2013 Soul+ Looking for Wiring Diagrams to install Aftermarket Sub/Amp-img_2854.jpg

Above is the factory amp in my car. On the side of the amp it says JBL 96370-2K600. I wanted to splice off the wires behind my head unit to use speaker level input to my new amp but I don't think there are any speaker wires coming out of my head-unit, only the factory amp. I got some wiring diagrams from my local Kia dealership but the amps on their diagrams don't match up with what I have in my car, only the 4 wires leading to my factory sub are listed correctly. It's the 4 wires left end of the yellow bracket which power the sub. White brown green orange. Those are listed in the Kia wiring diagram.

I could use a LoC off the factory sub's wires but I'm concerned that won't be a clean signal for my new amp and I don't want to amp a amped single.

Any help would be greatly appreciated!