Size of box would be the issue with it bottoming out. 1 12 should be in roughly 2-2.25 cubes ported, tune it to around 35-38 hertz. That q will still drop decently low at that tuning and you'll still have punch and your higher end. As for port stick between 12 and 18 square inches of port per cube. sub up port up on the driver side. Or sub forward port up on driver side. Brace the heck out of it as well as the port, this is the reason quite a few ported enclosures sound like a$$, because they are flexing. If you do the 2 12" ssd's stick around 4 cubes subs forward or up and port up driver side. same 12-18 square per cube (shoot for around 14) and brace the heck out of it. I prefer to make as wide of a port openning as I can and still get the tuning and everything that I"m looking for. Never built an enclosure that didn't suprise me using these rules of thumb.