BTW, the reason why most people take the factory HU out of the equation is that it's got some filters and EQ in it that you can't remove, which effects the sound quality once you move into some higher-end equipment. I kept the stock HU and ran high-level inputs to my DSP/Amp, but I really only use the stock HU for news radio every once in a while. Other than that, I use my DAP. The difference in sound quality is night and day.