They'll definitely suck up midrange/high reflections. I use them in my control room as sidewall absorbtion when I mix to reduce/eliminate early reflections. Moving pads are another option.

Safety is an issue.

The professional foam is fire retardent. There there was a major tragedy involving innappropriate foam in a club several years ago.

Eh I'm not so much really worried about anything catching fire, but if the stuff works I'll get it. Is there anything else thats cheap and good to use ? Please post. :) :)

Unless you live alone in a house that is detached from your neighbors, fire safety is not just your worry. I think all bedding material has to be rated for fire safety, so you can look up the specs on the foam you are looking at.

The best cheap per square foot stuff that I know of is rigid fiber glass like Owens Corning 703 and 705. Not quite as easily available or as easy to work with as some other things but it's good, cheap, and safe.

Sponge! That's right, sponge. Sponges...they aren't just for dishes anymore.

Hit your local dollar stores and buy up every damn package of sponges that they have. Pick up some glue while your there too.

Open all the bags of sponges into a pile in the center of the garage. Give everyone in the band a bottle of glue and then start tiling the sponges on the walls.

The yellow sponge is very common and great at absorbing requencies in the 8-10k range. Blue sponges are excellent for the upper-mid requencies. Green sponges (although hard to find) are superb absorbers of high requencies from 12-20k.

If you can find them, the sponges with the scrubber pads on one side are great. Glue them with the scrubber side out. The scrubber will "scrub" out the low requencies and the high requencies will pass through to be absorbed by the spongy part. They are a great dual purpose sound absorption device.

Happy recording and happy thanksgiving.

Tongue-in-Cheek Productions

Sponges!! Wow that never even crossed my mind. But so far so good, thanks for the ideas!

I forgot...

Sponges tend to dry out and get hard. This decreases their absorbtion capabilities. The good thing is that when this happens, you just spritz them with a little water and they are good as new.

There's a little known secret in the sponge absorbtion community. It's called waterlogging. Many 'spongers' will apply large amounts of water to the sponges, waterlogging them. What this does is increase the requency aborbtion range of the sponge...downward. For example a yellow sponges requency aborbtion range would increase from 8-10k to 4-10k. It's great if you can only get one color of sponge.

Sponges tend to dry out and get hard. This decreases their absorbtion capabilities. The good thing is that when this happens, you just spritz them with a little water and they are good as new.

What about mold formation from the moisture???

pr0gr4m wrote: --Sponges--

Haha. It's hilarious until you make this poor guy go out and spend lots of dough, pr0gr4m.

I knew a guy who thought that dollar store sponges were too expensive too. He took a trip to Australia to go diving on the Great Barrier Reef and gather his own sponges. It's a well known fact that the natural sponge increases a rooms dynamic range by 10-13db.

jonyoung wrote: What about mold formation from the moisture???

You would think that mold would be a common problem seeing as how there are sponges filled with water glued to the walls...and it is. But there are some cheap and easy things that can be done to combat the mold with very little sacrifice to the requency absorption of the sponges.

Tilex is a great way to kill and prevent mold in the sponges. That's right plain old regular Tilex, or the dollar store equivalent. It can easily neutralize and get rid of any mold in the sponges. It can also help to prevent new mold from growing if used regularly. Most people will simply mix bleach and water in a sprayer which can do the same thing at a much cheaper cost. If this is the way you want to go, a cup of bleach for each gallon of water should do the trick.

The only drawback to using Tilex or bleach is that it discolors the sponges which reduces the sponges requency absorbtion. If you are concerned about mold, but don't want to ruin your room acoustics, there is a product out there that can stop the mold without ruining the sponge, sodium bicarbonate powder. It's not hard to get but it can be expensive. It's the chemical used in many dry chemical fire extinguisher. Not only can it put out fires, it can stop mold in it's tracks and prevent it from coming back for up to 2 months. The only problem is that dry chemical extinguishers are much more expensive than a bottle of bleach. Also, it can be a pain to apply. You have to either empty out the room or cover everything up so that it's air tight to keep the dust from getting in the equipment. So most 'spongers' will use the bleach and learn to live with the recuency change of their room over time.

Happy Recording

Tongue-in-Cheek Productions

No sponge-treated room would truly be asthetically complete without an assortment of the following strategically placed throughout the room. The overall effect will amaze and amuse your clients. These are especially great in corners:

http://www.plushfriends.com/spongebob.html

Kapt.Krunch :roll:

The only drawback to using Tilex or bleach is that it discolors the sponges which reduces the sponges requency absorbtion

There is another drawback.....bleach stinks. I don't think my lungs would approve of sitting in a bleach fumed room all day. I'm sticking with the mattress pads. I only use them in the control room, no smoking policy in place and a fire extinguisher right next to me.

pr0gr4m wrote: I knew a guy who thought that dollar store sponges were too expensive too. He took a trip to Australia to go diving on the Great Barrier Reef and gather his own sponges.

:lol:

Hope he picked up some corals too. Awesome diffusers. Ocean way acoustic treatment pack.

jonyoung wrote:

The only drawback to using Tilex or bleach is that it discolors the sponges which reduces the sponges requency absorbtion

There is another drawback.....bleach stinks. I don't think my lungs would approve of sitting in a bleach fumed room all day. I'm sticking with the mattress pads. I only use them in the control room, no smoking policy in place and a fire extinguisher right next to me.

I'll second that, mattress foam sounds the best.

Maybe this is baseless but one would think that matress companies would insure that their foam pads are fire retardent since people plan on sleeping on them. Just a thought. I don't know how that affects their usefulness or lack of in regards to sound absorbtion.

Acoustic foam versus glass wool (fiberglass) panels

There is much misinformation in the market regarding acoustic panels. Please allow me to clarify some bits. First and foremost, if it can be made to vibrate, it will absorb sound energy. When sound penetrates the membranes in foam or the minute strands in glass wool, they vibrate and convert sound energy into heat. The science is known as thermodynamics. The absorption coefficient or ability of a product to absorb energy is rated using a simple scale with 1 being 100% at a given frequency - and 0.8 being 80%. As a general rule, the thicker the absorber, the lower the frequency. This is why bass traps are bigger. You can estimate the absorption of a given panel using quarter wavelength calculations, but this is very inaccurate. The only way to accurately measure the performance of an absorber is to place a number of these it inside a test chamber such as the ones employed by Riverbank Labs and run tests. Unless you can get a copy of the actual independent tests, do not believe what you are reading. Anyone can buy convoluted mattress foam and put it up for sale on a web site.

The absorption coefficient is also related to the density of the material. Higher density materials will absorb more bass while low density materials only absorb high frequencies. High frequency absorption is easily done with foam or even carpet. However, this causes a worse problem whereby the room will be bass heavy. So when you mix and listen back on another system, you will find that your mixes will likely sound harsh in order to compensate for the uneven response. Acoustic foam is typically cut from blocks of 1 lb per square foot foam buns. These are shaped in a zigzag to look pretty and give the impression that sound is being diffused. This is not the case. Foam is too soft to diffuse energy. Because half the foam is being cut away, you are only getting half the density - thus much less low frequency performance. Vocal booths are often plagued with a problem that is known as chest hump. This is caused by two factors: the first, since the size of the room is often 4'x4'x7' high, the room will have resonant frequencies at 157Hz and 275Hz (bumps or standing waves). Second, because the low density foam will do absolutely nothing to absorb energy below 500Hz, it will sound dead in the high end. You will end up with a muffled yet pronounced low end response that sounds awful. A viable fix is to add tri-corner traps up high in the corners.

Higher density materials such as 6lb per square foot glass wool will absorb low frequencies down to 100Hz, depending on the thickness. It is available from Owens-Corning for do it your-selfers or pre-made from companies like Primacoustic. These panels absorb audio frequencies more evenly - and can be compared to a microphone or speaker that produces a flat response. In a studio, you want your room be ne neutral. This is the type of material that professional studios employ. You hang it up on the wall like a picture. No more messy glue to contend with during installation or drywall to repair and clean up when you move.

There are a few other things to consider which got me onto this thread. The first is dusting: Foam like any plastic is affected by ultra violet rays and oxidisation. So over time, the foam will change and begin to dust. The foam itself may or may not be harmful to your health, but the fire retardant that is embedded is listed as a carcinogenic. Don't eat your foam! On the other hand, glass wool was recently removed from the list of potential hazards by the American Cancer Society. Glass is considered to be inert. But this does not mean care should not be taken when handling it. If you intend to cut and build your own glass wool panels, wear a long sleeve shirt, gloves a mask to avoid inhaling the minute fibers. At Primacoustic, each panel is surfaced with micromesh and the edges are resin treated to harden them so that the fibers are fully encapsulated. If making your own panels, you may consider doing the same. This eliminates dusting.

The second concern is fire: We all heard about the fire in the New-England night club that was caused by pyro-techniques and acoustic foam. Foam - even when treated - is not fire safe. The treatment inside the foam will only slow the onset of a fire, giving you more time to escape. This is why foam is not approved for use in construction anywhere in America or anywhere else in the world. This is particularly important for those living in apartments or high density residential areas. You can certainly use whatever you want in your home as you are your own master, but only class-A rated materials should be used in public or commercial spaces. This will not only work better, you will not be held liable if a fire happens to break out and your studio foam is blamed for being a transmitter. The owners of the night club were charge a $1million in fines and they went to jail for several years. Considering a starter London 8 acoustic kit with proper panels only costs about $250 - this seems to me as a better and safer route to go.

Peter Janis - Primacoustic

What ever happened with Sonex? Is the stuff still made? That stuff over time deteriorates into a mess.

rmburrow, post: 447037, member: 46233 wrote: What ever happened with Sonex? Is the stuff still made? That stuff over time deteriorates into a mess.

Before I knew much about all this wonderful pro audio/ acoustic stuff, I bought 20 Sonex 2 x 4 foam sheets for my first home studio. They must be 25 years old now and still look and feel like the day I bought them. I use them around the shop to reduce reflections plus they add a visual studio cool factor. People comment on them all the time.
(I use them instead of pictures on the walls). They work very well for what they are.

audiokid, post: 447041, member: 1 wrote: Before I knew much about all this wonderful pro audio/ acoustic stuff, I bought 20 Sonex 2 x 4 foam sheets for my first home studio. They must be 25 years old now and still look and feel like the day I bought them. I use them around the shop to reduce reflections plus they add a visual studio cool factor. People comment on them all the time.
(I use them instead of pictures on the walls). They work very well for what they are.

I put Sonex up in a radio station studio when it first came out to cut down reflections and noise from outside the studio..The stuff worked but over time the material gradually degraded into a powdery mess...and was eventually replaced...

audiokid, post: 447041, member: 1 wrote: Before I knew much about all this wonderful pro audio/ acoustic stuff, I bought 20 Sonex 2 x 4 foam sheets for my first home studio. They must be 25 years old now and still look and feel like the day I bought them. I use them around the shop to reduce reflections plus they add a visual studio cool factor. People comment on them all the time.
(I use them instead of pictures on the walls). They work very well for what they are.

I like the way they look, personally.

For the OP, I've seen a couple places using moving blankets. It's also something a lot of people have. I have no idea on fire safety for that though, or the egg crate foam. Fire retardant materials can make the difference between losing some stuff, and losing everything. Some people think it would be better just to lose everything and have insurance replace it, and start over. A friend of mine lost his house, his entire house. And it was absolutely devastating for them. They were in motels and friends houses for 2 years while it got rebuilt/replaced. 2 years! And insurance doesn't make it easy to replace stuff. They want receipts or pics (with model numbers etc). There are a ton of questions from insurance fraud investigators. I had a car burn to a crisp and even the hassle for that, felt endless.

You can check the ratings for the egg crate or moving blankets, maybe they are fine. Or maybe you are ok with the risk...

My point is, you don't want to mess with a fire. It's an awful ordeal, so, whatever you decide, be safe bud.