I was thinking i could fit the SA 12s if i cut holes in the box and did the fiberglass "bubble" over the woofer vent cause i only have 7.5" of outside box height so after i subtract for wood im really at 6" of internal space. But if the SD 12s will sound just as good, according to win isd they aren't much less than the SA 12s if i modled them correctly that is lol. they also save me some cash to put towards other things so i thing unless i find something better ill go with 2 sd12 D4 wired to 1ohm.