Mercedes-Benz C-Class 2009 COMAND Manual - Manual (Page 151)

Audio Aux
149
G Warning
Due to the different volumes of the external
audio sources, system messages (e.g.
navigation announcements) may be much
louder. You may need to disable these
system messages or adjust the volume of
these messages manually.
i The volume of external audio sources is
extremely variable. It is possible that a
device connected as an external audio
source will sound quieter or louder in the
vehicle or that the usual maximum volume
cannot be achieved. On certain devices the
volume can be set separately. In this case,
start at a moderate volume and increase it
slowly. In this way, you can determine
whether the system is capable of playback
without distortion, even at high volume.
Audio
Z