Well the QRD is almost done. It just needs time to dry a little more and then to mount behind the screen on the front wall and support with some in-situ bracing. Might be a little tricky given it is 76" wide, 37" tall and weighs roughly 60lbs. Doh! Probably going to have to remove the left channel and center channel to do it without risking a calamity.

This project started as many of mine do. Useful junk (literally) falls into my lap. This stuff was packing dunnage for insulated wall panels. They are the types of panels used for the exterior of modern food processing plants, warehouses etc. These were in abundance and headed for the dumpster. My fater in law scored 23 of them for me, so naturally the wheels began turning on how to use them in the basement. Originally, we were going to use them as two flanking diffusers on the back wall on either side of the media shelf, but once I saw how rough it was going to turn out it made sense to use it behind the screen.

I found a program called QRDude a couple of years ago and started to read up and lust after building one of these monsters.

http://www.subwoofer-builder.com/qrdude.htm

I decided the best use of all the material was to build a single diffuser rather than several repeating periods together. It made for an interesting build.....

At first I planned out the build using the software and made a cheat sheet for use in the garage.



Then I got to work cutting down the blocks with a table saw. This soon became a horribly dangerous proposition, as the foam would chatter and eventually kicked back dragging my hand perilously close to the blade..... I almost pooped.

So, Olfa knife it was! I had to cut one side along a straight edge and flip it to finish the cut. It took an hour or so, but I had all my fingers in the end.

Here's were step 1 ended up. There were more interesting things in the works (the absorber panels) so it sat like this for a month or so.



Then I had to decide on a thin but sturdy material to act as the well dividers. It had to be cheap as well. This is a bonus round item and the funds for the theater are long spent...

I ended up choosing MDF wall paneling from HD and ripped them down to 9 11/16"- the max depth of the wells. Gluing them up was a couple step process. I only had enough clamps to do them in sections, so I split it up into 3 pieces and did one at a time. I had to use left over cut off pieces to shore the very deep wells up while the glue dried. 7 Tubes of PL Premium later... This was starting to become a not so cheap project.... lol.



Once the smaller sections were glued up and set for 24 hours I got set to glue them together onto 2 backing runners I will screw to the wall.



The next morning I test sprayed a small area with flat black spray paint. Not a good result. I guessed it would happen. Spray paint and styrofoam do not play nice together. It melts. I had a tin of water based flat black left over from painting the screen goal posts so away I went. A sprayer would'a been a lot quicker, but it was a nice lazy Saturday morning putter. We'll see what happens, but this monster might get installed tomorrow. Excited to see how it "sounds" or better yet, smooths out some mid to high frequency valleys it's supposed to do. We'll see. confused