Functions In The Audio Module (AUD)

The audio module (AUD) can run a number of different functions, but these functions can also be activated by other nodes. An example of these functions is lowering and increasing the volume. The signal comes from the infotainment control module (ICM), but it is the audio module (AUD) that actually changes the volume. The functions are described below.

1. Adjustable volume  , raises and lowers the volume
2. Adjustable bass  , raises and lowers the bass level
3. Adjustable treble  , raises and lowers the treble level
4. System generated sound signals  , assist other nodes in the system with single sound signals generated in the control module, for example alarm signals for the park assistance function.
5. Limiter  , the limiter function in the control module does not permit an increase in the power output level if this leads to a fall in sound quality
6. Mixing  , mixing allows numerous different sound types to be mixed. In this case, the different sound types are foreground noise, background noise and system generated sound signals. An example of this is where a CD is playing (background noise) and the carphone rings (foreground noise). The ringing signal will be heard through the loudspeakers while the volume of the music drops at the same time
7. Bass compensation  , the bass from the control module is compensated or modified depending on the volume level and the speed of the car. If the vehicle speed and volume level changes, the bass compensation is also changed
8. Treble compensation  , the treble in the control module is compensated or modified depending on how the volume is changed. If the volume changes, the treble compensation also changes
9. Equalizer setting, sound compensation  , there are different settings for the sound from the audio module (AUD). This compensates for factors such as the location of the loudspeakers and the layout of the car interior.
10. Dolby ProLogic II  , a surround decoder for sound reproduction.

There are two types of sound, foreground sound and background sound. The sounds which are foreground and background are listed below.

Foreground sound: 

• navigation
• system generated sound from the audio module (AUD) (different types of alarm sound)
• traffic messages.

Background sound: 

• analog radio, AM/FM
• CD player.

The functions in the different versions of the audio module (AUD) are:

High Performance 

1. adjustable volume
2. adjustable bass level
3. adjustable treble level
4. system generated sound signals
5. limiter.
6. mixing
7. bass compensation
8. treble compensation
9. equalizer.

Premium Sound 

1. adjustable volume
2. adjustable bass level
3. adjustable treble level
4. system generated sound signals
5. limiter.
6. mixing
7. bass compensation
8. treble compensation
9. equalizer.
10. DPL2 - Dolby ProLogic II.