started building my box

well i posted here a few days ago about building a box for my 9500 and i started it yesterday.....but i am wandering, i am going to flush mount the sub so i will be putting another identical piece of wood over the front of teh box.....i will just cut the opening bigger to make it flush....now when i do this it will extend my port another inch....can i just take an inch off the beginning of the port inside the box to make up for the inch on the end....sorry if that is hard to understand.....if you guys need to i can draw a picture....thanks for the help

If you wish to keep the port the same size, then yes, cut some off the back. New Project: 2003 Pathfinder

ok thanks