The early prototypes were made from a single layer of 3/4 inch particle board. Little did I know at the time that these beauties would live in my living room for over 4 years. I originally braced the edges with a second strip of particle board about 2 inches wide. This was to flexible, and I ended up putting two full length 2 x 3's on the back. This helped a lot. Even without the vibration usually associated with a "Box" these baffles vibrate quite a bit.
These first two pictures show the early baffle. First with the Shiva and then with the two Dynaudios. The hole in the baffle was for the 12 inch Shiva had to be filled and then bridged over with another layer of particle board. The Dynaudios are about equivalent to a 9 inch driver.
This mess on the floor is all the temporary wiring, the two crossover boards, two Zen amps and a bunch of other stuff.
Here are a few detail shots of the framework that makes up the final baffle.
Bending those MDF half-rounds was a lot harder than I thought it would be. It seems like a gentle curve, but I had to confine the sides to keep them from spreading and make these special clamps to slowly pull the edges together.
Finally some finished parts! I now have a grill for the back and am experimenting with stuffing in the area behind the open drivers. I have used some felt on the edges and some Dacron fluff in the open areas.
I should say a little about the paint at this point. When I built the "El Nino" speakers a few years ago, I put a fantastic finish on them using Automotive lacquer and a whole lot of elbow grease. Many months later the MDF from which those speakers were made was shrinking and swelling with the changes in the weather and every seam and screw head telegraphed right through the finish. This was a little disappointing after all the work that went into them. In an attempt to prevent that from happening again, I decided to cover these speakers with a thin layer of fiberglass cloth and polyester resin. This seemed to make the surface much more stable and is holding up very nicely. The irony of this story, however, is that I never did get a good "piano" finish that I was trying for. I spent hundreds of dollars on paint and set up my temporary spray booth but every time I tried to spray the last coat of paint, something would go wrong and I would ruin the whole thing. The fact that it was December and in the low 30's and raining may have had something to do with it.
I finally gave up, got out a can of gloss black spray paint and misted the surface with this from about 18 inches away. This produced the nicest "pebbled" surface I have ever seen. I am very happy with this finish. It looks great, can be repaired if it gets damaged and doesn't show fingerprints. Sometimes you get lucky.
Here is a breadboard version of the electronic crossover.
Here is the original passive crossovers for the mid and tweeter. This is one mid crossover and one tweeter crossover.
Here are all four passive crossovers condensed and squeezed to fit in the very small recesses I build into the top and bottom of the baffle. That tweeter crossover on the left was a real tight fit in that little space above the tweeter.