GF82.60-P-2003TM Volume/Tone Adjustments, Function

GF82.60-P-2003TM Volume/Tone Adjustments, Function
- with CODE (523) MB Audio 20 radio
- with CODE (510) Audio 20 with CD changer


Function requirements:
^ Status "Circuit 30 ON" or "Circuit 15R ON"
^ Radio (A2) is authorized and operating properly
^ Audio source in operation

General information
All volume and tone settings are performed using the radio. This is accomplished either by the user or automatically by the radio with the aid of the speed-dependent volume control (GAL).

The radio with code 510 Audio 20 with CD changer comes not only with the general tone settings such as bass, treble, balance and fader, but is also equipped with extra tone settings. These are:
- Surround Logic 7 On/Off, with code 810 Sound system

The volume can be set as follows:
- With the + and - buttons, for selecting specific functions and volume control (S111s1) in the right multifunction steering wheel button group (S111)
- With control buttons and rotary actuator of the radio

All tone settings are made via the control buttons and the rotary actuator on the radio.

The volume is adjusted via the right multifunction steering wheel button group
Pressing the + and - button for setting specific functions and volume control increases or reduces the volume for the required audio function.

The control signals are forwarded via the following path to the radio:
- Steering Local Interconnect Network (LIN)
- Steering column tube module (N80)
- Instrument cluster (A1)
- Controller area network bus, class B (interior compartment) (CAN B)

After evaluating the control signals, the desired settings on vehicles with code 510 Audio 20 with CD changer and code 810 Sound system are transmitted via the Media Oriented System Transport (MOST) to the sound system amplifier (N40/3) and then output on the following speakers:
- Left front door speaker group (H4/1)
- Right front door speaker group (H4/2)
- Left rear door speaker group (H4/3)
- Right rear door speaker group (H4/4)
- Bass box speaker (H4/17)
- Center cockpit speaker (centerfill) (H4/27)
- Left rear surround speaker (H4/54)
- Right rear surround speaker (H4/57)

The bass box speaker audio signal travels from the radio control panel and navigation unit to the sound system amplifier via MOST and from there, via direct lines to the bass box speaker via the subwoofer amplifier (N40/9).

For vehicles except code 810 Sound system or with code 523 MB Audio 20 radio, the audio signals are finally amplified in the radio control panel and navigation unit and then sent to the following speakers via direct lines:
- Left front door speaker group
- Right front door speaker group
- Left rear door speaker group
- Right rear door speaker group
- Center cockpit speaker (centerfill)

Volume adjustment and general, extended tone settings over the control buttons and rotary actuators of the radio
Operating the radio's rotary actuator enables the volume to be raised or lowered for the desired audio function. Pressing the "Tone setting" button on the radio, enables the user to make all the general or extended tone settings. The control signals are read in and evaluated within the radio. The transmission of the settings and the speaker output is performed in the same way as described for the volume adjustment via the right multifunction steering wheel button group.

Function sequence for speed-dependent volume control
The speed-dependent volume control can be used to adapt the volume to the noise level in the vehicle interior. The speed signal from the instrument cluster is used as a reference value for this function. The speed signal is transferred to the radio over the following path:
- Instrument cluster
- CAN-B

This procedure will run automatically. After evaluating the relationship indicator, the audio output is matched to the noise level in the vehicle interior.
Depending on the vehicle speed signal, the radio raises or lowers the output level of the audio signals. The transmission of the settings and the speaker output is performed in the same way as described for the volume adjustment via the right multifunction steering wheel button group.