Audi A8 2005 User Manual

Service Training

Audi Infotainment Systems ‘05

z Bang & Olufsen Audio System z Digital radio tuner z Te l e v ision hybri d t u n e r

Self-Study Programme 366

Digital Infotainment

Audi is a name synonymous with outstanding, innovative automotive engineering. A number of brand names spring to mind: quattro®, FSI® and MMI, the pioneering Multi Media Interface, are just a few of the many achievements that have had a profound impact on automotive manufacturing. Once again, the brand name Audi lives up to its slogan "Vorsprung durch Technik".

With the digital radio, the television hybrid tuner and the Bang & Olufsen Audio System, Audi offers digital infotainment systems that represent a significant addition to the standard product package in terms of variety and quality.

Customary ease of use

One of the outstanding features of cutting-edge technology is its ease of use. The tried and tested, and yet still pioneering, operating concept of the MMI (Multi Media Interface) ensures maximum functionality and ease of use thanks to its intuitive navigation technology.

The large, high-resolution screen makes for clear presentation of all operator menus in the MMI, as well as user-friendly presentation of all relevant additional information. The digitisation of signals greatly simplifies the handling of information: This simplifies the processing of audio and visual signals while reducing the volume of data. Unlike analog broadcasting, digital information can be reproduced and broadcast almost without loss of quality.

Video and audio can now be combined with textual information

Digital reception also opens up additional possibilities for information processing and distribution. In addition to the actual broadcast content, innovative services are broadcast with digital programmes. These are: Audio and visual signals can combined with textual information thanks to digital broadcasting. This information can refer to current programmes such as title, artist (with DAB) and the Electronic Programme Guide (EPG) for DVB-T. On the other hand, the information can also be unrelated to the current programme, such as messages, weather reports or traffic messages for DAB. These new features will make digital receivers even more attractive in future.

Into the lead: with design & performance

Contents

Bang & Olufsen Audio System. . . . . . . . . . . . . . . . . . . . . . 4

Overview of the components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Function diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Treble loudspeakers in dash panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Integrated loudspeaker systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Digital sound package control unit J525 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Digital sound package control unit 2 J787. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Digital radio tuner (DAB) . . . . . . . . . . . . . . . . . . . . . . . . . . 18

DAB technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Digital radio R147 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

TV hybrid tuner (analog and DVB-T) . . . . . . . . . . . . . . . . 24

DVB-T technology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

TV hybrid tuner. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Aerials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Diagnostics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

This self-study programme teaches the design and function of new vehicle models, new automotive components or new technologies.

The self-study programme is not a workshop manual! All values given are intended as a guideline only, and refer to the software version valid at the time of publication of the SSP.

Please refer to the relevant Service Literature for current inspection, adjustment and repair instructions.

NoteReference

Bang & Olufsen Audio System

Bang & Olufsen is a Danish manufacturer of high-end entertainment electronics. Bang & Olufsen attaches particular importance to performance, design, human expectations and perfect workmanship. The goal for the development of the Bang & Olufsen Advanced Sound System was to build the best sound system ever used in a motor vehicle. This applies both to the sound and to the ease of use and the design.

Particular attention was paid to the acoustic quality of the sound system. A motor vehicle places special demands on a sound system. The listeners are not seated at the auditory centre of the loudspeakers. They are seated at different distances to the loudspeakers. The loudspeaker position is, to a large extent, predefined by the requirements relating to the occupant cell. The materials used to build the vehicle body and interior also affect the quality of the sound system.

Acoustic lens

– 2 x 19 mm treble loudspeaker

Centre

– 70 mm centre treble loudspeaker

Overview of the components

The Bang & Olufsen Advanced Sound System comprises a total of 14 loudspeakers. The loudspeakers are driven by 2 amplifiers with 14 output channels. The amplifiers have a total power output of over 1000 W.

Front doors

– 90 mm mid-range loudspeaker – 140 mm bass loudspeaker

Rear shelf

– 200 mm long-stroke subwoofer – 2 x 70 mm mid-range loudspeaker

Rear doors

– 25 mm treble loudspeaker – 133 mm bass loudspeaker

Amplifier

J787 Digital sound package control unit 2 – 4 x 125 W Class D – 1 x 250 W Class D

J525 Digital sound package control unit – 9 x 28 W MOST DSP

366_054

Bang & Olufsen Audio System

Function diagram

MOST

Optical fibre break

R14 R105 R158 R103

R164

Telephone audio IN

J525

Line Out

R21

R16 R106 R104

R23

V344

Line In

J787

R157R159

R20

R22

V345

Legend

J525 Digital sound package control unit J787 Digital sound package control unit 2

R14 Rear left treble loudspeaker R16 Rear right treble loudspeaker R20 Front left treble loudspeaker R21 Bass loudspeaker, front left R22 Front right left treble loudspeaker R23 Bass loudspeaker, front right R103 Front left mid-range loudspeaker R104 Front right mid-range loudspeaker R105 Rear left mid-range loudspeaker

R160

366_001

R106 Rear right mid-range loudspeaker R157 Subwoofer in rear shelf R158 Mid-range/treble loudspeaker, centre R159 Mid-range/treble loudspeaker, rear left R160 Mid-range/treble loudspeaker, rear right R164 Microphone unit in front roof module

V344 Front left treble loudspeaker control motor V345 Front right treble loudspeaker control motor

Bang & Olufsen Audio System

Treble loudspeakers in dash panel

Two 19 mm treble loudspeakers are fitted in the dash panel. The loudspeakers are extended by an electric motor when the MMI is switched on. The extended position of the loudspeaker is monitored by an integrated Hall sender.

An integrated worm gear is used to reduce the motor speed to the crank speed. The rotation of the crank is translated via a connecting rod to a linear movement of the treble loudspeaker.

If the load on the drive is too high when the treble loudspeakers are extending, e.g. because someone is holding on to them, the connecting rod disengages from the crank drive. The roller on the crank slides along the slotted connecting rod. The worm gear is thus protected against mechanical damage. If the treble loudspeakers are subsequently retracted fully, the connecting rod re-engages in the crank during this movement so that the loudspeakers subsequently extend fully.

If an extended loudspeaker is pushed down mechanically, e.g. by hand, the mechanism behaves in exactly the same way. The connecting rod is disengaged when the loudspeaker is pushed down. If the treble loudspeaker is retracted by MMI, the crank is moved into the lowest position and the connecting rod re-engages.

Treble loudspeaker retracted

Loudspeaker

366_005

Acoustic lens

An acoustic lens which provides optimal sound radiation into the vehicle interior is attached to the treble loudspeakers. The acoustic lens allows optimally directed reflection of the sound into the vehicle interior. The lens shape specially designed for well-balanced horizontal sound distribution. The result is much better acoustics than in a conventional system, where the front windscreen, among other things, acts as a sound reflector.

Con-rod

Crank

Motor

Treble loudspeaker extended

366_006

Worm gear

Drive

366_008

366_015No reflection off windscreen

Integrated loudspeaker systems

All mid-range loudspeakers, bass loudspeakers and the subwoofers are designed as fully integrated loudspeaker systems. The housings for the respective loudspeakers have been optimised for minimum vibration. This prevents uncontrolled vibration of the vehicle body and interior trim panels. The result is enhanced sound clarity and definition. Noise radiation away from the vehicle is greatly reduced since the body's outer skin no longer functions simultaneously as a loudspeaker box.

However, due to the smaller housing volume compared to non-integrated loudspeaker systems, additional amplifier power is required to achieve the same sound pressure level in each loudspeaker. The sound pressure level is a measure of the volume of a loudspeaker and is measured in dB ( decibels). A 10 dB increase in sound pressure is equivalent to doubling the volume.

Wide horizontal sound radiation

366_016

366_055

366_056

Bang & Olufsen Audio System

Digital sound package control unit J525

The digital sound package control unit consists of an audio amplifier equipped with a powerful digital signal processor (in short: DSP).

The amplifier converts the digital stereo signal from the MOST bus to the individual audio channels and controls 9 loudspeakers and the digital sound package control unit 2 J787.

In addition, the DSP adapts the audio signals to the specific sound characteristics of the Audi A8 ‘03.

366_058

Automatic source volume correction

Different audio sources, such as radio, CD, DAB, etc., transmit different music and voice at different volumes. This is principally due to the fact that different radio stations broadcast their programmes at different volumes, and because audio CDs are recorded at different volumes.

The digital signal processor in the amplifier recognises the volume and adjusts all sources in such a way that the listener notices no change in volume after selecting a different audio source, e.g. from radio to CD.

Level

Source 1

Source 2

Frequency

Signal processor

Level

Frequency

366_017

Frequency response correction

The acoustic properties of vehicle interiors are less than optimal, unlike rooms designed specially for this purpose in buildings. To optimise in-vehicle acoustics, the digital signal processor corrects the frequency response, i.e. bass, mid range and treble are adjusted digitally. Sound frequencies that are amplified by the vehicle interior are output in an attenuated form by the amplifier. Sound frequencies that are heavily attenuated by the vehicle interior are output in an amplified form. The digital signal processor also functions as a frequency splitter.

The sounds transmissible from the respective loudspeakers are transmitted to the loudspeaker. A treble loudspeaker receives only high frequencies, since the high energy of the low frequencies would destroy the treble loudspeaker coil. A bass loudspeaker receives only low frequencies, since the large mass of the loudspeaker coil would be much too slow for the transmission of high frequencies. The result for the listener is a well-balanced auditory experience across the frequency range from very low to very high frequencies.

Highpass filter

Treble loudspeaker

Frequency

Lowpass filter

Bass loudspeaker

Frequency

Level

Frequency

Signal processor

Level

1 attenuated frequency 2 amplified frequency

Bass and treble are also corrected digitally in the MMI and additionally in the amplifier for radio or TV, CD, DAB.

366_018

Fabric and leather interior trims have different acoustic properties. To adapt the loudspeaker signals optimally to the vehicle, the interior trim material can be selected in the amplifier configuration using the diagnostic tester.

+ 25 hidden pages