end correction on external port

[dmz2711]

I want to build a small wall in a hatchback for either 2 12's or 15's. The problem i have is i am working with a limited amount of space.

I wanted to do the two subs on the bottom and a square port on the top along the roof. I got to thinking what if i went with an external square port, that way i don't have to apply port displacement within the enclosure, giving me a little more room. The question that is buggin the :ranting2: out of me, is if i go ahead and do an external port, do i still need to factor in end correction considering that the roof of the vehicle is going to be the top part of the port?

I've read JL audio's site about end correction and they say "remember, the driver can't "see" the length of the port, it can only go by what it "feels" is going on." Seeing that info from the site i think i should factor in end correction even though it is an external port since one piece of the port(the roof) goes on further than the actual port. But, I really have no clue, and need help from some of you experienced peoples. thanks

[David]

draw me a picture or take a pic, depending on how it sits  you might have to factor it in.

[dmz2711]

draw me a picture or take a pic, depending on how it sits  you might have to factor it in.

here ya go, thanks for takin a look. right now it would just be a concept, just trying to see if it is even possible. I am really unsure of the end correction though.