circles are the most efficient shape in the universe. that's why when you blow a bubble with soap water the bubbles try to shape in to a sphere. Planets, stars, moons, volcanos, etc.... are all spherical. when was the last time you saw a square volcano opening?
it's because of the amount of surface area presented per ratio of port area. There will be a ton more air dragging against port if you had a super skinny port of say... 16" tall and 1" wide than there would be in a 4" by 4" square port.
Yeah I'm prettt sure it has to do with the air resistance on the port walls. My buddy has a ranger with 2 15s and we saw a nice gain going from a long skinny port accross the whole box, to a box with a wide mouth port.
amplifier, amp guts, ampguts, car audio classifieds, speakers and subs for sale with listings of 12 volt sound systems. Security systems for sale for aftermarket car audio equipment with amplifier and amps for sale