Audio Information - Yamaha RX-V1500 Mode D'emploi

GLOSSARY

Audio information

ITU-R
ITU-R is the radio communication sector of the ITU
(International Telecommunication Union). ITU-R
recommends a standard speaker placement which is used
in many critical listening rooms, such as mastering
studios.
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 5/6 channels in Dolby Digital or
DTS 5.1/6.1-channel systems.
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.
96
THX Cinema processing
THX is an exclusive set of standards and technologies
established by the world-renowned film production
company, Lucasfilm Ltd. THX grew from George Lucas'
personal desire to make your experience of the film
soundtrack, in both movie theatres and in your home
theatre, as faithful as possible to what the director
intended.
Movie soundtracks are mixed in special movie theatres
called dubbing stages and are designed to be played back
in movie theatres with similar equipment and conditions.
This same soundtrack is then transferred directly onto
Laserdisc, VHS tape, DVD, etc., and is not changed for
playback in a small home theatre environment.
THX engineers developed patented technologies to
accurately translate the sound from the movie theatre
environment into the home, correcting the tonal and
spatial errors that occur. On this product, when the THX
indicator is on, THX features are automatically added in
Cinema modes (e.g. THX Cinema, THX Surround EX).
Adaptive decorrelation
In a movie theatre, a large number of surround speakers
help create an enveloping surround sound experience, but
in a home theatre there are usually only two speakers. This
can make the surround speakers sound like headphones
that lack spaciousness and envelopment. The surround
sounds will also collapse into the closest speaker as you
move away from the middle seating position. Adaptive
decorrelation slightly changes one surround channel's time
and phase relationship with respect to the other surround
channel. This expands the listening position and creates –
with only two speakers – the same spacious surround
experience as in a movie theatre.
Re-equalization
The tonal balance of a film soundtrack will be excessively
bright and harsh when played back over audio equipment
in the home because film soundtracks were designed to be
played back in large movie theatres using very different
professional equipment. Re-equalization restores the
correct tonal balance for watching a movie soundtrack in a
small home environment.
Timbre matching
The human ear changes our perception of sound
depending on the direction from which it is coming. In a
movie theatre, there is an array of surround speakers so
that the surround information is all around you. In a home
theatre, you use only two speakers located to the side of
your head. The timbre matching feature filters the
information going to the surround speakers so that they
more closely match the tonal characteristics of the sound
coming from the front speakers. This ensures seamless
panning between the front and surround speakers.