Rear Seat Entertainment System (RSE), Generation 4.2 (2007-2008): Function: Headphones: Notes
The system includes two pairs of IR headphones as standard. Any number of headphones can be used as long as they are within range of the IR transmitter.
Sound is transferred from the screen to the wireless headphones via an infrared signal. There must be free travel between the transmitter in the bottom edge of the screen and the receivers on the side of the headphones. If the way is blocked, the signal may be interfered with and sound quality will thus deteriorate.
The headphones are switched on with the switch located on the side. The headphones switch off automatically if no IR signal is received for 3-4 minutes.
The headphones also have a button to set which audio channel to listen to. Channel A or B can be selected. Channel A is always transmitted from the left screen and channel B is always transmitted from the right screen.
Lowering the volume of the screen will increase the signal/noise ratio of the headphones. Optimal headphone output is obtained by setting screen volume to 75%. Headphone volume can then be regulated using the wheel on the headphones themselves.