Pioneer hu in network with rear fill questions

So I have a pioneer hu with network.  If I hook some rear speakers to it and run off of deck power, how exactly does it work? Is power cut to those speakers so there is no distortion at high volume? Does it automatically have them crossed so no low frequency goes to it, and is there any adjustments? I  have a set of FREE alpine 6.5 coaxials that I want to hook up like this for fun mainly just wondering if there was anything I need to know