I have run into a few of these"no bass in the monitors" guys. They are worried about the monitors being blown by the low end. two solutions - 1- put in a limiter - that will stop excessive low end or 2- roll the low end off the bass at the board, like at 120hz or so. I tell the sound guys that I don't want the bottom in the monitors, just the low mids, to help me hear when I get away from the bass amp.