Shown on model 257.3 |
N40/7 | Advanced sound system amplifier control unit |
P82.62-4651-06
Location
The sound system amplifier control unit is located on a bracket in the left side of the trunk behind the side trim:
In model 257.3 at the rear of the rear bass speaker (H4/38)
In model 290 in front of the rear bass speaker
Tasks
The Advanced sound system amplifier control unit has the following tasks:
Receive signals
Signal optimization and amplification
Transmitting signals
Active engine noise compensation (AMGK) (model 290 with code 97B (Engine noise reduction via speakers))
Receive signals
The Advanced sound system amplifier control unit receives the following signals:
Power supply via circuit 30t and circuit 31
Audio muting (Mute function) from the HERMES control unit (N112/9) (with code 362 (HERMES LTE))
Optical and electrical wake-up for Media Oriented System Transport (MOST)
Control and audio signals via MOST from the following components:
Head unit (A26/17)
TV tuner control unit (N143) (with code 865 (TV tuner))
Model 257 with code B63 (Sporty engine sound) or model 290 with engine 256: Control signals (e.g. engine speed, engine load and vehicle speed) via the powertrain CAN (CAN C1) from the CDI control unit (N3/9) or from the ME-SFI control unit (N3/10)
Model 290 with code 97B (Engine noise reduction via speakers): Engine speed via the powertrain CAN (CAN C1) from the ME-SFI control unit (N3/10) and microphone signals from the following components:
Left front active engine noise compensation microphone (B25/28)
Right front active engine noise compensation microphone (B25/29)
Left rear passenger compartment active engine noise compensation microphone (B25/30)
Right rear passenger compartment active engine noise compensation microphone (B25/31)
Signal optimization and amplification
The Advanced sound system amplifier control unit optimizes the input signals by means of digital signal processing and high-quality sound optimization algorithms (Surround Sound, Easy Listening, Live, 3D Sound). The Advanced sound system amplifier control unit amplifies the input signals and assigns the output to the individual speakers.
The Advanced sound system amplifier control unit supports stereo and multi-channel entertainment channels and announcement channels (e.g. for voice output in the voice control system or navigation announcements).
Model 257 with code B63 (Sporty engine sound) or model 290 with engine 256: In order to optimize engine and exhaust system sound in the vehicle interior, the Advanced sound system amplifier control unit augments the sound panorama with simulated sound components via the speaker system.
Transmitting signals
The Advanced sound system amplifier control unit transmits electrical signals to the following components for the audio output:
Left front footwell bass speaker (H4/42)
Right front footwell bass speaker (H4/43)
Left front door sound system tweeter (H4/68)
Right front door sound system tweeter (H4/69)
Left rear door sound system tweeter (H4/70)
Right rear door sound system tweeter (H4/71)
Left front door sound system woofer/midrange speaker (H4/72)
Right front door sound system woofer/midrange speaker (H4/73)
Center instrument panel tweeter (H4/76)
Center instrument panel midrange speaker (H4/78)
Left rear door sound system midrange speaker (H4/80)
Right rear door sound system midrange speaker (H4/81)
Left front door midrange speaker (H4/86)
Right front door midrange speaker (H4/87)
Left rear surround sound system tweeter (H4/92)
Left rear surround sound system midrange speaker (H4/93)
Right rear surround sound system tweeter (H4/94)
Right rear surround sound system midrange speaker (H4/95)
Left front center overhead control panel midrange speaker (3D sound) (H4/115)
Right front center overhead control panel midrange speaker (3D sound) (H4/116)
Left center rear center midrange speaker (3D sound) (H4/117)
Right center rear center midrange speaker (3D sound) (H4/118)
Left center midrange speaker (3D sound) (H4/119)
Right center midrange speaker (3D sound) (H4/120)
Rear bass speaker amplifier (N40/14), for rear bass speaker
Active engine noise compensation (AMGK) (model 290 with code 97B (Engine noise reduction via speakers))
When the engine is running, low-frequency engine noises may be produced at cylinder shutoff, which may be considered obtrusive. The Advanced sound system amplifier control unit detects the obtrusive noises on the basis of the engine speed and the microphone signals.
The Advanced sound system amplifier control unit reduces the obtrusive noises in the vehicle interior by generating counter-noise via the following speakers:
Left footwell woofer
Right footwell woofer
Left front door sound system woofer/midrange speaker
Right front door sound system woofer/midrange speaker
Rear bass speaker, via the rear bass speaker amplifier