i have i box that i need to find out what it's volume is and what it is tuned at. it is made of 3/4" mdf and has a double baffle. outside dimensions are: H 23 1/4" W 20" D 45" inside port dimensions are: H 5" W 18 1/2" D this i am not sure which measurement i need if i measure from the face of the port to the back wall it is 44 1/4" deep if i am to measure the length of the wall which divides the box to form the port it is 38 3/4" deep there is a 45% in the back of the port. thanks in advance for the help. would like to learn how to do these calculations also. perhaps if some one had the extra time i would love to see it drafted up into a drawing also , that would be to cool. my hopes are to identify what i have in order to see what subs would be good in this box. then make another to match it and put both side by side in the jeep. sub up, port back. http://i151.photobucket.com/albums/s149/porkchop22_2007/box1.jpg