Component description for sound system amplifier control unit

P82.62-4138-06

P82.62-3788-06

P82.62-4139-06

P82.62-3789-06

Location

The sound system amplifier control unit is located in the luggage compartment behind the cover on a bracket, on model 212.0/1 under the rear shelf and on model 212.2 up to 01.03.2015 in the luggage compartment at the left sidewall. On model 212.2 as of 02.03.2015, the sound system amplifier control unit is centrally located in the luggage compartment under the mat.

Tasks

 Receive signals

 Decoding signals

 Support, amplification and processing of signals

 Transmitting signals

Receive signals

The input signals are read in via the following connections:

 Media Oriented System Transport (MOST)

 Direct lines

Media Oriented System Transport (MOST)

The sound system amplifier control unit is a MOST subscriber and receives, in addition to control communication with the COMAND controller unit (A40/3), audio signals from the following components:

 COMAND control unit

 As of 02.03.2015: Tuner unit (with CODE 536 (SIRIUS satellite radio), CODE 537 (Digital radio) or CODE 865 (TV tuner))

 Up to 01.03.2015: digital TV tuner (A90/3) (with CODE 865 (TV tuner))

 Up to 01.03.2015: Satellite Digital Audio Radio (SDAR) control unit (N87/5) (with CODE 536 (SIRIUS satellite radio))

 Up to 01.03.2015: Digital Audio Broadcasting control unit (N87/3) (with CODE 537 (Digital radio))

 Up to 01.03.2015: Media interface control unit (N125/1) (with CODE 518 (Media Interface))

Direct lines

 Power supply over circuit 31 and circuit 30

 Audio muting (MUTE) from the emergency call system control unit (N123/4) (with CODE 348 (Emergency call/assist system)) or telematics services communications module (N112/2) (with CODE 350 (Ecall Europe emergency call system, Gen. 2))

 Visual and electrical wake-up

 Signals from sound system microphone (B25/6)

Decoding signals

Decoding copy-protected audio signals on basis of latest DSP (Digital Signal Processing) technology.

 DSP means that for the audio range, audio tracks are processed using mathematical algorithms with the objective of improving the acoustic sound characteristics.

Support, amplification and processing of signals

 Supporting surround sound (Bang&Olufsen)

 Supporting 2 stereo entertainment channels and 3 announcement channels (e.g. for voice output of navigation instructions)

 Amplifying decoded audio signals

 Radio signals

 Vehicle speed signal for speed-dependent volume control (SDV [GAL])

 Signals from sound system microphone for dynamic volume adaptation, dynamic range optimization (DRO)

Transmitting signals

Direct lines

 5x line out (+ and –) for rear bass speaker amplifier (N40/9) (up to 01.03.2015)

 Remote for the bass speaker amplifier (up to 01.03.2015)

 Output of acoustic signals (BEEPs), digital multiple channel output and output of the decoded audio signals adapted to the volume as well as amplified audio signals via the following speakers: Left left front door speaker (H4/1), right front door speaker (H4/2), left rear door speaker (H4/3) (as of 02.03.2015), right rear door speaker (H4/4) (as of 02.03.2015), bass speaker (H4/17) (model 212.0/1) or bass speaker (H4/29) (model 212.2) (as of 02.03.2015), left front door sound system bass speaker (H4/64) (as of 02.03.2015), Right front door sound system bass speaker (H4/65) (as of 02.03.2015), left front door speaker, mirror triangle (H4/23), right front door speaker, mirror triangle (H4/24), center instrument panel speaker (H4/27), left rear surround speaker (H4/54), right rear surround speaker (H4/57), left rear door sound system tweeter (H4/71), right rear door sound system tweeter (H4/72)

Function

The sound system amplifier control unit is actuated via the COMAND controller unit. The COMAND controller unit also provides all menus for user guidance.

For optimized speed-dependent volume control (SDV), the sound system amplifier control unit evaluates the following signals:

 Speed signal from the COMAND controller unit, over MOST

 Signals from the sound system microphone, via a direct line