This is probably a simple answer but i just dont know it. I want to build a box with subs and port facing back. The port will be app. 6in wide and in the middle of the box between the 2 subs. The question is when i l the port off to the 2 sides do i keep them both 6 in wide or half them to 3 in each? I wish i had a pic to explain but i dont yet.