<< just make sure ur box is the right size >>
Well, there really is no "right size."
There are trade offs between power handling, efficiency, extensition etc... which are affected by the size and type of enclosure.
I prefer no box.
My trunk is sealed from the car, so no rear wave cancellation of the front wave. Due to the size of the trunk, my subs perform as though the box was of infinate size, which for subs is esentially anythign larger than 4 times the vas.
