From the Owner's Manual: "o access the audio settings on the Pilot Panel, select > Audio. - Equalizer: Adjusts the bass, mid, and treble - Balance: Adjusts the sound level between the speakers - Volume: Adjusts the master volume, as well as the volume levels for the navigation system and phone" (emphasis added) You should be able to adjust navigation and phone volume here, independent of the master. The dashboard and steering wheel controls affect the master only, but settings allows you to crank up the nav relative to the other sources, for example.