Guide to the serial copy management system, Additional information, Applying the principle of human hearing – Sony DTC-A6 User Manual

Page 20: Noise-shaping filter, Continued)

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21

EN

Additional Information

3-856-761-11(2)

Guide to the Serial Copy
Management System

This deck uses the Serial Copy Management System,
which allows only first-generation digital copies to be
made of premastered software via the deck’s digital
input jack. An outline of this system appears below:

1 You can record from digital program sources (CDs,

premastered MDs or DATs) onto a DAT or recordable MD
via digital input jack on the DAT or MD deck. You
cannot, however, record from this recorded DAT or MD
onto another DAT or recordable MD via the digital input
jack on the DAT or MD deck.

CD player

DAT deck

MD deck

Optical cable or coaxial
digital connecting cable

Recording

DAT deck or

MD deck

v

First-generation
DAT or MD
recorded via
digital-to-digital
connection

v

Playing

Digital output jack

Digital input jack

DAT or MD

Digital output jack

Digital input jack

Recording

DAT deck or

MD deck

DAT deck or

MD deck

Playing

Optical cable or
coaxial digital
connecting cable

Audio connecting
cord

Line (analog) output jack

Line (analog) input jack

Applying the principle of human hearing

The SBM function applies the principle of human
hearing in the reintegration of signal information. The
auditory range of the human ear is generally
considered to be 20 Hz to 20 kHz; hearing sensitivity,
however, shows greater sensitivity to the range
between 3 kHz and 4 kHz, and lower sensitivity to
frequencies above and below this range. This principle
applies also to quantizing noise as well. By reducing
quantizing noise in this particular range, signals can be
recorded to produce more expansive sound than is
possible by a uniform reduction of noise over the entire
audible range.

Noise-shaping filter

The SBM function uses a noise-shaping filter (see Fig.
B) with a frequency response similar to that of the
human ear to reduce quantizing noise within the most
sensitive frequency range, and to feed back the
quantizing error (that is normally lost) back to the
input signal, re-integrating the low-end bit information
with the high-end bit information (see Fig. A).

Fig. A

24-bit information
input

Noise-shaping
filter

16-bit SBM
output

/

/

Fig. B shows the improvement in the quantizing noise
level when the SBM switch is on (theoretical values).
Given a noise level of 0 dB when the SBM switch is off,
the improvement in noise level for sampling
frequencies lower than 3 kHz exceeds 10 dB when the
SBM is activated.

Fig. B

SBM
ON

SBM
OFF

Noise
level
(dB)

Sampling frequency (Hz)

The SBM function operates only during recording. The
improved sound produced by the SBM function,
however, can be enjoyed during playback, regardless
of the SBM switch position or the DAT deck being
used.

-10

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0

5

10

15

20

25

20

100

50

200

1k

500

2k

15k

5k

10k

(Continued)

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