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View Full Version : Would rigid foam insulation help to deaden sound?


Tonelover
01-28-2012, 08:42 AM
Looking to attempt a few band practices here at home. I am already in pretty good shape due to having an isolated location, it's not like I have a neighbor on the other side of the wall. But, just to minimize the bass and drums from carrying outside I am thinking about just covering some of the windows. Unfortunately, 2" closed cell foam is very expensive, one of my windows is quite large. So I was looking at Lowes/Home Depot stuff and about the most workable cheap stuff I could see is rigid foam insulation. I am wondering whether a wood frame, with two layers of rigid insulation and a small gap in-between the layers, to put in front of the wondow would do any good at helping to deaden the exterior noise. I don't know what the sound properties of that stuff is but it's basically styrofoam. Or if anyone has a better suggestion for inexpensive material I'm all ears. Thanks!

Manicstarseed
01-28-2012, 11:52 AM
It should work with dampening the sound transmission. The double layer ensures that. I would be a little concerned what the material would sound like in the room.

disfrontman
01-28-2012, 01:53 PM
Foam insulation of any kind pretty much sucks for sound attenuation. Especially low end. Expensive acoustic foam can stop reflections and absorb highs, so while it makes a great last step for treating a room for mixing it is NOT where you would start if sound transmission were your highest priority.

Rigid fiberglass, however, totally smokes any foam, including high-dollar acoustic foam, when it comes to sound attenuation. The best is the stuff with the craft paper glued to one side. It's fairly cheap (compared to acoustic foam) but hard to find. You might be able to custom order it from a big-box home improvement store, but almost none stock it.

Regular R30 fiberglass rolls are not quite as effective as rigid fiberglass, but they still convincingly crush foams. I read one site which recommended buying the rolls and just stacking them, intact in the cellophane packaging, in the corners of one's studio as bass traps. Easy, cheap, and effective ($15/ea). I suppose if you didn't like the "ghetto" look of them, you could go to a fabric store and get some cheap muslin or burlap to cover them with.

Read up on fiberglass vs. acoustic foam (or any other type) with regard to sound absorption. Google it. Fiberglass and rock wool are way, way more effective.

Another side benefit: fiberglass and rock wool are fire resistant and do not give off deadly fumes when heated. Grab a piece of fiberglass insulation and touch a match to it. Anything happen? Bad smell? Now try that same test with a small piece of styrofoam (hint: better do this test outside with good ventilation! :) ).

amphog
01-29-2012, 12:34 PM
Heavy curtians will do more than rigid foam.

Scott Whigham
01-30-2012, 06:52 AM
Foam insulation of any kind pretty much sucks for sound attenuation. Especially low end. Yes, exactly. It wouldn't be a complete waste of money - your room would likely sound better to you and the band, so that would be good. But it wouldn't stop the bass/drums from bothering your neighbors.

Closed cell foam is expensive but I've found a good source here in Dallas through a nation-wide retailer. There's a company called SPI that has a good/decent price: http://spi-co.com/

They have a product called Armaflex Armacell that you can buy in 1" sheets for something like $30 for a 4'x3' sheet. Double those up (to make 2" sheets), glue together, and glue to a thin sheet of plywood to make a window plug. That should knock 30db or so. You can triple/quadruple for more if you want.

Crowder
01-30-2012, 10:28 AM
There is some great technical info at the Green Glue site.....many surprising facts about how sound waves travel and how to trap them. As noted above the bass freqs are the problem. Treble is easy to kill. Bass has got more fight in it. If you've ever stood outside a house where a band is practicing you will recall that what you heard was low-mids and bass.


http://www.greengluecompany.com/technicallibrary.php


:)

TDavis
01-30-2012, 10:54 AM
Foam insulation of any kind pretty much sucks for sound attenuation. Especially low end. Expensive acoustic foam can stop reflections and absorb highs, so while it makes a great last step for treating a room for mixing it is NOT where you would start if sound transmission were your highest priority.

Rigid fiberglass, however, totally smokes any foam, including high-dollar acoustic foam, when it comes to sound attenuation. The best is the stuff with the craft paper glued to one side. It's fairly cheap (compared to acoustic foam) but hard to find. You might be able to custom order it from a big-box home improvement store, but almost none stock it.

Regular R30 fiberglass rolls are not quite as effective as rigid fiberglass, but they still convincingly crush foams. I read one site which recommended buying the rolls and just stacking them, intact in the cellophane packaging, in the corners of one's studio as bass traps. Easy, cheap, and effective ($15/ea). I suppose if you didn't like the "ghetto" look of them, you could go to a fabric store and get some cheap muslin or burlap to cover them with.

Read up on fiberglass vs. acoustic foam (or any other type) with regard to sound absorption. Google it. Fiberglass and rock wool are way, way more effective.

Another side benefit: fiberglass and rock wool are fire resistant and do not give off deadly fumes when heated. Grab a piece of fiberglass insulation and touch a match to it. Anything happen? Bad smell? Now try that same test with a small piece of styrofoam (hint: better do this test outside with good ventilation! :) ).

+1...only make sure to wear the proper PPE, (respirator, safety glasses and long sleeves)...especially with rock wool!
Multiple layers if drywall helps in reduction of sound "transfer", as well as use of resilent channels to attach drywall to.

batsbrew
01-30-2012, 11:31 AM
only MASS deadens sound.

to do what you want to do, you have to build a thicker, heavier wall..
or build a wall INSIDE a wall. concrete block is best.


4" of rockwool in a nice frame, covered with a nice cloth, is the typical best 'cheap' way to help with sound transmission and taming frequencies inside of a room.

sink
01-30-2012, 08:10 PM
^ What he said. Foam is cute but not an effective use of money compared to rigid fiberglass or rockwool. Ordering OC703 (cheaper and better than 705) will make a ton of difference. They come in 2'x4' sheets; build a cheap frame, stack 2 in the frame, cover them in burlap, and you have a much more useful product that will reduce bass. Not sure where you are but if state side, sign up for the mailing list for JoAnne's Fabric; they send 40-50% off coupons regularly making the burlap purchase cost next to nothing. You can buy 703 or mineral wool at ATS Acoustics for the cheapest I've seen. Go to the DIY Materials section. I put 3 bass traps in a 10x10 room and could not believe the difference. I sold them to a friend who has a music room that is an acoustic nightmare; big difference.

TimSt.L
01-31-2012, 06:28 AM
We always used scrap rolls of carpet from a carpet outlet or store. They always have stuff that's too small to use for another job, or is out of style. And they'll almost always give it for free. We put a layer directly on the walls and ceiling, then hung another layer about 6 inches out from that and it has always worked wonderfully. We were a very loud metal band too. Half stacks and double bass.

Just a cheap option.

batsbrew
01-31-2012, 10:18 AM
rugs cut down high frequencies, but pretty much don't touch low end.

it's a simple concept, mass attenutates low frequencies.

sometimes, a little is enough.

sometimes, a lot still isn't enough.
all depends on your environment

acguitar84
02-26-2012, 07:32 PM
i've been installing some of the denim insulation made from recycled blue jeans. I'm using the R19 stuff. I don't have walls up yet, but just the insulation itself seems to be a nice sound stopper.

TimmyP
02-26-2012, 08:25 PM
http://www.owenscorningcommercial.com/docs/datasheet/Fiberglas700Series.pdf

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