Spoke to a local Audio Geek about adding an amp and changing my tweeters. He asked me if my model had ALL of the power (including to the sub) coming from the head unit or if it had an external amp. I know the E and Black models have an external amp but not sure about mine. I have the 8" touch screen. is the power on this unit all in the head unit? Also, what type of power is my unit giving to each speaker? 15 Watts? 25? D