That's all power, box, vehicle dependent. Well I hit a 139.8 with an old Kicker L7 10" in the same box that the 12 is goin in i just put a new piece of wood on the front of the box. Oh no, don't do that my man. Build a whole new box for the 12". It's well worth it. The 12" in the 10" box will probably sound like a 10" ^AGREE The box is 1.62 cu.ft. tuned to 35 hz and i was looking at the specs for the sa-12 it requires a 1 to 1.5 cu ft. box for SPL and after sub displacement it will be 1.5 It may sound find in the same box but tuning will change due to the difference in sub displacements. I have another box just sitting in my room waiting to put something in it's 3.49 cu ft. 1 6" precision port is goin in itim going to eventually probably put 2 SA-12s in it. but i wanna do one 12" in that smaller box for right now until I can get another amp.