COMPRESSED AUDIO FILES (MP3/
WMA/AAC)
Explanation of terms
.MP3 —MP3 is short for Moving
Pictures Experts Group Audio Layer 3.
MP3 is the most well known com-
pressed digital audio file format. This
format allows for near “CD quality”
sound, but at a fraction of the size of
normal audio files. MP3 conversion of
an audio track can reduce the file size
by approximately a 10:1 ratio (Sam-
pling: 44.1 kHz, Bit rate: 128 kbps)
with virtually no perceptible loss in
quality. The compression reduces cer-
tain parts of sound that seem inaudible
to most people.
. WMA —Windows Media Audio (WMA) is
a compressed audio format created by
Microsoft as an alternative to MP3. The
WMA codec offers greater file compres-
sion than the MP3 codec, enabling
storage of more digital audio tracks in
the same amount of space when
compared to MP3s at the same level
of quality. .
Bit rate —Bit rate denotes the number
of bits per second used by a digital
music file. The size and quality of a
compressed digital audio file is deter-
mined by the bit rate used when
encoding the file.
. Sampling frequency —Sampling fre-
quency is the rate at which the samples
of a signal are converted from analog to
digital (A/D conversion) per second.
. Multisession —Multisession is one of
the methods for writing data to media.
Writing data once to the media is called
a single session, and writing more than
once is called a multisession.
. ID3/WMA Tag —The ID3/WMA tag is
the part of the encoded MP3 or WMA
file that contains information about the
digital music file such as song title,
artist, album title, encoding bit rate,
track time duration, etc. ID3 tag in-
formation is displayed on the Album/
Artist/Track title line on the display.
* Windows
®and Windows Media®are
registered trademarks or trademarks of
Microsoft Corporation in the United States
of America and/or other countries.
Playback order
. The folder names of folders not contain-
ing compressed audio files are not
shown in the display.
. If there is a file in the top level of a
disc/USB, “Root Folder” is displayed.
4. Audio system
4-7
11. Troubleshooting guide
11-6
COMPACT DISC (CD) PLAYER
SymptomPossible cause Possible solution
Music cannot be played back. The disc is inserted upside down.Insert a CD with the label side facing up.
Moisture condensation occurs inside the unit. Wait until the moisture evaporates (approximately 1 hour).
The cabin temperature is too high. Wait until the cabin temperature becomes moderate.
The disc is scratched or dirty. A disc is not always
playable if it is scratched. Wipe off any dirt from the disc.
Depending on the condition in which they are
stored, discs may become unreadable due to
deterioration (for example, keeping the discs in the
passenger compartment, etc.). Change the disc with a deterioration-free disc. Do
not use a deteriorated disc. The label surface of the
disc may crack or chip, and the layer of the label
surface may eventually peel off.
The compressed audio files cannot be played back. If both music CD files (CD-DA data) and compressed audio files (MP3 data, etc.) are mixed on one disc,
the audio compression files cannot be played back.Prepare a disc that includes compressed audio files
only.
The files are not named using characters that are
compliant with the specifications. Use the character codes and the number of
characters that are compliant with the specifications
for folder names and file names. In addition, always
use
“.MP3”, “.WMA”, “.mp3”or“.wma” for file
extensions.
It takes a long time before the music starts playing. The disc contains a large amount of data. Some time may be required to check the files. It is recommended that unnecessary folders or any files
other than compressed audio files should not be
recorded in a disc.
The sound quality is poor. The disc is dirty. Wipe off any dirt from the disc.
