That actualy didn't answer my question. I'm not asking about airspace or power ratings. I'm asking about cancellation by having some subs face forward and some face up. I would fire everything forward, but the box dimensions will not allow that. So, if I fire the port and 3 subs forward I will get as close to all forward as I can get, then I would have one subs facing up. Right now the port is firing to the side, with only about 4 inches of space.
So, will having subs face more then one direction in the same box cause any problems? Otherwise my only option might be subs up and port forward.