bless those with little..
we started this topic with discussion on if it was worth bi-amping smaller boxes that have passive crossovers. I've done this myself and come to the conclusion, it rarely works unless the speakers are designed to allow this - then it does work. Some manufacturers use their own amps to drive their own speakers which is probably the best integration to ensure what comes out is what was intended to come out.
Bi amplification was/is awesome. You no longer used a subtractive tone control to adjust treble and bass. It was done through speaker balancing. The 10's ( and horn ) to the Hi's, and 15's to the lows. The signal never subtracted to drone up the bass this way. It works every time on my ADA bass stack with 10's and 15..
Cross-overs are great to split it up. The subwoofer always reproduces the basses better. So you cut the lows from the stereo monitors and X over in the subs. The monitors could handle the bass somewhat, its just the subwoofers are better at it.