ok here is my problem, im going to build this type of enclosure for a truck with a shell and a walk through (no back wall). i need to save as much side to side so what i was thinking was instead of building 4 identical boxes (all on end with horns forward horizontally) could'nt i just build one box wide enough for 4 woofers ( 8 total) so the plan would still be a 36"x36"x49.5"  this is just the same a s one box but wide enough for the 4 woofers. it would save me alot of would and about 4 inches or so on space? please help if you can. i am very experienced with enclosure building but this will be a totally new design for me.
forgive the crappy paint pic but hopefully you get the idea

If each speaker is fed the same signal, what difference would it make if the airspace were summed rather than seperate as long as its the same volume?

John C.