Update: To follow up on the posts I made a while back with my plans for DIY acoustic paneIs, figured that I would explain where I am at this point.
I finally found the time to try to put together one absorber panel and found out some interesting points with regard to the physical construction that surprised me.
The OC703 is heavier than I expected and the 1/4 plywood was more flexible than I counted on. As a result, when trying to move the 2' wide 8' long assembly, it flexed all over the place and made it difficult for the spray adhesive I used to attach the OC703 to the plywood to maintain its grip.
This is a photo of the plywood (with 3 large areas cut out) with the ripped down 2-bys attached to the back.
I ended up ripping down some additional 2-by-4s to about 1 1/2" to place between the horizontal pieces to give the unit some structural rigidity and yet leave the sides partly open.
I attached plastic drywall corner bead to all the edges so there would be a clean edge all the way around for the fabric covering.
The photo below is taken while the unit was still on the work table (face down).
I have placed the unit in the theater, but have not had the time to evaluate its impact on the sound in the room. Our room has a curved back wall with a short radius, so I know the room needs serious treatment, but I don't have the knowledge to approach it very scientifically.
I have actually come to the conclusion that some of the professionals are scared away by the shape of our room, as I have e-mailed and called a few who have never gotten back to me...(and I was not asking for free services)!
With regard to the post suggesting using fabric on the back and perhaps door stops as stand offs, if I understand the suggestion correctly, I think that the weight of the OC703 would make that unfeasible. Please correct me if I am wrong - I am all for easier-cheaper-lighter!!