i currently have 2-15in L7's powered by a zx2500.
yesterday i heard a solo x 18 and i was blown away. it was definitely louder. the enclosure is a poorly ghetto rigged constructed box and was only 4.5cuft (below the minimum vented enclosure specs) and he had 2 power acoustik a3000db's strapped to it. it impressed me cuz if i get a 18" then its goin to be powered by (2) zx2500's in a net 6cuft enclosure so it should actually sound awhole lot better and louder.

so this is how the setup will be if i were to go with the 2-12's or 1-18

3cuft each


so which would be louder? i have a dodge charger.