help with box specs plz

[brent379]

ok so i decided to mess around with torres's box tuning calculator and so i can start designing the box for my soon to be aa havoc 18

idk how to copy the actual screen onto here so here are the specs:

OUTER DIMENSIONS:

H- 21.5

W- 33.5

D- 28.5........ equals 10 cubic ft internal box volume...

PORT DIMENSIONS:

10X10X25......TUNES THE BOX TO 31.98HZ....WE WILL SAY 32HZ

gives me 12.63 square inches of port area per cubic foot....

sub displacement is .22....so ill have 7.9 OR 8 cubes after displacements...

heres my questions....using the calculator when your messing with the dimensions of the port i put in 25 inches as the length....on the far right side where the calculator gives you all the specs it says phyisical port length is 14.25"...which length do u go by??

and also...is 12.63 square inches of port area per cubic foot enough??? that doesnt sound like enough....should i go bigger??

i would like to do an interchangeable port. so i dont want to use one of the walls of the box as part of the port. i basically want to completely build the box...build a seperate port and cut a hole somewhere on the box and stick the port in it. i want to do this so i can do different length ports to see about what frequency i like the best.

and also im gonna have the sub firing upwards...so which way would be the best way to have the port facing??