Check my sig for current setup. Should I keep my 2 12's or get something new? I want to keep the box below 4.5 cu ft (my current box is 4.5 and I don't know how I got it to fit). I have been doing some research and it seems that DD subs can handle my modded MMATS D300HC amp without a problem. Whatever I end up getting needs to be at a final load of 2-ohms. Should I get 2 DD 3512s or 1 DD 9015? Or, should I just keep my HCCA 12s? I want to achieve more SPL.