Figuring port length on the12volt.com help

[afrakes]

Got out and measured my mostly assembled box, I have 4.25 cubes gross. When I use the port length calculator on the12volt do I use this gross measurement? Or do I need to readjust/guess and check to figure the best i can my net airspace???

[ShadeTreeMechanic]

Somehow you will need to account for woofer and port volume. This is why some people invert their subs and have ports sticking out of the box.

[afrakes]

Ok so basically cat and mouse it until the math is as close as possible. .2 for woofer, .8ish for port. Damn. My box just got small.

[ShadeTreeMechanic]

Yeah I had to measure my truck a few times in order to make sure it wasn't going to be too big to fit. Don't get stuck on a magic number for box volume. They say that a difference in size of up to 10% won't make a noticeable difference. Also a port along a wall is effectively 1/2 port width longer because some of the wall outside of the port belongs to the port. A port that ends in the corner even more so.