ok built my enclosure,

40w x 15d x 10h external dimensions w/ 3/4 mdf

port is

10h x 4w x 21l

im getting different answers on cu ft, what did i end up with when all is said and done ?

ive been out of this for so long i feel like an idiot with all the questions, but you guys are a really great help. THANK YOU

Edited June 10, 200916 yr by wrldzmyn

I dont see how your getting 10 for the port height, thats not possible.

However if the inner dimension is 8.5h of the port.

Then it looks like your at 1.73cuft@41Hz

(not good for a daily setup)

^thats with speaker and port displacement included.

I came up with 1.983 cubic feet after speaker and port displacement.

Edited June 10, 200916 yr by OldSkool_08

my bad, its 40w x 15d x 12h with a 10 x 4 x 21 in port

I get 2.5 Cubic Feet tuned to 39Hz

What changes to the port need to be made to make this enclosure go from 39 down to 32Hz. I am about to build a box.

port needs to be a little longer around 35 inches

Edited June 11, 200916 yr by wrldzmyn

40 sq in of port area? Isn't that a bit much for a single 12? Should be more like 24-32 sq in. I'd try decreasing your port area then your port length will be much shorter for a 32hz tune, more like 24in.