bass traps with styrofoam and fiberglass?

[CarloBadalamenti]

After reading your post, I'm not quite exactly sure what you intend to create with your design, in regard to where the styrofoam is used in your build. Is there any way you could post a diagram or sketch of your idea? With that said, I'm not sure where styrofoam would produce any benefit in a bass trap build. People are right in that it won't "stop sound" but it isn't acoustically transparent either. It's going to reflect, which is kind of the opposite of a bass trap's goal. Again, a sketch or diagram would definitely help as I may be completely misinterpreting your idea, but styrofoam is going to be reflective in any scenario.

EDIT: Oh, where are you located? Reason being, materials vary in availability and price region to region and somebody might be able to help you by pointing out something that's both attainable and affordable in your area.

[Glenn Kuras]

I am not sure either what he is trying to do but you could use it for a frame. If you put it on the face of the panel it would reflect the upper frequencies but hard to say how much and at what frequency. I honestly would not do it as there is to many unknowns.

[CarloBadalamenti]

Originally Posted by Glenn Kuras

I am not sure either what he is trying to do but you could use it for a frame. If you put it on the face of the panel it would reflect the upper frequencies but hard to say how much and at what frequency. I honestly would not do it as there is to many unknowns.

The framing was where my line of thinking was going as well; using the foam structurally could potentially be doable and affordable depending on how it's sourced. But for performance, there have got to be some better alternatives than styrofoam in your area, particularly for a panel's facing. Using it would be a shot in the dark more than anything.

[groovecake]

Thanks for the response guys. My train of thought was since one once compared on this very forum I believe "styrofoam in trying to stop sound as glass trying to stop sunlight" i was under the impression sound went right through So I was considering the option of having that completely on one side of the frame then the other smaller sytrofoam cut size of inside the frame to fit it and everything sealed inside like fiberglass I could pressure as much to be denser in there you know. But yeah I was thinking sound would go just right though it wasn't thinking about reflections there. Maybe I can just use some thin wood or cork type material for the front. I dont know. I see in youtube and forums and just have a panel of fiberglass or rock wool, build a frame and cover it with some cloth. Here It cant be that simple :(. What else could I do. The thing is keeping the fiberglass with some pressure so it not just there doing nothing an actually works as a bass trap. Maybe some foam on front. Then seal the insides, fill with fiberglass and cover with styrofoam to make it as tight as possible in there. I don't know what to do. Help guys! thank so much for the responses so far.

Now i know its a bad idea to have the styrofoam on outer layer since it would reflect sound and not let it be absorbed. What could I use as a top layer? that would still give me the option to come on the back with some wood or styrofoam and push in to make it at least a little dense and Would my styrofoam idea I have work as a cloud if I covered it with some diffusers? Then it would absorb and diffuse.
Thanks for taking time to read guys. some sketches of my original idea coming up to make it visual.

[CarloBadalamenti]

Ah, okay, that’s how the Styrofoam would have come into play. Unfortunately I think the person who stated Styrofoam is to sound what glass is to light, may have meant it in terms of trying to use it in a “soundproofing” construction build which requires a few special techniques and strategies, as opposed to using it for sound treatment.

Word or cork for the front of the panel would produce the same reflection problem as the Styrofoam – you need something like a taut acoustic fabric that lets the sound pass through into the interior fiberglass, like you said you’ve seen elsewhere. If you put the Styrofoam on the outside surface of a cloud, it isn’t going to allow any absorption to take place behind it, only reflection. To get diffusion you would have to have the Styrofoam patterned to scatter the reflections all over, with the pattern depths and rises designed formulaically.

As far as the problems you’re having with the fiberglass density and packing it in there, a few others around here have more expertise in that build area than I do, so hopefully they can offer a few pointers that can help you figure out how to make what you have work.

[AwwDeOhh]

I would skip trying to pack/compress the insulation.
If you leave the insulation loose and fluffy, but make the trap much deeper than 'normal' (say a foot or more deep), it will be much more effective than using the rigid stuff. Cover with fabric, done.

[groovecake]

Thanks for that last comments! You made my week exciting with the new project I'm going to start. Thanks! Anyone else got any more recommendations?

[DanDan]

Best DIY Trap EVER

DD