Ok so ive decided to build a new box for my hx2s and need some help..... They are going in a 2002 eclipse and as it is now i have about the biggest box i can put in it....5cubic feet tunned to 35hz... They are 15s and dont seem to hit as hard as they should....Could it be because 15s need more room to develop than in the space of my car?....they are ran off a bd1500....Any one have any ideas?