Hansom Sarwan

OK so i was going to sell my pair of Sundown Sa12s however i decided i would do a recone on both so it would be literally new again this is what i would like to know: -how much rms power can these Sa12 take to play them the best they can without causing damage to them daily Note: People have said 1500rms.-2500rms so i would like to know from you guys who would know best Also box design is key i would like to get a box design for these to play a little low but loud meaning to play from 32-55hz since most of the songs i would be playing is from 35-50hz and some hip hop would be lower but my purpose is for them to play loudly so i hope i can get help with a box design dimension i have to work with 39" width by 27" depth by 28" high i would like the box could be like 39" width by 20-22" depth by 20" or less height i currently have a orion 1200d on the subs and not quite impress so ive decide i would sell the amp and upgrade the amp All help would be greatly appreciated