Used the RE calculator and it is confusing me a little bit. It is saying 4.58ft^3 volume with 105 sq.in. of port but when i do the math I get the volume shown in the box (in the drawing)... Sayd the tuning is 42Hz~ which is exactly what I am looking for but I wanted to make sure everything is good since I am getting conflicting numbers on teh box volume...

Box is for a Mach5 SPL15