Ready to DIY acoustic panels, now have a question

[anderson0196]

Ok - Thanks to a lot of help from the board members here, I'm about to build some 4'x2'x4" panels. Here are my materials:

- OC 703 (2" thick so I'll be glueing two together)
- Some plywood that's been ripped 4.5" wide
- Fabric to cover them

All in I've spent about $160 and have materials to build 6 of the panels - pretty good I think...

I'm thinking that it would be wise to glue the fiberglass to a sheet of cardboard or something similar to provide a little additional rigidity to the panels.

My question is whether this is a good or bad idea - Will it impact the panel's effectiveness?

 

[bpape]

You don't want to put anything on the back unless the panels will be hanging flat on the wall. The plywood frames will flex but if you have them already, then I'd recommend just doing a 1/2" thick brace across the 2' dimension in the rear and screwed in from both sides. That will stiffen it plenty to allow you to stretch the cloth tightly.

Bryan

 

[anderson0196]

Thanks for the info Bryan.

The plywood is 3/4" thick - Do you think the bracing is really necessary? If so, can you provide me with a better idea of what you're suggesting?

The panels will be hung on the wall, 3 behind the L/C/R speakers and 3 at first reflection points on the rear wall.

I had the plywood ripped to 4.5" so that there would be a little room left by the 4" thick 703 for mounting hardware and anything else I might need back there, so there would be approx. 0.5" of "space" between the 703 and the wall if I don't put a backing on it - Will this be helpful from an acoustics perspective?

The 703 is still packages so I don't know exactly how rigid is is - Are you saying it's rigid enough that no addt'l backing is necessary?

Thanks again - Jim

 

[rolyasm]

Would love to see some pictures of this process. Where are you getting the specs and ideas from?
Roly

 

[Jack Hammer]

The bracing referred to is a simple cross member. Picture a rectangle, that is your frames basic shape. If you draw a line down the middle widthwise you have two squares coming to gether to form that rectangle. That is how you would brace it. Hope this helps:
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If you search the forums for diy acoustic panels or home made acoustic panels you should get several threads about members who made their own panels. Along with pictures and what worked/didn't work from experiments.

Jack

 

[ParadigmDawg]

703 is pretty darn rigid and will not require any type of "backing" that will only reduce what you are trying to accomplish.

 

[chas_w]

Here's a pic of the cross brace on one of my diy's:

http://swbg1.tripod.com/panel_1.jpg

 

[anderson0196]

Thanks guys.

Chas - What are the holes in your frame there for?

 

[chas_w]

Chas - What are the holes in your frame there for?

Just trying to open up the sides for additional absorbtion:

 

[bpape]

The 703 itself needs no bracing. I was suggesting it purely from the standpoint of keeping the frame from flexing in when you try to stretch cloth over it tightly.

Bryan