how do you configure the calculation

i am trying to learn how to understand the calculations of sub enclosures i have been building sealed boxes just off of general knowledge and now i wanna start doing things the right way such as i  have a 2000 tahoe z71 and i want to build a box for it that will hold 8 10" ma audio subs model ma100xe but dont know what would be better ported box or fiberglass. how do you convert the volumes of the sub    here is some pics of my work this is one of the center consoles for a tahoe

 this one was built to hold a ten inch flat screen and 2 6.5 stype speakers

 thanks alot       ram customs