Overview
This document contains information on:
Function of the speaker system
Restricted speaker actuation
Actuation of the speakers during an emergency call
Support of communication in the vehicle (dependent on model and equipment installed)
General
The task of the speaker system is to output the audio information from various systems via the speakers in the vehicle. Sources for the audio information can be the radio, media or the telephone, for example. Depending on the equipment installed, the speaker system is controlled either by the multimedia system control or by the sound system amplifier control unit.
Function of the speaker system
Each source converts the audio information into analog audio signals. Then an amplifier amplifies the analog audio signals and transmits them to the speakers. Depending on the equipment installed, the amplifier is either integrated in the multimedia system control or is installed in the vehicle as an independent control unit.
The subwoofer amplifier is optionally used. This additionally amplifies the analog audio signals to the rear subwoofer.
Each speaker is optimized for its tasks, e.g. according to the various frequency ranges. The speakers installed differ in terms of quality, number and installation location depending on the model and equipment level.
The user can adjust the volume and tone of the speaker system using the multimedia system. When an emergency call is triggered, the telematics services control unit mutes the audio sources.
Restricted speaker actuation
During voice output, the amplifiers primarily actuate the speakers in the front area of the vehicle.
Actuation of the speakers during an emergency call
For the emergency call system, the center instrument panel speaker is connected directly to the telematics services control unit. This means that the function of the emergency call is assured independently of the speaker system.
In addition, the telematics services control unit transmits a signal with the request for the mute function to the sound system amplifier control unit or to the multimedia system control.
Support of communication in the vehicle (dependent on model and equipment installed)
In some vehicles entertainment to all the seat rows can be made easier with acoustic support. To achieve this, the speaker system also outputs the words spoken in one seat row in the speakers assigned to the other seat row.
In the basic variant, the hands-free system microphones records what is spoken in the front seats and the speakers in the rear emit the signals too. This means that what is spoken in the first seat row can also be heard better in the second seat row. With the maximum equipment, additional microphones are fitted in the rear, so that communication between the seat rows can be supported in both directions by the speaker system.
The function is switched on and off using the multimedia system control. Different volume levels can also be selected to support communication.
Function schematics | |||
Function schematic for actuating speakers | Model 118, 177 except engine 139, model 247 | ||
Model 118, 177 with engine 139 | |||
Model 167 | |||
Model 213, 238, 257 as of model year 2021 | |||
Model 238 as of model year 2021 | |||
Model 293 | |||
Further basic functions | |||
Volume adjustment to noise level, basic function | |||
Engine sound, basic function | Vehicles with sporty engine sound and vehicles with code 97B (Engine noise reduction via speakers (EOC)) | ||
Radio mode,basic function | |||
Media mode,basic function | |||
TV mode, basic function | Model all (CAR) | ||
Telephone, basic function | |||
Multimedia system control, basic function | |||
Emergency call system, basic function | Model all (CAR) | ||
Control units | |||
Sound system amplifier control unit, basic function | Vehicles with code 810 (Premium sound system) or code 811 (with high-end sound system), Vehicles with code 97B (Engine noise reduction via speaker (EOC)) and AMG vehicles with engine 139, 256 | ||
Components | |||
Subwoofer amplifier, basic function | Model all (CAR) |