Egg crate foam -how should it be used?

duanebro

I have a bunch of egg crate foam at work that was used for packaging. Guessing about 1.5" thick, 8x36". I know that people use this to line enclosures with. My question is how does it help and how much does it help? Would this work in the back of a overnight sensation?

Thanks!

Face

Unless a design specifically calls for it, I wouldn't bother with it.  Lining the walls with denim insulation is much more effective. 

isaeagle4031

Ive used it to line ported cabinets. It does help to reduce cabinet resonance some. Not as good as adequate bracing but still effective. For sealed, ive also used it in combination with denim or fiberglass. I cant say it always made a huge difference. 

jhollander

If it's the soft egg crate that you can push air through it can be effective adsorber for higher frequencies like 4K and up. There are so many better options.  I've only used it as a base layer.

Face

isaeagle4031 said:

Ive used it to line ported cabinets. It does help to reduce cabinet resonance some. Not as good as adequate bracing but still effective. For sealed, ive also used it in combination with denim or fiberglass. I cant say it always made a huge difference. 

Take a ported cabinet, line it with egg crate foam and speak into the driver cutout.  Then line it with denim or even PE's Sonic Barrier, both are a substantial improvement over foam, with denim being the better of the two.  Just don't stuff a sealed or ported cabinet with denim unless you're looking to kill some low end. 

Remember, we need to kill internal reflections that can allow sound to travel back through the cone.  I even line sealed cabinets with denim, then stuff with the appropriate amount of polyfill.

duanebro

Thanks. I looked at some tests on youtube and even put it over the speakers in my car. It didn't do much. I will just toss it.

Mzisserson

You can build a frame, how about 3? lets say 3" thick, 24x48 tall cover the front with a peice of plywood. 

Drill many 2" holes in it at random

Use two layers of that egg crate in the frame. 

Go to your prefferred fanric store and wrap them to match the decor in your room.

Hang two on the side walls at the second reflecrion point, and one centered over the hifi.

Sit back, enjoy both the new art, and enhanced fidelity. 

ani_101

The ply is in the front and the foam is behind the ply sandwiched between the walls? Should we use random diameters too for the holes?

I am going to make some panels, but was going to put ultratech denim over the ply base....

Face

ani_101 said:

The ply is in the front and the foam is behind the ply sandwiched between the walls? Should we use random diameters too for the holes?

I am going to make some panels, but was going to put ultratech denim over the ply base....

A ply frame around Ultratouch, with no backing would be more effective, especially if there's a gap between the Ultratouch and the wall.  Just take a look at how GIK Acoustics makes theirs: http://www.gikacoustics.com/

Mzisserson

ani_101 said:

The ply is in the front and the foam is behind the ply sandwiched between the walls? Should we use random diameters too for the holes?

I am going to make some panels, but was going to put ultratech denim over the ply base....

Basically it is like a thin box without a back. Yes, the foam is between the box and wall held in by the fabric wrap.

      Various fillers work better than others but a couple of layers of eggcrate are effective. Randomize the crap out of it. Different size holes work well, too, but there should be a lot of them so more of the wood is gone than is there.

      The idea is to act as both an absorber and diffuser. The best rooms I have been in seem to use a nice mix of diffusion and absorption, and the room is anything but completely dead. 

      They have been on my " to make" list for years... I have heard them twice in different rooms (Both just used 2" randomized holes) and they were quite effective. I think one used old mattress-topper, and the other egg-crate from a left over sound room job somewhere else. Too many other variables at play to notice which "sounded better", but when taken off the walls here was quiet a difference in both instances. 

PSchumacher

I use egg crate foam to cover up the mineral wool or fiberglass that really does the absorbing function.  The egg crate foam just keep the fibers under control.

kennyk

So, egg crate/mattress topper is out?

ani_101

Hmmm... I have been using mattress topper to line and ultratech to stuff... So what's the recipe?