i'm guessing by power you are referring to loudness?
if so both, but sound quality is more important to me than loudness
yeah, i know bigger boxes help the sound, i have a hsu-vtf15 sub for my home theater and that box is HUGE:P
i know those subs have a recommended box to them but that is too big for my trunk
for amp - i want something that is powerful enough to supply power to the subs for full power but not draw too much power from my alternator/battery (do I have to be worried about this, i'm not extremely car knowledgeable).
like i said early, my vehicle is a 2012 fusion, so i dont know if some amps are to physically big for it either, once i get an enclosure case for the subs
(I do need to maintain a trunk to haul groceries and such in, i'm not planning to lose the trunk).
let me know which amp you think I should buy. Cost is really no issue (i have no problems paying up to $700 online if you tell me it will get me better performance/not drain my car's "main" power)