Volume level problem with aftermarket headunit
So I had a REC nav system with the amplified factory stereo. I just installed a Pioneer AVH-X5500BHS using a PAC RP4-CH11 adapter. I'm getting some static noise across the radio when the volume is all the way down. I can only turn the radio up to about 6 on the volume setting (max is 50 i believe) before its too loud. I checked everything and it looks like its hooked up right but it seems to be outputting way too loud.
2014 Jeep Grand Cherokee Overland 5.7
1991 YJ SOA, Dana 44 rear, 4.56, locked front and rear, wagoner leaf stretch, 35s