Stereo/hi-fi 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.
Hi-fi amplifiers are amplifiers with active frequency diplexers. Active frequency diplexers achieve better acoustic results than passive frequency diplexers.
The hi-fi amplifier does not have speed-dependent volume adjustment or speed-dependent equalizing. The function of the hi-fi amplifier is only to amplify the low-frequency output.