I'm replacing the stock sub in my vehicle with a JL Audio 8w1v2, and will power it with a JL amp. My enclosure (fabbed to fit the vehicle, already made) is .6 cu. ft. The sub calls for .375. I'm limited on mounting depth, so this is the best I can do as for the sub. Is there a way to effectively reduce the enclosure (sealed) volume, or should I just leave it be?