Radio, Stereo, and Compact Disc: Description and Operation
Audio System
HEAD UNIT (HU) - AUDIO SYSTEM COMPONENT LOCATION
HEAD UNIT (HU) - AUDIO CONTROL DIAGRAM
NOTE:
A = Hardwired; N = Medium Speed CAN; P = MOST
COMPONENT DESCRIPTION
Head Unit
NOTE:
The base level audio head unit comprises of a single disc CD (compact disc) player and an integral amplifier, all other functions of the unit are comparable with the 6 disc unit.
The audio system is based around a head unit which communicates on the Media Orientated System Transport (MOST) ring and the medium speed CAN (controller area network) bus.
The head unit 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 18 AM (amplitude modulation) (9 MW and 9 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
- Scan
- PTY
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) 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). 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.
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 one amplification option:
- 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. Speaker connections are hardwired.
Steering Wheel Control Switches
The HU can be remotely controlled via steering wheel mounted controls. The audio steering wheel controls are mounted to the RH (right-hand) side of the steering wheel with the voice recognition system control (push to talk switch) located on the LH (left-hand) side of the steering wheel behind the speed control switches.
The Steering wheel control switches allow the driver to:
- Change audio system mode
- Adjust audio volume
- Change CD (compact disc) tracks
- Activate the voice recognition system
- Change radio pre-sets
- Tune up/down
- Answer and end a phone call (where a phone is fitted)
- Use the voice recognition system.
The switches operate on a resistive ladder principle. A voltage is supplied to the switches and dependant upon which button is pressed a reduced voltage is returned to the head unit.
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.
The information is used by the navigation system to avoid traffic disruptions on a planned route.For additional information, refer to Navigation System Description and Operation