46jimbo,
I don't know what kind of audiobooks you listen to, but I listen to a bunch of different music styles.
I installed the Honda Bass Speaker Kit into my Civic two weeks ago and I really enjoy the renewed sound coming from the OEM head unit. I really missed having really low lows that were part of more premium branded cars. Now, especially today, I was listen to Gustav Mahler and it was fantastic!!!
The upgrade is about $400.00. Or you could purchase the kit from Majestic Honda's website for about $300.00. I have the semi-complete installation of the bass kit on my website
www.abittans.com under automotive.