Aftermarket Sub With Factory JBL System

I have an 08 Double Cab Tacomo with the factory JBL audio system. I just receintly replaced the HU with the Pioneer AVIC-Z1. I had to use an LOC in order to retain the factory JBL speakers and amp. I now want to install aftermarket subs and an amplifier. Is this possible? Can I just plug the aftermarket amp into the AVIC-Z1 and control it from there? I figure I still have to use the factory amp for the door speakers. Do the door speakers turn off if the factory sub is not used? Any help would be greatly appreciated.

 

That should all work out fine. Check out my for sale page. Selling some subs and amp too. http://www.tacomaworld.com/forum/bu...nt-rear-bumper-trd-coils-jl-amp-tow-hook.html