Spec wise the JBL should sound more powerful. Note though the impedance rating is just over 2 ohm (normal speakers usually at 4 ohm) so you may need a separate power amp that can handle continuous (stable) 2 ohm load. If you just hook them up to your existing stock system, the speakers might overload and fry your system. So if you just want to plug it into your existing system the Sony should be the safer choice but again sec wise/theoretically it might not sound as powerful as the JBL (note the lower sensitivity rating on the Sony is just 88db compared to the JBL at 92db, plus the Sony cone size is slightly smaller too by a quarter of an inch).