speaker whine

Installed the m6pro plus 2k, was super happy with it... until i installed hertz speakers all round and jbl 5ch amp. There is feedback hum/whine through the speakers. This hum/whine was is not present if I connect the speakers to the headunit directly using the headunit built in amp. (ran this...

I apologize, but I am once again asking for assistance on this issue. I think I have tried everything I've been told. System Rundown: 2002 Saturn L200 •Electrical is a powder coated mechman 260 amp alternator, battery is a XS Power D3400. I have 0 gauge ofc big 3 •Stereo is a JVC KW-M780BT •...