I finally got the two 10 x 6" TLA's finished and installed in my son's grade school auditorium. I made the mounting brackets from 2" square steel tube cut into "U" shaped pieces and bolted together. Each mating pair have a 10mm tapped hole, the nut on the inside is a locknut. This geometry allows for both pitch and yaw adjustment. 12 x 14# x 2" screws hold each bracket to the 10mm plywood panelling, that's barely 2 lb per screw! The cab's weigh about 25 kg or just over 50 lbs apiece, and are quite solid. The only give is in the wall panels. What do they sound like? Clear, crisp and direct, a huge improvement over the cheap Selenium 12" + large piezo wedges that were up on the wall previously. With a few dB of boost in the 40-60 Hz region, and all the way down cut below that, the sound has sufficient bottom end to satisfy the needs of the school. They are connected to a 500w per side amp, one side to each speaker. I cranked it up to the point where the timber floor was thumping, still crisp and clear! The school principal was very impressed, the near field effect is quite noticeable, the sound level anywhere in the audience area sounds much the same, which is how they were designed to perform. I have yet to hear them in a full auditorium, but some who have already have noticed the very big improvement.
