GMC 2008 Acadia - Manual (Page 267)

Rear Seat Audio (RSA)
This feature allows rear seat passengers to listen to and
control any of the music sources: radio, CDs, DVDs,
or other auxiliary sources. However, the rear seat
passengers can only control the music sources the front
seat passengers are not listening to (except on some
radios where dual control is allowed). For example, rear
seat passengers can control a CD and listen to it through
the headphones, while the driver listens to the radio
through the front speakers. The rear seat passengers
have control of the volume for each set of headphones.
You can operate the RSA functions even when the
main radio is off. The front audio system will display
the headphone icon when the RSA is on, and will
disappear from the display when it is off.
Audio can be heard through wired headphones
(not included) plugged into the jacks on the RSA.
If your vehicle has this feature, audio can also be
heard on Channel 2 of the wireless headphones.
The audio system mutes the rear speakers when the
RSA audio is active through the headphones.
To listen to an iPod or portable audio device through
the RSA, attach the iPod or portable audio device to
the front auxiliary input (if available), located on the
front audio system. Turn the iPod on, then choose the
front auxiliary input with the RSA SRCE button.
P (Power): Press this button to turn the RSA on or off.
Volume: Turn the knob to increase or to decrease
the volume of the wired headphones. The left knob
controls the left headphones and the right knob controls
the right headphones.
SRCE (Source): Press this button to switch between
the radio (AM/FM), XM™ (if equipped), CD, and if
your vehicle has these features, DVD, front auxiliary,
and rear auxiliary.
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