My frame (with sketchup file)

[danny.guitar]

I just got the wood/nails/materials from Home Depot today, all I need to get now is some insulation and fabric which I'll try and get tomorrow. One thing I failed to notice is that my frame is 2x4, but when measuring the oustide.

That makes it 1' 10" x 3' 10" on the inside. Is this not such a big deal since I can just cut the insulation to fit it into the frame?

Also, I attached the sketchup file I made of the frame I'm building.

Someone tell me if you see anything that I should change before putting it together.

Download SketchUp File (156 KB)

 

[notbradsohner]

Put the cross brace under the entire frame, instead of inside. If you are going to keep it on the inside, add two more bars parallel to the middle one at the top and bottom.

 

[danny.guitar]

Put the cross brace under the entire frame, instead of inside. If you are going to keep it on the inside, add two more bars parallel to the middle one at the top and bottom.

Ok, thanks.

That will leave a little bump on the back when I put the fabric over it, but who cares.

Also I decided to use mineral wool instead of 703 because it's easier to find and it's cheaper. These aren't going to be bass traps, just an alternative to recording into my closet (for isolation/deadening).

Should I use little wood blocks around the inside of the frame to hold the mineral wool in place? Like this guy did?

http://johnlsayers.com/phpBB2/viewtopic.php?t=4581&postdays=0&postorder=asc&start=0

 

[gullfo]

you can use 1x4 (3/4" x 3 1/2") for the framing - using 2 or 3 internal cross braces nailed/screwed and glued for the frame. insert the 4" insulation. cover with flame retardant fabric. add feet or hanging hooks as needed. you could use insulation strapping (a polyester type flat strap like what they wrap heavy boxes with - available at local building supply) to hold it in - along wih the fabric should be fine. if you want to lighten the frame, drill 1 1/2" holes spaced every 3" along the frame and cross bars.

 

[gullfo]

conversely, you could build out the braces as slats to add some low end absorption and high frequency reflection but at the cost of more weight. you could probably reduce the weight a bit by using 1/4" plywood and routing slats into that in 1/8"-3/4" widths. one side would be absorptive, one side more reflective.

 

[danny.guitar]

you can use 1x4 (3/4" x 3 1/2") for the framing - using 2 or 3 internal cross braces nailed/screwed and glued for the frame. insert the 4" insulation. cover with flame retardant fabric. add feet or hanging hooks as needed. you could use insulation strapping (a polyester type flat strap like what they wrap heavy boxes with - available at local building supply) to hold it in - along wih the fabric should be fine. if you want to lighten the frame, drill 1 1/2" holes spaced every 3" along the frame and cross bars.

Thanks gullfo.

My original plan was like the one in your first picture (the one on the left), so maybe I'll add a couple more boards on the top and bottom of the frame to hold the insulation in.

I'm not real concerned with weight. I thought they would be a lot heavier at first because I was going to use 2x4s

I may just get some burlap to cover the frame and then some flame retardant spray to spray on it.

Right now I'm trying to get as much absorption with as little reflection as possible. I'm trying to deaden an area of my room for recording.

Before, I was recording into my closet and using clothes to absorb the sound, and it worked well. But that's a pain in the ass so I thought setting up a few absorbers behind the mic would work the same, or possibly better.

 

[gullfo]

i was thinking about weight in case you wanted to hang one overhead... with the 2x4 construction what you can do is add some 1/4" plywood triangles into each corner to square it up and then cover with cloth. with the 2x4 you can also use the hole-saw trick to lighten it... may even increase absorption and diffusion somewhat. depending on which way you might want to squeeze in the insulation, it will determine if the length is shorter than 4' or width less than 2'. or if you have the limber make it so it fits...

 

[studiomaster]

I got a dumb question...since you're building 2' x 4' panels...does the wood sizes have to be exactly 24 inch by 48 inch as well?

 

[scrubs]

I got a dumb question...since you're building 2' x 4' panels...does the wood sizes have to be exactly 24 inch by 48 inch as well?

The insulation comes in 24"x48" sheets, so it is easiest to have the internal dimensions of the frame be 24"x48". However, it is possible to trim the insulation (a drywall saw works well for this) if your panels are not exact.

 

[gullfo]

if you have the lumber to make the interior 2'x4' it would be easy. but if you have space limitations on the size of the entire absorber, you may need to trim it or if it is soft enough to "squeeze" it a bit to make it fit.

 

[VSpaceBoy]

Well a little small is no prob at all. Just stuff the rockwool in there, it'll fit. Thats what I did.

Also, the 2x4 contruction with the rockwool is going to be heavier than you'd think. I thought you were going with the 1x4's?

 

[pdlstl]

(a drywall saw works well for this)

A $10 electric carving knife from Walmart works much, much better.

Presuming you're talking rigid fiberglass...

 

[studiomaster]

How thick does the wood pieces have to be? Is 1" wood pieces enough for this?

 

[VSpaceBoy]

Yes