdirZ1QQfsubZ7QQftidZ2QQtZkm

I used a lot of the thicker pyramid types and the corner bass traps this company sells. And then for diffusors, something like this:

http://cgi.ebay.com/Auralex-TFusors-A-MUST-for-All-Studios-NEW_W0QQitemZ220108427205QQihZ012QQcategoryZ113484QQssPageNameZWDVWQQrdZ1QQcmdZViewItem


In general what you need to do is put deadening in front of you and diffusion behind you. You're trying to break up the waves bouncing off of parallel surfaces. Ceiling usually takes diffusion.

By in front of and behind I mean: considering the position where you will be sitting and monitoring in the control room or where someone would be performing in a recording studio.

I put 4 auralex diffusors on the wall behind my monitoring position and a bunch of the pyramid foam on the surface of the wall in front of me. I can't tell you how much this helped and it looked great too. You'll want to stuff the auralex diffusors full of some fiberglass insulation as they are hollow too.

You don't want it too dead in there, just break up enough of the surfaces so the room reverberation is cut down.
 
not to hijack this but, would the 703 stuff be good as a portable solution? are the panels heavy? I want to build some sort of a sound right that i can move around for the few times when i need to record audio in my home
thanks
 
703 sheets are not particularly heavy, but they are only semi-rigid and kind of brittle, so to be portable the panels you make would need to have a wood frame and possibly some sort of hard facing to prevent damage.
 
Once they are wrapped 703 are very portable. Not as easy as blankets but if you have a cart they are simple to lug on and off set. They do take a beating when being used on set and you will have to eventually have to replace them.

That's a cool find on those custom 703 bags Matt. The price on 703 has dropped quite a bit since I bought mine 6 years ago at $250 for 12 2' 703.

Cheers
 
Matt, Tigeba,

Thanks so much for your plug.

You know making porous absorbers is pretty easy even if you want to go completely DIY. I created a video tutorial that shows anyone how to make a great bass trap with materials you can find at any hardware store: Bass Trap Tutorial

Here is some additional information on how and why these absorbers work and what they are: Bass Traps Explained


If anyone has any specific or general questions about acoustics, acoustic panels, etc... please let me know and I will assist how ever I can.

Cheers mates!





AVS Bass Traps Sale
 
i belive that most of the foam stuff is for diffusing vs. the 703 which is for absorbing.

my local owens corning dealer (who is primarily a building supply company, tons of plywood, 2x4's and regular pink stuff) finally got me a quote on the 703 panels in 2" thickness, un-faced.

have to buy one box minimum (12 panels and the panels are 24"x48")

i ordered two boxes, the panels were just over $10 each and i don't even have to pay shipping!

so i'm going to use a combination of ready acoustics bags and the new chameleon framing kit.

definitely do your research!

owens corning has some great pdf's with all the info you need...

http://www.owenscorning.com/quietzonepro/pdfs/NoiseControlDesignGuide.pdf

like the 703 panels...

(1) 2" panel is good for higher freq.
(2) 2" panels are good for lower freq
(3) 2" panels are good for really low freq, commonly referred to as bass traps.

on page 21 of the owens corning pdf i pasted above, just one 2" sheet of 703 will do a really good job of blocking things from 500-4000 hz.

but to make a dent in sound/vibrations from 250 hz. and below you need to double or triple the amount of mass you put between you/your mic/your ears and the noise/sound source.

one thing that has come up in virtually all of the test results i have read about the 703 panels and similar materials is if you mount it away from the wall with an "air space" the NRC (noise reduction coefficient - basically a way to measure how much sound is absorbed by a particular material ) goes way up for things 500 hz and above.

this is why having a mixer like the 442 which has a switch to let you do a high pass where you can choose to high pass (low cut) frequencies between 80hz and 240hz.

the schoeps cmc6/mk41 is a great mic but with a less than super experienced boom-operator it can pickup a LOT of handling noise.

a nice side effect of adding the CUT-1 filter was that the handling noise pretty much disappeared the first day i added the cut1 to the mic.

matthew
 
I just picked up enough 6 inch thick styrofoam insulation left over on a construction site to completely sound proof my recording studio. The foreman on the job was saved the hassle of having one of his guys haul it away for a refuse fee. Most of the new construction in the northwest is leaning toward styrofoam in the ceilings... When you see the framing getting sided with particle board you are about a week away…

Kind Regards,
Teague
 
I can tell you what we did. First there are a few different kinds of things that all sort of fall under "acoustic treatment" and a lot of the "this is junk use X" has to do with people not wanting/ needing the same things. Sound proofing is a different issue all together.
So assuming your not trying to sound proof the room the next two things are dispersing and absorbing. The odd shaped plastic and wood panels and the classic egg cartons are dispersers. THe breakup flat surfaces and make the room less boxy and generally breakup standing waves and help even out the response in the room. Absorbers just suck out some of the energy and make it more dead.

The fiberglass suggestion above is pure absorption, and a very good one. The problem is that you probably don't want a totally dead space so you have to be careful with how much you use fiberglass. Acustic foam absorbs a bit and disperses a bit. You see it in small spaces and editing rooms mostly. I haven't seem it in either large mix stages or recording spaces, though I'm sure it's out there.
What we did for a foley room that is pretty small (~10' square, one wall is almost all a big double glass sliding door, one wall has a large control room window and the celling is slanted) was to cover two walls with felt packing blankets and then use eggcrate foam over that. The room before sounded very "roomy" and was almost bathroom like in the brightness. The packing blankets killed most of the bathroom ness but it was still very "boxy/ roomy". THe eggcrate foam killed the boxyness and right now it is a very neutral space. It can be out doors or indoors. If we open the sliding door the hard surfaces of the next room make it very interior.
We use egg crate foam mattress's. THey work fine and are not a fire hazard. Acoustic foam will look better longer - its a better material. THe bedding foam will darken with age and after awhile (5-15 years depending on exposure to sunlight and air) will start to disintegrate. The Acoustic foam will hold up a lot longer.
You could also use fiberglass batting and cover it with cloth. We wanted to be able to tune the room and I didn't want to deal with fiberglass.
 
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