"The Excite Sound system integrates with the car's standard Composition Media System, but can also be specified with the optional Discover/Discover Pro navigation systems.
As for audio, the Dynaudio set-up includes nine speakers around the cabin, a dedicated subwoofer and 400W digital amplifier. The dual two-way systems (one each in the front and rear pasenger compartments) each comprise a pair of Dynaudio soft-dome tweeters and two 16.8cm MSP mid/bass drivers."
Taken from the above link.