2008 GMC Acadia Owner's 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. 3-125