I'm active with the 80prs and I hooked up my rear door speakers to the head unit, and the speakers are very very quite, any ideas were I went wrong, I can't imagine there that quite because there not amped.
If you look at the installation manual, the network mode makes the front outputs the middle range speakers, and the rear outputs are the high range speakers. If you want to run rear speakers you should operate the head unit in standard mode, not network mode.
The head unit doesn't have enough channels to run tweeters and mids active, rear speakers, and a subwoofer. Proper rear fill needs to be delayed and it should not be playing the same information as any of the front speakers. To keep this an active system with rear fill you need an 8-channel DSP.
Even if you don't care about the best rear fill your options without buying an 8-channel DSP are not great. You could use RCA Y-splitters with another amplifier, and then you would have the choice of playing the front low channels through the rear speakers with plenty of power. This is going to mess up your sound all around, but hey, some people say it's all about what you want to hear.