Currently I'm running two X12D4s in a sealed "hatchback box", I plan to make two independant sub enclosures that will double as stands for my mains. I am running them in series off an old Stereo receiver (Genexxa is the brand

The sub system can get LOUD, I haven't ran it full, yet, since I live in a basement apartment below my LL.

I was planning on building some folded horns for the 12s, but after using the auto setup and it turning my sub down 5db and my mains up 4.5 db for a total differenc of 9.5 db, I don't think I need that efficiancy.

I'm actually trying to find a better amp, or pair of amps to use when I build the new enclosures, I'm thinking I may use one in box amp "module" and just run a wire from one to the other, kinda like the old Active and passive Bazoka tube set-up.
