Grant, good info, I realize your post is old but maybe you can answer a question. I have a 2009 911 Turbo with the Bose system which in my mind sounded good. I recently had installed a new head unit for a bigger screen and car play, Pioneer Avic-W8500NEX unit. Nice unit. However, I think it's not as loud and crisp as the old factory head unit. Brought it back to the installer, played around with the 13 ch equalizer, helped some. But with different types of music I need to change the equalizer which is a pain going from song to song. The amp under the passenger seat seems to be working as it gets hot. Did pay for the adapter to use the amp and steering wheel controls. Installer is now saying I need to put new speakers and amp in to get louder sound and more crisp sound at the tune of over $3000! Anyone have any advice or insight on this? Thank You!!