I know this is very noob of me but I am really unsure and I don't want to fry equipment here. I was handed a Yamaha P7000s amp (4 ohm), two JBL JRX125 duel 15 inch speakers (4 ohm) and two Wharfedale EVPX12’s (8 ohm) for a gig. I would like to add the two Wharfedale EVPX12’s to the system (as...