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ATRAC (Adaptive Transform Acoustic
Coding)
Within recordings, there are sounds which cannot be readily
heard. For example, as the volume decreases, high-pitched
sounds and low-pitched sounds become difficult to hear. Also, if
a quiet sound comes at the same time as or just after a loud
sound, it will not be heard. With minidiscs, data is compressed
using a technology called ATRAC (Adaptive Transform Acous-
tic Coding) which selectively chooses sounds based on human
sense of hearing characteristics. With this technology, the re-
corded data is about one-fifth the volume of the original data, al-
lowing it to fit on a compact minidisc.
0
+20
-20
-40
-60
(dB)
20
50
100
500
1k
5k
15k
10k
(Hz)
Sound skip guard memory
With the minidisc, the data of the track being played can be
temporarily stored up using a function called “sound skip
guard memory”. Even when data cannot be collected prop-
erly from the disc due to shaking or vibrations, information
is stored in the “sound skip guard memory”, so that there is
no break in the sound which is actually delivered.
UTOC (User Table Of Contents)
In a minidisc, apart from the recorded tracks, there is the
“UTOC”. In this area, information such as the position
where each track is recorded, the track divisions, and track
order are listed. When music search is done, the UTOC is
consulted, and the tracks are quickly found and played
back. When editing is done, only the UTOC is changed, so
there is no need to re-record the tracks.
Snap
»
Sensitivity of
our ears
«
Dull
Low
|
Sound range
\
High
Sound range and sensitivity of our ears
MD (Minidisc) Messages
Meaning/Action
A disc has been inserted with nothing recorded on it.
You have tried to join tracks which cannot be joined.
There is a problem (damage) with the disc.
(Replace the disc.)
There is not enough space left on the disc.
There are over 254 tracks.
The disc is in accidental erasure protection mode.
(Slide the accidental erasure protection tab so that the hole is covered.)
A malfunction occurred during recording.
(Stop the disc by pressing the
7
button and redo the operation.)
There is no disc in the unit.
You have tried to digitally dub a CD-ROM.
(Stop recording.)
You have tried to record or edit on a playback-only disc.
The track is protected. (This unit cannot undo track protection. Undo the pro-
tection using the appliance that created it.)
You have tried to make a copy of a copy by digital dubbing.
(Dub using analog input (LINE IN).)
The digital cable is disconnected.
The life of battery has ended.
The temperature of rechargeable battery is out of acceptable range.
Message
DIGITAL IN
UNLOCK
TRACK
PROTECTED
PLAYBACK DISC
NON AUDIO
CANNOT COPY
NO DISC
EMERGENCY STOP
DISC
PROTECTED
DISC ERROR
BLANK DISC
CANNOT JOIN
DISC FULL
SCMS
CANNOT COPY
BATT ERROR
HIGH TEMP
LOW TEMP
XM-R70(B)_P9-16.p65
6/23/99, 3:08 PM
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