Hey y’all! I drive a 23 IS350, and have always had the complaint that the bass in the standard premium sound system was very lackluster. I am planning to install a JL audio subwoofer soon to help resolve my issue. For anyone who’s installed a sub on their IS, did you also upgrade the amplifier? If you didn’t, was the subwoofer enough to help enhance the sound stage / listening experience? Any helpful information would be greatly appreciated!

Also, how many watts total is the 10-speaker premium system?

If you want real bass, you'll be need a separate amp... Depends on your musical taste and budget!

Did you replace the factory speakers or did you just install subs and a separate amplifier? Which one did you go with?