Brief component description: Amplifier
WARNING: This page is about a different car, the 2013 BMW X5, 2012 BMW X5, and 2011 BMW X5. However, it is still accessible from the selected car via links, so may be relevant.
The amplifier has 4 input channels and 7 outputs.
The amplifier has a separate voltage supply. The amplifier is switched on by the RAD_ON signal from the ASK (> 8 V = ON/< 6 V = OFF).
On request from the headunit, the amplifier performs speed-dependent volume control. The low frequency range in particular is boosted at high driving speeds.