I don't think you will have a problem with your situation. With the speakers located in the area of 8' high ceiling, bass will reflect from the ceiling so it would contribute in the room just as would the floor reflections. If you placed the speakers at the other end of the room, you might experience less reflection in the bass region.

Furthermore, I would not worry too much about bass below about 200 Hz or so as it will trend toward omnidirectional in a normal sized room because of sidewall reflections. Your line arrays will continue to sound nice in this area as you'll have some directional clues versus bass from a single woofer/subwoofer. Yet with the lines you'll have good dispersion via these 'stereo' bass sources that should reduce room mode effects.

Jim