Hello,
I really like this site/forum! Lots of great information. I figured I would post up. I just started testing my high output subwoofer setup, so here are some pics. Each enclosure holds 6-15" and is powered by a Carver PM1.5 - Pretty concussive pressure wave. Super efficient, with output being solid at less than 12.5 watts output (only power on lights, and signal present). Full output -3db down from clipping 1398 watts per enclosure had the metal studs in the barrier wall moving 1/2 inch in and out. Ripple waves felt through 10" thick concrete slab.
Pretty happy with the results!