Thanks for the links and advice.

I did put a brace back under the table after the photo. I am going to remove the table and start putting in the new wiring next week.

The C-31 enclosure contains the D050 speaker system, two D-130 (b) and a DLH 175 driver. More pics in the photo gallery under home speaker systems.

I am placing the other one on the other side once the room is done. I know it is only a 15 ft wall but it is the only place I have.

Any suggestions on bracing the 24'' ceiling rafters?