The new enclosures for this design are more complicated than any I've yet built. Each speaker utilizes two separate enclosures, like the originals, but in this case they are actually separated from each other. The upper MTM cabinet is simply a vented bookshelf speaker that is separated from the lower cabinet by using two 3" diameter PVC tubes that are 1-1/2" long and bolted through the center. I thought I would go all out and try to time-align everything, so the woofers use a 1-1/2" baffle, where as the tweeter is set back 3/4"

My main goal in this new design was to measure the woofers I had, and build the perfect-sized enclosure for them. In this case, it was about 2.1 cu. ft. after subtracting driver displacement. An 11" long 3" diameter port would yield an F3 of about 37 Hz.

This was originally going to be a typical rectangular prism with double-thick walls, until I remembered a design that Zaph had used for a couple of wall-mount Aura speakers he built. He used a wood bending technique that I thought was very cool and not too difficult to try, so I drew a curved-wall design in AutoCAD. The curved-wall version looks better, and also helps to make the cabinet stronger-doublethick walls are no longer required. The top and bottom plates would be double-thick however, and there's also extensive internal bracing. The finished result is a woofer cabinet that weighs close to 50 lbs. empty, and has almost no wall resonance.