The presence of suitable inputs. I would imagine the specifics would differ from one brand to the next but as far as my Polk/Momos are concerned on the input side of the passive crossover modules there is a switch for either Dual input (bi-amping) or Single input (standard amping)
Additionally there are separate inputs for midwoofer and tweeter amplifier channels if the Dual input option is chosen.
For these Polks if you aren't going to bi-amp them (using the Single input option) you'll only use the inputs marked as 'Tweeter.'
I'm not familiar with Hypnotic's gear in the least so if there is a bi-amp option on them I wouldn't have the 1st clue as to how to go about it.