Building The Enclosure

I chose to design and construct my own enclosure this time. Since I could not find the proper round edge pieces, I made the prototype box without them. (Edge Difffraction be damned!) 

The Materials

Not being able to find MDF locally, I used 3/4" inch particle board. These sheets come in 4x8 and are generally available because they are used in underlayment. To make construction simpler I used simple butt joints. I was willing to spend the sanding time required to make nice smooth edges in this fashion. In order to get the large 4x8 sheet home, the kind people at builder's square were nice enough to cut it into four 2x4 foot sections. This is perfect since it takes only one 2x4 foot piece to make the speaker (minus bracing).

The Construction

I began by laying out the required cuts. Six side panels and two braces are needed per speaker. The two sides panels need to be 17" by 10.5", the front/rear panels are 17" by 10", and the top panels measure 12" by 10". To assemble, all of the side/front panels are sandwiched between the top and bottom panels. I used number 6-1.5" wood screws and joined the edged with liquid nails before assembling. 
Then came the sanding. Since I was without a power sander and the funds with which to purchase one, it was a long difficult job. After two days of my arms continual ache (about 4 hours of actual work), they were ready for finishing.

The Finish(or how not to enamel)

This was a learning experience. First, do not use any water based enamel, paint, or lacquer with particle board. I had the unfortunate pleasure of using an acrylic gloss enamel. This warped and roughened the once smooth surface and the first box ended up with a rough exterior.  Here is the final developed two step finish process for a black gloss laminate style finish...
1.) Apply two or three coats of sandable primer to the surface. After the final coat dries, lightly sand the surface.
2.) Apply two or three coats of the gloss enamel. If applying by brush, make sure the brush is saturated before application and you make very light coats. Heavy coats or an unsaturated brush could cause air bubbles within the coat.
In the end you will have a highly resistant black gloss finish. It should look smooth and clean. If it reflects uneven, you have not yet covered the particle board properly.