memory foam for sound panels?

[swellis01]

Anyone try this?
I'm building a drum/tracking room in my basement and plan on creating some
4" thick, 2 foot wide by 4 feet tall panels to hang on the walls to reduce reflections. I was thinking of framing out the panels with 1X4s and using memory foam on the inside as a sound absorbsion material. I could back it with metal screening, and cover the whole thing with nice looking micro-fibre fabric.
Anyone know of any benefits to using visco memory foam as a sound proofing material?
Thanks, Steve.

87, how's your "Rivers Of Wine" CD? I still have that song in my head!

[87PRS]

hey Steve, good to see you here, been awhile. Actually did a whole new studio re-take on Rivers of Wine, and...the original that you remixed for me from 1/4" tape is "framed" and hanging in my studio, played it some and put it up for posterities sake. Good job.

I've never tried the memory foam you are speaking of, could be a good material for absorption. I've got a drum room, its 12X16 and the main bummer is I only have 8' ceilings in there, and I do have a 40X40" viewing window. I'm using Aurelex for absorption, and some panels at 45 degree angles where walls and ceilings meet, bass absortion blocks in corners, and actually have a heavy material behind drums at cymbal height framed in wood its about 3 X 7'. Last fall I built the drum riser in there its 5 X 7 braced 2 X 4's filled with sand and covered with a 1" 4x8 composite board cut to size, its really deadened the riser, but then I have a wood floor built on framing not concrete. I'm getting ready to put wood slat flooring in live room, week after next. Keep us posted on your project! Ralph

[swellis01]

Thanks for the Kudos Ralph, it's funny to think that CD is hanging on a wall. Was the redo with new musicians/insruments? Or did you go for another remix?
I've actually been elswhere in the forums, mainly helping "Roddles" with a new PC build in the "PC OS and Hardware" section. long thread!

I found quite a deal on this visco memory foam in an Ebay Store. It's being sold as a 3" (or 4") thick, 6.5Lb, mattress cover. I would be cutting it up for my purposes, however. It's a pretty dense material, more so than auralex and others. Which, IMHO is WAY too overpriced. What a racket! I used to work in and airplane interior shop and we had all kinds of foam all over the place, throwing out large chunks all the time!

Anyway, I can't seem to find any info about the use of this kind of foam for sound absorbtion purposes. So the question still remains....anyone? I think I'll just get it and see what happens.
see ya 87,
Steve

[Audiodude]

Originally Posted by swellis01

Anyone try this?
I'm building a drum/tracking room in my basement and plan on creating some
4" thick, 2 foot wide by 4 feet tall panels to hang on the walls to reduce reflections. I was thinking of framing out the panels with 1X4s and using memory foam on the inside as a sound absorbsion material. I could back it with metal screening, and cover the whole thing with nice looking micro-fibre fabric.
Anyone know of any benefits to using visco memory foam as a sound proofing material?

I don't know of any benefits, but I'd caution against using any product for acoustic absorption that hasn't been designed and tested for that purpose. I can't imagine that memory foam has anything close to an even frequency response, and a quick Google search didn't turn up any NRC specifications.

Also, microfiber (or any tight-weave fabric) is generally not recommended for acoustic treatment. You'll want something that is acoustically "transparent."

May I ask why want to use memory foam in particular? There are lots of alternatives that I would think would be cheaper and more effective.

[swellis01]

I guess I don't have a technically accurate answer. It seems dense. Its fun to play with. It seems, anyway, like it would work pretty well as a sound absorbing material. I can get it cheap. Those are my only answers. I am open to other suggestions.

Is the problem with a "tight weave" fabric the idea that it would reflect too much sound to make the absorption material useful? Certainly Micro-fiber is thin enough to let almost all the sound to pass through. The difference between that and say, a tweed fabric would, I'm sure, be negligible. It's a little more expensive but looks real nice.

[Audiodude]

Well, I can't argue there. It's fun to play with. But since acoustical data doesn't seem to exist for it, I wouldn't put the stuff up in my studio. If you are looking to save money with a do-it-yourself solution, I'd suggest using panels of Owens Corning 705 mineral fiber insulation covered with fabric. It's significantly less expensive than the pre-fabricated foam panels you mentioned.

Foam products not designed for acoustical application typically have very uneven frequency responses, and can make your room sound very muddy. This is the problem with the classic "egg crate" foam that so many do-it-yourselfers use for acoustic absorption.

Regarding fabric - The rule of thumb I've heard is that if you can't feel a puff of air through the fabric, it's too dense to be useful to cover acoustic panels. Another test is to cover the tweeters of your studio monitors with the fabric, if the sound changes, you know some of the energy is being reflected.

[87PRS]

Originally Posted by Audiodude

Well, I can't argue there. It's fun to play with. But since acoustical data doesn't seem to exist for it, I wouldn't put the stuff up in my studio. If you are looking to save money with a do-it-yourself solution, I'd suggest using panels of Owens Corning 705 mineral fiber insulation covered with fabric. It's significantly less expensive than the pre-fabricated foam panels you mentioned.

Foam products not designed for acoustical application typically have very uneven frequency responses, and can make your room sound very muddy. This is the problem with the classic "egg crate" foam that so many do-it-yourselfers use for acoustic absorption.

Regarding fabric - The rule of thumb I've heard is that if you can't feel a puff of air through the fabric, it's too dense to be useful to cover acoustic panels. Another test is to cover the tweeters of your studio monitors with the fabric, if the sound changes, you know some of the energy is being reflected.

The Owens Corning 705 insulation is good stuff, I made up some panels from Ethan Winers designs on his forum, they work jamm up, also built the bass panels with 705 incased in them, my 20X16 live room sounds good for being so small. Check out Ethans designs.

The best fabric I found is verging on a silk feel, light and not alot of density, easy roven fabric I can see alot of light. but in the case of using 705 Keeps the fiber particles down, which is important.

Steve we re-done the entire song, new musicians, same instrument line-up, new tracks etal, came out alot better than the original 1970 version LOL. Now...why wouldn't I frame something that can never be replaced...its right by my Gold Record Ha Ha

[swellis01]

Thanks for the suggestions guys, I'm convinced. I still might experiment, but the 705 does seem like a better, and more predictable, solution. Plus, I think I remember seeing it at Lowes. I'll go that route for the actual panels. Gotta checkout that fabric Ralph. Where did you purchase it?

[87PRS]

Well Steve I made a mistake....gulp...
It was johnlsayers sight I got the traps from...
http://www.johnlsayers.com/phpBB2/viewtopic.php?t=4581
http://www.johnlsayers.com/HR/index1.htm.

and here are the absortion co-effiect values for some materials, very helpful
http://www.bobgolds.com/AbsorptionCoefficients.htm

I used a burlap material (for looks) with a silky type backing cloth (to keep the dust in), available from Wallyworld, buy the burlap and silky stuff seperate. I used caulk and layed in silky stuff, then cauled again layed in burlap, then caulked again and screwed wood strips on it.

[terry]

swellis01

I think I remember seeing it at Lowes.

Ive looked all over Minneapolis could not find the stuff. But now there in town I think Ill give them a shot. Do you remember how much they ran?

[Audiodude]

Most home improvement mega-stores don't carry it. You can find a dealer on the Owens Corning website. From what I've been able to gather, they sell for between $1.50 and $2.00 per square foot for the paper-faced 2" 705 panels. Here in Fort Wayne, IN, they are only available from one place - an insulation contractor name d Momper Insulation

For the thrifty, Fibrex mineral fiber panels are also reportedly very good, at around half the price of OC 705. Rigid mineral fiber panels are also available through Sweetwater for about $2.00 per square foot in 48 sf quantities (although I suspect you might find them cheaper at an insulation contractor).

I've attached Owens Corning's spec sheet for their 700-series products, which shows full acoustical data:

[sabianq]

hi,
i would like to comment.
the memory foam that was spoken of in the front of this tread is actually a flexible polyurethane material called a Viscoelastic.

what makes these materials unique is the fact that they exhibit both viscous and elastic characteristics when undergoing plastic deformations. it is categorized as Non-Newtonian fluid. the more energy you subject it to the harder it resists the shear force.
there has been a great amount of speculation as to the acoustic properties of this type of material, idealiy, and in theory, you could produce a material that could reflect different frequencies like a pass filter.

this material would also in theory make a fantastic bass trap.

my guest room in my house which doubles as my studio room has a bed with a viscoelastic mattress by Tempurpedic and the bass response with the bed in the room is quite flat.


but in general, the properties of the material make it hard to hang on the wall as the force of gravity has a tendancy to deform the material over time.

[swellis01]

Geez everyone, awesome responses. Thanks too all. I just put up my last drywall panel and am getting the project's dust all over my keyboard. Great internet leads Jeff and Ralph! This forum has always been the best. I'll check all these out right after I get the dust off my hands!
I also just picked up a Line 6 Spider III combo amp, 75, for studio use and a friend is coming over to play it. (me is drummer. no can play geetar) Interesting thoughts on the viscoelastic foam. Again, I may just experiment with it.
see ya,
Steve

[sabianq]

I would experiment with it.
I bet it would work great.
I would suggest that you build a frame with slots built in to it that would hold the foam to keep it from sagging. build squares into the frame like a grid, maybe make them 3 inches deep and 2 inches on each side (assuming your mattress is 2 inches thick.
then cut the foam into "cubes" each with a different length and stick the foam cubes in the grid.

or

in essence you would have a resonator/diffuser hybrid.

this in theory should be able to control the low, frequencies as well as the high end frequencies too.

if you cut the foam to a length corresponding to a prime root relationship to the other pieces like 1, 3, 5, 7, etc..

or you can cut them in a Quadratic relationship

just dont make them to long so that they droop from hanging on the wall..


check this out for information relating to the math of diffusion.
http://en.wikipedia.org/wiki/Diffusion_(acoustics)

[sabianq]

you cant have innovation without experimentation