JVC XM-R70 manual MD Minidisc Messages, Atrac Adaptive Transform Acoustic Coding

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.

(dB)

+20

Snap 0

»

Sensitivity of -20our ears

«-40

Dull

-60

20	50	100	500	1k	5k	10k	15k
							(Hz)

Low Sound range \ High

Sound range and sensitivity of our ears

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.

MD (Minidisc) Messages

Message

BLANK DISC

CANNOT JOIN

DISC ERROR

DISC FULL

DISC

PROTECTED

EMERGENCY STOP

NO DISC

NON AUDIO

CANNOT COPY

PLAYBACK DISC

TRACK

PROTECTED

SCMS

CANNOT COPY

DIGITAL IN

UNLOCK

BATT ERROR

HIGH TEMP

LOW TEMP

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 7button 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.

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