Recently, my guitarist has been inquiring about getting a subwoofer, to add more "punch" to our sound. I had an idea, but I would like some educated opinions on whether it would work or not. We currently use two 1x18s and two 1x12s (they may even be 15s) with a horn as our PA speakers. The 18s are Peaveys and they are ported at the bottom. The port is a slot, approximately 2 inches high by nine or ten inches long. Would there be any benefit to reversing the speaker(s), so it fired into the enclosure rather than out of it, or leaving the speaker as is and putting a piece of plywood over the front of the enclosure, leaving the port uncovered?