Full-Cabin Upgrades are wonderfully musical sound systems, using stock locations.
“Four-way” Full-Cabin systems include a true trunk subwoofer, and use
the underseat woofers as dedicated midbass drivers.
Add-A-Sub packages for E92 add a high-performance 12-inch subwoofer in our OE-Look Enclosure.
Add-A-Sub packages for the E93 upgrade the underseat 8″ woofers. Both add dedicated amplifiers.
Full-Bass Upgrades add a high-performance 12-inch trunk subwoofer and a multichannel amplifier,
and improve midbass performance. Not available for E93.