Initial Inspection and Diagnostic Overview
RADIO [AUDIO]1. Multipath Noise
- Signals from an FM transmitter are a high frequency and similar to beams of light because they do not bend around corners, but they do reflect. Since FM signals can be reflected by obstructions, it is possible to receive both the direct signal and the reflected signal at the same time. This causes a slight delay in reception and may be heard as a broken sound or a distortion.
2. Flutter/skip Noise
- Signals become weak in valleys between mountains, tall building, and other obstacles. When the vehicle passes through such an area the reception conditions may change suddenly, resulting in annoying noise.
3. Stereo and Monaural Receptions
- As signals become weak, noise may appear more in stereo reception. Comparing to stereo reception, noise in monaural receptions is relatively less striking.
Measures in Audio System
Separation control
- Utilizing the characteristic of monaural reception that noise is relatively less striking than stereo reception, the audio system automatically changes the reception from stereo to monaural and lessens annoying noise when signals become weak or a multipath phenomenon occurs.
High tone control
- When signals become weak or a multipath phenomenon occurs, the audio system restrains volume level in high frequency band and lessens annoying noise.
Effect Setting of Separation Control and High Tone Control
- The separation and high tone controls influence sound quality, Therefore they are specifically tuned for individual model. (Comparison of characteristic must be done on the same models)
Remarks
- Signals tend to reach longer distances in the night. It is conspicuous in AM signals, several audio functions may stop due to foreign broadcasting station or noise. though the audio system restrains sensitivity of SEEK and SCAN functions in the night, the audio system may select other than desired broadcasting station when signals are considerably strong. This function is linked to the parking light. When the parking light or headlight is turned on, SEEK and SCAN may not function for weak signals.
AUDIO CD [AUDIO]
- The CD player/changer has been designed to play CDs bearing the identification logo,COMPACT DISC DIGITAL AUDIO, as shown. No PACT IMPACT other discs can be played on the CD player/changer other than MP3 applicable one.
- The CD player/changer may not play the following CD:
- Defective CD (e.g., cracked, badly bent, rough edges, scratch, dirty CD condensation)
- 8 cm (3 in) CDs accessories (e.g., 8 cm (3 in) disc adapter, sticker, label)
- Nonstandard CD (e.g., Diameter/thickness is out of specification)
Specification: 119.7-120.3 mm (4.668-4.692 in) of diameter, 12+0.3 or -0.1 mm (0.047+0.012 or 0.004 in) of thickness
- Do not use non-conventional discs. The CD player/changer could be damaged.
Examples:
- Although the same physical size as the compact disc, SACD uses a different kind of digital audio signal, Direct Stream Digital.
- The CD player/changer may not play the CD-RI RW properly due to the disc condition (excluding the MP3).
MP3-Formatted File
Outline of CD-R and CD-RW
- Definition
- CD-R: The CD-R is a non-rewritable version. Once a section of a CD-R is written, it cannot be erased or rewritten.
- CD-RW: The CD-RW is a re-writable version of CD-ROM and can be written the data an unlimited number of times.
- Since a reflected laser beam amount of the CD-R/RW is less than the reflected laser beam amount of the conventional CD media, the CD player/changer may not play the CD-R/RW or have the sound jumped.
- Since the recording quality of the CD-R/RW vary widely, some CD-R/RW may not be played.
Recording method
- There are two methods for recording.
- Classification by recorder
- Record the audio data in the audio-CD by audio recorder
- The price of the audio recorder and original audio-CD includes the copyright fee.
- Recorded the audio data in the conventional data-CD by the personal computer
- The data-CD is cheaper than the audio-CD. But, there is a CD with the low quality.
- Classification by audio data Uncompression/compression
- Uncompressed audio data
- The CD-R/RW player can play the Uncompressed audio data.
- Compressed audio data
- It is possible to record the large quantity of music in a disc. The sound quality varies depends on the audio data compression format. The compressed audio data can be played on the applicable player only.
- Type of compression format:
- MP3: MPEG Audio Layer 3 - Mazda genie MP3 applicable CD player is available.
- WMA: Windows Media Audio
- ATRAG: Adaptive TRansform Acoustic Coding
MP3
- The following condition should be met in order to record the MP3-formatted data on the MP3 applicable CD player:
