stereo questions?

the box or encloser the sub (s) are in makes a big difference to...

Yep most subwoofers comes with a spec sheet that tells you what cubic inch range the sub box needs to be in order it achieve the best performance.

NOTE: I'm by no means a no it all... just what I've read on car audio forums and other car audio type information. When I built my system in my truck I studied and read before I bought the materials to build the boxes, amps, etc...