[Box for 18" Xcon Help]

The port length given is for EACH port, so each port will need to be 36" long. Also, the volume seems to be a bit on the large side, might want to tone it down to 6.5-7ft^3 unless you're running less than rated power and need the efficiency via a larger chamber. The volume that you use in the port length calcs is the final volume after all sub and port displacements. Then you work backwards to find a suitable box size to give you that final volume after displacements.

Thank you for the help and I have 2 more questions,

How come when I use another port length calculator (the one above, http://www.mobileinf...20lenth%201.htm) the tuning frequency is different from the torres with the same height, widths and lengths & volume? the other one i have square and slot checked, and i have 3 common port walls on the torres & torres gives me a different frequency.

Do I need a double baffle for the box below?

This is what I've came up with

its 6.4 cubes @33hz after port and sub displacement.

[Box for 18" Xcon Help]

This is my first box build, & I want to build a box like the one below, and my questions are how do I calculate the ports lengths. dimensions are 14h x 33w x 35d

Do I use a port length calculator and just divide the length(36") in half for both ports & make each port wall 18 inches long & 5 inches wide?

[Come vote for my next potential sub :)]

ssa zcon