I was gonna make a box for Power Acoustik Fubr-12, port size is 4" x like 11.5", ill double check later...but thats for a round port. I was gonna make a slot-ported box, but how do the dimensions work out? I heard they sound alot different, cause of less port turbulance and such... I heard that you jsut keep the air space inside the port and the length the same...is that anywhere close?
If the surface area of the slot port is the same as the round, then the length will remain the same. For a 4" round, you'd need to build a square port 3.545 x 3.545, or a slot port with the equivalent surface area. The surface area of a 4" round port is 12.56 in^2 (surface area of the 4" round port is found by pi x diameter, or 12.56) You could make a slot port that is 12.56 high and 1" wide, etc.