I think that's correct. If you're going straight from the speaker wires into your amp without a LOC to convert from speaker/high to line/low, then you would use the high level inputs and let the Sony handle the conversion, functioning as a preamp and amp in one.So, I tried again, but this time I connected the amp to the Bluetooth mode, and I hear the sub, front speakers, and rear speakers, but I don’t hear the other speakers. Blue and grey are the rears. When I turn off the Bluetooth my amp doesn’t play, and I hear the other speakers.They’re not playing together, so I guess the amp is still not connected to the car. I think maybe I might have to try the high level inputs?