Answer
The question often comes up among users of K.2, KW, KLA, and CP Series active loudspeakers: How can I run a passive loudspeaker off my active loudspeaker?
The answer is you cannot; each QSC active loudspeaker has amplification, processing, and protection specifically designed for the loudspeaker drivers used in that model. There is no way to use it to drive an additional passive loudspeaker.
Each QSC active loudspeaker model has a line-level output from an onboard mixer that sums the various inputs. You can use this output to drive the input of an external power amp, which in turn drives one or more passive loudspeakers.