104
En
GLOSSARY
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LFE 0.1 channel
This channel reproduces low-frequency signals. The
frequency range of this channel is from 20 Hz to 120 Hz.
This channel is counted as 0.1 because it only enforces a
low-frequency range compared to the full-range
reproduced by the other 5/6 channels in Dolby Digital or
DTS 5.1/6.1-channel systems.
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MP3
One of the audio compression methods used by MPEG. It
employs the irreversible compression method, which
achieves a high compression rate by thinning out the data
of hardly audible part to the human ears. It is said to be
capable of compressing the data quantity by about 1/11
(128 kbps) while maintaining a similar audio quality to
music CD.
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Neo:6
Neo:6 decodes the conventional 2-channel sources for 6-
channel playback by the specific decoder. It enables
playback with the full-range channels with higher
separation just like digital discrete signal playback. There
are two modes available: “Music mode” for music sources
and “Cinema mode” for movie sources.
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PCM (Linear PCM)
Linear PCM is a signal format under which an analog
audio signal is digitized, recorded and transmitted without
using any compression. This is used as a method of
recording CDs and DVD audio. The PCM system uses a
technique for sampling the size of the analog signal per
very small unit of time. Standing for “Pulse Code
Modulation”, the analog signal is encoded as pulses and
then modulated for recording.
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Sampling frequency and number of
quantized bits
When digitizing an analog audio signal, the number of
times the signal is sampled per second is called the
sampling frequency, while the degree of fineness when
converting the sound level into a numeric value is called
the number of quantized bits. The range of rates that can
be played back is determined based on the sampling rate,
while the dynamic range representing the sound level
difference is determined by the number of quantized bits.
In principle, the higher the sampling frequency, the wider
the range of frequencies that can be played back, and the
higher the number of quantized bits, the more finely the
sound level can be reproduced.
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WAV
Windows standard audio file format, which defines the
method of recording the digital data obtained by
converting audio signals. It does not specify the
compression (coding) method so a desired compression
method can be used with it. By default, it is compatible
with the PCM method (no compression) and some
compression methods including the ADPCM method.
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WMA
An audio compression method developed by Microsoft
Corporation. It employs the irreversible compression
method, which achieves a high compression rate by
thinning out the data of hardly audible part to the human
ears. It is said to be capable of compressing the data
quantity by about 1/22 (64 kbps) while maintaining a
similar audio quality to music CD.
