[Bad70sbchevy]

Thanks airspeed, im definitely going to run that program once i get a rough design of the box. Right now I already got the 12" subs from a friend of mine and I was just tryin to see if I could fit them in my truck. I would of bought shallow subs if it wasnt for that. I'mk startin to lean on tryin to fit the subs behind the seat since I already got 6x9s and a 200W amp under the seat. I think I might be able to fit them in the rear corners of the cab. Just in case that doesnt work, I was thinkin about down firing them in the cab, what kind of difference will I see sound wise versus mounting them regularly?