Mixed subs in separate boxes?

[clutch1]

I've got 2 12'' Visonik subs in a dualbandpass box right now. My friend may be getting rid of his system which has 4 MTX Thunder4500 12'' subs. I'm thinking about buying it. What I'm wondering about is if I was able to fit maybe 2 smaller boxes along with my visoniks in my trunk will it sound ok? I'd probably have 2 sealed single 12" boxes along with a big bandpass dual 12" box. I'm really more interested in loudness and not bass for things like rock, since I only listen to the subs with rap and such.

Or would the 2 different sub/box types mix soundwaves and sound like shit?