Hello everybody , I've never used areo ports before but I heard that they can sometimes be louder than rectangular ports. My box is in a jeep Cherokee and it's 19 cubes net before displacements. I want to have about 220 to 240 square inches of port and be tuned to 33 hz. Wat size areos would I need and how many, length, and were to buy. My subs are facing up and I want the ports facing up.