Radio, Stereo, and Compact Disc: Description and Operation
AUDIO / VIDEO: AUDIO AND VISUAL SYSTEM: SYSTEM DIAGRAM
1. SYSTEM DIAGRAM (for 8 Speakers)
2. SYSTEM DIAGRAM (for 14 Speakers)
SYSTEM DESCRIPTION
1. CD (Compact Disc) PLAYER OUTLINE
(a) A compact disc player uses a laser pickup to read digital signals recorded on a compact disc (CD). By converting the digital signals to analog, it can play music and other content.
CAUTION:
Do not look directly at the laser pickup because the CD player uses an invisible laser beam. Be sure to operate the player only as instructed.
NOTICE:
* Do not disassemble any part of the CD player.
* Do not apply oil to the CD player.
* Do not insert anything but a CD into the CD player.
(b) Usable discs
(1) This player can play only audio CDs, CD-Rs (CD-Recordable), and CD-RWs (CD-ReWritable) that have any of the following marks:
(c) Precautions for use of discs
NOTICE:
* Copy-protected CDs cannot be played.
* CD-Rs and CD-RWs may not be played depending on the recording conditions or characteristics of the discs, or due to damage, dirt, or deterioration caused by leaving the discs in the cabin for a long time.
* Unfinalized CD-Rs and CD-RWs cannot be played.
* Keep the discs away from dirt. Be careful not to damage the discs or leave your fingerprints on them.
* Hold discs by the outer edge and center hole with the label side up.
* Leaving the disc exposed halfway out of the slot for a long time after pressing the disc eject button may cause deformation of the disc, making the disc unusable.
* If discs have adhesive tape, stickers, CD-R labels, or any traces of such labels attached, the discs may not be ejected or player malfunctions may result.
* Keep the discs away from direct sunlight (exposure to direct sunlight may cause deformation of the disc, making the disc unusable).
* Do not use odd-shaped CDs because these may cause player malfunctions.
* Do not use discs whose recorded portion is transparent or translucent because they may be unable to be properly inserted, ejected, or played.
HINT
* When it is cold or raining, if the windows mist up, mist and condensation may form in the player. In such a cases, the CD may skip or stop in the middle of play. Ventilate or dehumidify the cabin for a while before using the player.
* The CD may skip if the player experiences strong vibrations when the vehicle is driven on rough road or similar uneven surfaces.
(d) Cleaning
NOTICE:
Do not use a lens cleaner because it may cause a malfunction in the pickup portion of the player.
(1) If dirt is on the disc surface, wipe it clean with a soft dry cloth, such as an eyeglass cleaner for plastic lenses, from the inside to the outside in a radial direction.
NOTICE:
* Pressing on the disc by hand or rubbing the disc with a hard cloth may scratch the disc surface.
* The use of solvent such as a record spray, antistatic agent, alcohol, benzine, and thinner, or a chemical cloth may cause damage to the disc, making the disc unusable.
2. MP3/WMA OUTLINE
(a) Playable MP3 file standards
(b) Playable WMA file standards
(c) ID3 tag and WMA tag
(1) Additional textual information called ID3 tags can be input to MP3 files. Information such as song titles and artist names can be stored.
HINT
This player is compatible with the ID3 tags of ID3 Ver. 1.0 and 1.1, and ID3 Ver. 2.2 and 2.3 (the number of characters complies with ID3 Ver. 1.0 and 1.1).
(2) Additional textual information called WMA tags can be input to WMA files. Information such as song titles and artist names can be stored.
(d) Usable media
(1) Only CD-ROMs, CD-Rs (CD-Recordable), and CD-RWs (CD-ReWritable) can be used to play MP3/WMA files.
NOTICE:
* CD-Rs and CD-RWs are more easily affected by a hot and humid environment than discs used for normal audio CDs. For this reason, some CD-Rs and CD-RWs may not be played.
* If there are fingerprints or scratches on the disc, the disc may not be played or the CD may skip.
* Some CD-Rs and CD-RWs deteriorate if they are left in the cabin for a long time.
* Keep CD-Rs and CD-RWs in a storage case that is impenetrable to light.
(e) Usable media format
(1) Usable media format
HINT
* As for MP3/WMA files written in any format other than those above, the contents of the files may not be playable normally or the file names or folder names may not be displayed correctly.
* This player is compatible with multi-session discs and can play CD-Rs and CD-RWs on which MP3/WMA files are added. However, only the first session can be played.
* Discs whose first session includes both music data and MP3 or WMA format data cannot be played.
(2) Standard and restrictions
(f) File names
(1) Only files with an extension of ".mp3" or ".wma" can be recognized and played as MP3 or WMA files.
(2) Save MP3 or WMA files with an extension of ".mp3" or ".wma".
NOTICE:
If saving non-MP3 or non-WMA files with an extension of ".mp3" or ".wma", those files are wrongly recognized as MP3 or WMA files and played. A loud noise may occur and damage to the speakers may result.
3. AVC-LAN DESCRIPTION
(a) What is AVC-LAN?
AVC-LAN, an abbreviation for "Audio Visual Communication Local Area Network", is a united standard developed by the manufacturers in affiliation with Toyota Motor Corporation. This standard pertains to audio and visual signals as well as switch and communication signals.
(b) Purpose:
Recently, car audio systems have rapidly developed and the functions have vastly changed. The conventional car audio system is being integrated with multi-media interfaces similar to those in navigation systems. At the same time, customers are demanding higher quality from their audio systems. This is merely an overview of the standardization background. The specific purposes are as follows:
(1) To solve sound problems, etc. caused by using components of different manufacturers through signal standardization.
(2) To allow each manufacturer to concentrate on developing products they do best. From this, reasonably priced products can be produced.
HINT
* If a short to +B or short to ground is detected in the AVC-LAN circuit, communication is interrupted and the audio system will stop functioning.
* If the audio system has a navigation system installed, the multi-display unit acts as the master unit. If the navigation system is not installed, the audio head unit acts as the master unit instead. If the navigation receiver assembly is installed, it is the master unit.
4. COMMUNICATION SYSTEM OUTLINE
(a) Components of the audio system communicate with each other via the AVC-LAN.
(b) The master component of the AVC-LAN is a radio receiver assembly with a 60 to 80 Ohms resistor. This is essential for communication.
(c) If a short circuit or open circuit occurs in the AVC-LAN circuit, communication is interrupted and the audio system will stop functioning.
5. DIAGNOSTIC FUNCTION OUTLINE
(a) The audio system has a diagnostic function (the result is indicated on the master unit).
(b) A 3-digit hexadecimal component code (physical address) is allocated to each component on the AVC-LAN. Using this code, the component in the diagnostic function can be displayed.
6. "BLUETOOTH" OUTLINE
(a) "Bluetooth" is a trademark owned by Bluetooth SIG. Inc.
(b) "Bluetooth" is a new wireless connection technology that uses the 2.4 GHz frequency band. This makes it possible to connect a cellular phone ("Bluetooth" compatible phone*) to the radio receiver assembly (the "Bluetooth" system is built-in) through the handsfree function of the cellular phone, even if it is in a pocket or bag. As a result, it is not necessary to directly connect the radio receiver assembly to the cellular phone.
HINT
* *: Some versions of "Bluetooth" compatible cellular phones may not function.
* The communication performance of "Bluetooth" may vary depending on obstructions or radio wave conditions between communication devices, electromagnetic radiation, communication device sensitivity and antenna capacity.
(c) "Bluetooth" audio function
(1) The "Bluetooth" built into the navigation receiver assembly and a "Bluetooth" compatible portable audio player* can be connected using a "Bluetooth" wireless connection. This enables files stored in the portable audio player to be heard from the vehicle speakers. In addition, operations such as play/stop can be performed directly from the navigation receiver assembly.
*: Some versions of "Bluetooth" compatible audio players may not be able to operate using the "Bluetooth" function, or music may play, but functions available using the navigation receiver assembly may be limited.
(2) Available "Bluetooth" audio devices
HINT
The amount of remaining battery charge displayed on the navigation receiver assembly may be different from that of the portable player.
7. RADIO DESCRIPTION
(a) Radio frequency band
(1) Radio broadcasts use the radio frequency bands shown in the table below.
(b) Service area
(1) The service areas of AM and FM broadcasts are vastly different. Sometimes an AM broadcast can be received very clearly but an FM stereo broadcast cannot. FM stereo has the smallest service area, and is prone to pick up static and other types of interference such as noise.
(c) Radio reception problems
HINT
In addition to static, other problems such as "phasing", "multipath", and "fade out" exist. These problems are not caused by electrical noise, but by the radio signal propagation method itself.
(1) Phasing
AM broadcasts are susceptible to electrical interference and another kind of interference called phasing. Occurring only at night, phasing is the interference created when a vehicle receives 2 radio wave signals from the same transmitter. One signal is reflected off the ionosphere and the other signal is received directly from the transmitter.
(2) Multipath
Multipath is a type of interference created when a vehicle receives 2 radio wave signals from the same transmitter. One signal is reflected off buildings or mountains and the other signal is received directly from the transmitter.
(3) Fade out
Fade out is caused by objects (buildings, mountains, and other such large obstacles) that deflect away part of a signal, resulting in a weaker signal when the object is between the transmitter and vehicle. High frequency radio waves, such as FM broadcasts, are easily deflected by obstructions. Low frequency radio waves, such as AM broadcasts, are much more difficult to deflect.
(d) Noise problem
Technicians must have a clear understanding about each customer noise complaint. Use the following table to diagnose noise problems.
HINT
If the noise does not match the examples above, refer to the descriptions about phasing and multipath.
8. AUTOMATIC SOUND LEVELIZER (ASL) FUNCTION OUTLINE
(a) The ASL function automatically adjusts the sound volume in order to enable clear audio quality even when vehicle noise increases (as vehicle speed increases, the volume is turned up, etc.).
Vehicle speed signals are received from the combination meter assembly and used by ASL control.
9. RBDS FUNCTION OUTLINE (BROADCAST IN NORTH AMERICA ONLY)
The Radio Broadcast Data System (RBDS) is broadcast through conventional FM radio broadcasts. Information such as song names, traffic information, broadcast station names, etc. can be received.
10. SDARS SYSTEM FUNCTION OUTLINE (BROADCAST IN NORTH AMERICA ONLY)
Satellite Digital Audio Radio Service (SDARS) is a satellite digital radio broadcast provided by Sirius XM Radio Inc. The broadcast (pay-type) is performed through satellites and terrestrial repeater networks. Several unique channels are available, and even if a vehicle changes locations, the same information can be received without breaks. Information such as song names, broadcast station names, etc. can be received. Also, traffic information can be received and displayed on the navigation screen.
NOTICE:
To receive audio-visual pay-type broadcasts, the customer must enter into a pay-type contract with XM Satellite Radio Inc. After entering into a contract, registration of the XM Radio ID is required. Also, if parts are replaced, the XM Radio ID must be reregistered.