Radio, Stereo, and Compact Disc: Description and Operation
Audio System
LOW/MID LINE AUDIO SYSTEM - COMPONENT LOCATION
HEAD UNIT - AUDIO CONTROL DIAGRAM
NOTE:
A = Hardwired; N = Medium Speed CAN; P = MOST
HIGH LINE AUDIO SYSTEM - COMPONENT LOCATION
HEAD UNIT (HU) - AUDIO CONTROL DIAGRAM
NOTE:
A = Hardwired; N = Medium Speed CAN; P = MOST
COMPONENT DESCRIPTION
Head Units
The audio systems have three levels: low line, mid line and high line versions. All the audio systems (low, mid, high) are based around a head unit which communicates on the Media Orientated System Transport (MOST) ring and the medium speed CAN (controller area network) bus.
Low/Mid Line Head Unit
The Head Unit (HU) is located in the instrument panel and incorporates the following systems:
- HD Radio (where fitted)
- Bluetooth(R) receiver (telephone and audio streaming)
- 40 GB Hard drive
- USB controller (front)
- Audio AUX
- CD player
The low line HU contains the following functionality:
- Radio tuner
- Single disc CD (compact disc) player
- Amplifier
The HU communicates with other vehicle systems on the CAN (controller area network) bus.
Transit Mode
Transit mode is used to reduce the vehicle battery current drain whilst the vehicle is being stored or transported. Transit mode is entered/exited via a CAN (controller area network) signal from T4. In transit mode the following circuits will be disabled:
- Amplifiers
- Aux and phone call
- Clock
- Antenna power
- LED (light emitting diode) illumination
In transit mode the CAN (controller area network) port and the ON/OFF switch are the only circuits that are left active.
The CAN (controller area network) port is left open to allow the EXIT from transit mode signal to be received. The ON/OFF switch is left active to allow feedback to the driver via the HU LCD (liquid crystal display), that the unit is in Transit mode should the driver attempt to power up the HU. This will only occur when the vehicle engine is running and the battery is above 12.3 Volts.
Radio Function
The radio tuner is located in the head unit. The radio is capable of receiving AM and FM waveband and can store 18 FM pre-sets and 12 AM (amplitude modulation) pre-sets. The AM (amplitude modulation) presets are stored as follows:
European AM (amplitude modulation) Preset Storage
- 6 MW
- 6 MWa
- 6 LW
- 6LWa
NAS AM (amplitude modulation) Preset Storage
- 6 MW1
- 6 MW2
- 6 MWa
CD (compact disc) Function
The HU includes single play CD (compact disc) player. The CD (compact disc) player has all the usual functions of a CD (compact disc) player:
- CD (compact disc) play
- Previous/next track
- Shuffle tracks
- Load/eject CD (compact disc)
- Scan
- Repeat
High Line Head Unit
The high line HU contains the following functionality:
- Radio tuner.
- CD (compact disc) player (Six disc in dash changer).
- Integrated telephone control.
- Auxiliary input (for any device featuring a 3.5mm jack plug output).
The HU is woken up by CAN (controller area network) bus activity and is not woken up from the ignition aux position.
The HU is the Bus Master for the MOST system and contains the timing master for the MOST system.
Tuner
The HU incorporates a AM (amplitude modulation)/FM (frequency modulation) tuner which allows for 18 FM (frequency modulation) pre-sets and 12 AM (amplitude modulation) (6 MW and 6 LW) pre-set stations to be stored in the HU memory. The radio tuner also incorporates the following radio functions:
- Auto tune
- Traffic announcements (TA)
- RDS (radio data system) EON function
- Seek station
- Tune up/down
CD (compact disc) Player
The CD (compact disc) player is a 6 disc in dash mounted device. The CD (compact disc) multi changer is capable of playing commercial CD (compact disc)s, CD (compact disc)Rs, CD (compact disc)RWs and MP3 discs.
Random Play
The Random feature only works on the CD (compact disc), which has been selected. The Random feature plays all the tracks on the selected CD (compact disc) in a random order. All the tracks on that disc will be played before a new random sequence is played. If a new CD (compact disc) is selected while in random mode, the random mode will be cancelled and play will commence from track 1.
Repeat
The Repeat feature allows the current track to be repeated in an endless loop, when selected by the user.
MP3
The CD (compact disc) player has the capability to play MP3 files. The MP3 discs follow a format of folders and files within the folder. It is also possible to place all the files in the root directory on the CD (compact disc).
The random and repeat features follow the normal CD (compact disc) random and repeat feature functions.
Scan
Scan allows the user to play the first 10 seconds of each track on the CD (compact disc)s in the unit.
Automatic Volume Control-AVC
The AVC feature is designed to adjust output volume to compensate for the rising level noise of the vehicle as the vehicle travels faster.
There are 10 settings for AVC, where 0 = off, 1 is the lowest setting (minimum volume change with speed and 9 the maximum).
The vehicle speed signal is used to enable the HU to calculate the volume adjustment required. The vehicle speed signal is received over the CAN (controller area network) from the ABS (anti-lock brake system) control module. The signal is an average of the four wheel speed sensor signals.
Control of the AVC is carried out by the audio amplifier.
Should an invalid speed signal be received the AVC will not alter the output volume.
ICP (Integrated Control Panel)
The ICP duplicates many of the touch-screen audio user control features. Any volume setting made whilst in audio, TV, phone, navigation or voice activation mode will be memorized for that system. The ICP communicates with the IAM on the medium speed CAN (controller area network). The IAM converts control/command signals from the ICP and then distributes the information onto the MOST system to the audio system and other information and entertainment systems. No configuration procedure is required if the ICP is replaced. There is no option to calibrate the ICP using the Land Rover approved diagnostic equipment.
Touch Screen Displays
Low/mid line display
High line display
The Touch Screen Display (TSD) is located in the center of the instrument panel and is the driver control interface for the infotainment system. The TSD is connected to the MOST ring and communicates with the other components in the audio/infotainment system.
The TSD also provides driver display and control of the audio system, telephone, the rear view camera, proximity cameras, the Traffic Message Channel (TMC) and the navigation system.
The RSE and other systems are operated by 'virtual' buttons displayed on the touch screen.
Care should be taken with the TSD to ensure its correct operation
- The screen should be cleaned with a lightly, water moistened cloth. Do not use chemical agents or domestic products to clean the screen or any part of the surround.
- Only use your finger to operate the touch screen. Ensure you only use one finger to avoid incorrect entries.
- A short light press of the touch screen is sufficient. Excessive pressure can damage the screen.
Remote Audio Controls
The second and third row seat passenger can use standard headphones to listen to audio from any of the sources fitted to the vehicle. These include:
- Television
- Compact Disc (CD)
- Radio
- DVD
- AUX Input
There are four remote audio control modules, two in the rear doors incorporating the rear window switches and two in the rear load space each side of the third row seats.
The remote audio control modules allow the user to select which source to listen to. The remote controls cannot override what the driver has selected to listen to. If the driver is listening to a CD the rear passenger cannot control the CD player.
The remote audio control modules allow the user to alter the volume in the head phones, change track/disc up/down or repeat on a CD, change pre-set radio stations or tune up/down on the radio and television.
AMPLIFIERS
Harman Kardon High Line/Logic 7 Amplifier
The audio system has three amplification options:
- Internal amplification
- Harman Kardon
- Harman Kardon Logic 7
The amplifier is located under the RH (right-hand) front seat and is connected to the audio system via the MOST bus.
STEERING WHEEL CONTROLS
Steering Wheel Audio Controls
The HU can be remotely controlled via steering wheel mounted controls. The steering wheel controls are mounted to the right hand side of the steering wheel.
The switches are a resistive ladder type. The HU supplies a reference voltage to the switches, which then return an altered voltage to the HU depending on which switch is pressed.
The controls allow the user to adjust the volume, change CD (compact disc) tracks/radio pre-sets, answer and end a phone call (where a phone is fitted) and use the voice recognition system.
SATELLITE DIGITAL AUDIO RADIO SERVICE (SDARS NAS only)
The SDARS systems operate in the S-Band frequency range (2.3 GHz) and, as a result of the use of satellite transmission have the ability to provide CD (compact disc) quality audio broadcasts over very large areas (typically continents). SDARS service providers transmit a signal from their up-link facility (which is the original point of transmission of data, voice or other information through an antenna system) to a satellite where the signal is then down linked to both the terrestrial repeater network and the individual SDARS car radios. The radio switches between the satellite signal and the repeater signal depending on the strength of the signal at any given time.
Land Rover will be using the Sirius Satellite Radio service provider in the USA.
The Sirius SDARS systems comprise:
- Satellites
- Ground repeaters
- Up-link ground stations
- Radio receiver systems
The Sirius SDARS system uses three satellites on an inclined elliptical orbit. This ensures that each satellite spends approximately 16 hours a day over the continent of the USA, with at least one satellite over the country at any one time.
The satellites beam their signals down to the ground where the signal is picked up by receivers or is transmitted to repeater stations to cover built up areas where the signal is obscured.
TRAFFIC MESSAGE CHANNEL (TMC)
The TMC system is a European only system whereby traffic information is received by the TMC tuner and used by the navigation computer to recalculate the route being used to avoid the traffic disruption. This system information is broadcast on the RDS (radio data system) data carriers.