That is how you figure out the area of a circle (Pi*radius^2). For a 6'' aero you would get around 28 square inches of port. But I messed around with a 3'' aero for my 10'' BL and got a lot of port noise on the lower frequencies....so maybe sticking with a regular slot port would be better. What about subs up and port to the side?
i think i am actually going to go with an aero port, but i'm confused on what i need to order, it doesn't tell me how long the 6" piece is...
nevermind i don't know what i want to do...lol