Design

Design

Control module




The Audio module (AUD) is an amplifier that transports the audible signal, transmitted on the MOST network, out to the directly connected loudspeakers.
If there is a subwoofer module (SUB) installed on the MOST network, the audio module (AUD) can process the incoming signal and transmit it to the subwoofer module (SUB).

The following versions of Audio module (AUD) are available:
- High Performance
- Premium Sound
Audio module (AUD) High Performance has 4x40 W output and Premium Sound has 5x130 W.
Each version of the audio module (AUD) has a different number of loudspeakers and different loudspeaker models.

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. Digital bass loudspeaker output, via MOST network, transmits signals to Subwoofer module (SUB). No foreground noise must be included in the signals.
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.

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

Background sound:
- analogue radio, AM/FM
- CD player
- playing sound via the AUX input.
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. digital bass speaker output
8. bass compensation
9. treble compensation
10. equalizer

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

Loudspeakers




High Performance
For High Performance 8 loudspeakers are used. It is a 2 way loudspeaker system with base/mid-range and separate tweeters. The speakers are installed in the front and rear doors. In C30 and C70 the rear loudspeakers are installed in the side panel.
The impedance is 2 ohms for the base/mid-range loudspeakers and 8 ohms for the treble speakers.
Premium Sound
For Premium Sound 9 loudspeakers are used. It is a 2 way loudspeaker system with base/mid-range and separate tweeters. The speakers are installed in the front and rear doors. In C30 and C70 the rear loudspeakers are installed in the side panel. To increase the sound there is a 2 way central loudspeaker in the dashboard.
The impedance is 4 ohms for the base/mid-range loudspeakers and 8 ohms for the trebles. The center loudspeaker impedance is 6 ohms if a display screen is installed in the dashboard, otherwise the central loudspeaker impedance is 8 ohms.

Microphone

Applies to -2009





Applies to 2010-




The microphone is directly connected to the audio module (AUD). The microphone transmits analog signals to the control module.
Telephone calls can either be connected via the handsfree or secrecy headset. Calls made via handsfree use the microphone and speaker connected to the audio module (AUD).
The microphone is phantom fed via the audio module (AUD).
For further information, see Design and Function, phone module (PHM).
For further information, see Design and Function, Bluetooth phone module (BPM).