V50 L5-2.4L VIN 39 B5244S7 (2005)
The audio module (AUD) is an amplifier which is connected to the MOST network. It has the following functions:
to carry the sound signal transmitted on the MOST network out to the directly connected loudspeakers
to carry voice messages from the microphone, which is directly connected to the audio module (AUD), to the MOST network.
If a subwoofer module (SUB) is installed on the MOST network, the audio module (AUD) can process the incoming signal and transmit it to the
subwoofer module (SUB).
There are three versions of the audio module (AUD):
Performance (included after structure week 2004w46 in the Integrated Audio Module (IAM)). Has an output of 25W per audio channel. The
control module has 4 audio channels, these produce a combined output of 100W.
High Performance. Has an output of 40 W per channel. The control module has 4 channels, giving a total output of 160W
Premium Sound (not C70). Has an output of 70W per channel plus an output of 25 W for the channel for the centrally-mounted speaker. The
control module has four channels plus the channel for the centrally-mounted speaker. This gives a total output of 305W.
Premium Sound (C70). Has an output of 130 W per channel. The control module has 5 channels, giving a total output of 650W.
Each version of the audio module (AUD) has a different number of loudspeakers and different loudspeaker models.
All versions of the audio module (AUD) have a microphone input. This is used by the phone module (PHM) for phone calls (handsfree) for example.
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.
Functions in the audio module (AUD):
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, assists other nodes in the system with single sound signals generated in the control module, for example alarm
signals for the back-up (reverse) warning 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. Digital bass speaker output, the control module transmits sound signals to the bass speakers via the MOST network. The signal is processed in
the audio module (AUD) before it is transmitted on the MOST network to the subwoofer module (SUB)
8. 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
9. 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
10. 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
11. 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.
carphone settings (setting the ring signal)
system generated sound from the audio module (AUD) (different types of alarm sound)