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GLOSSARY
Bitstream
This is the digital form of multiple channel audio data
(eg., 5.1 channel) before it is decoded into its various
channels.
CINEMA DSP
Since the Dolby Surround and DTS systems were
originally designed for use in movie theaters, their effect
is best felt in a theater having many speakers and
designed for acoustic effects. Since home conditions,
such as room size, wall material, number of speakers, and
so on, can differ so widely, it’s inevitable that there are
differences in the sound heard as well. Based on a wealth
of actually measured data, YAMAHA CINEMA DSP uses
YAMAHA original sound field technology to combine
Dolby Pro Logic, Dolby Digital and DTS systems to
provide the visual and audio experience of movie theater
in the listening room of your own home.
Decoder
A decoder restores the coded signals on DVDs to normal.
This is called decoding.
Dolby Digital
This is a method of coding digital signals developed by
Dolby Laboratories. Apart from stereo (2-channel) audio,
these signals can also be 5.1-channel audio. A large
amount of audio information can be recorded on one disc
using this method.
Dolby Pro Logic
A surround system where a 4-channel audio track is
recorded as 2 channels and then is restored to 4 channels
for play. The surround channel is monaural and can
reproduce up to 7 kHz.
Dolby Pro Logic II
Dolby Pro Logic II is an improved technique used to
decode vast numbers of existing Dolby Surround
software. This new technology enables a discrete 5-
channel playback with 2 front channels, 1 center channel,
and 2 rear channels (instead of only 1 rear channel for
conventional Pro Logic technology). A music mode is
also available for 2-channel sources in addition to the
movie mode.
DTS (Digital Theater Systems)
This surround system is used in many movie theaters
around the world. There is good separation between the
channels, so realistic sound effects are possible.
Dynamic range
Dynamic range is the difference between the lowest level
of sound that can be heard above the noise of the
equipment and the highest level of sound before distortion
occurs.
LFE 0.1 channel
This channel is for the reproduction of low bass signals.
The frequency range for this channel is 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 channels in a Dolby Digital or
DTS 5.1 channel systems.
Linear PCM (pulse code modulation)
PCM is the usual digital method used for music CDs.
DVDs have a greater volume so they use linear PCM,
which has a higher sampling rate. Compressed PCM
signals are called packed PCM (PPCM).
Matrix 6.1
The system incorporates Matrix 6.1 decoder for Dolby
Digital and DTS multi-channel software that enables 6.1-
channel reproduction by adding the rear center channel to
existing 5.1-channel format. (The rear center channel is
created from rear left and right channels, and outputted
from virtual rear center speaker.) With this additional
channel, you can experience more dynamic and realistic
moving sound especially with scenes with “fly-over” and
“fly-around” effects.
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.
SILENT CINEMA
YAMAHA has developed a natural, realistic sound effect
DSP algorithm for headphones.
Parameters for headphones have been set for each sound
field so that accurate representations of all the sound field
programs can be enjoyed using headphones.
Virtual CINEMA DSP
YAMAHA has developed a virtual CINEMA DSP
algorithm that allows you to enjoy DSP sound field
surround effects even without center or rear speakers by
using virtual rear speakers.
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