Dsp effects modes, About thx, Cinema processing – Arcam AV8 PReamp Processor E-2 User Manual

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THX Surround EX and Surround ES
Surround EX is a joint development of Dolby Laboratories and the
THX division of Lucasfilm Ltd. In a movie theatre, film soundtracks
that have been encoded with Surround EX technology are able to
reproduce an extra channel which has been added during the mixing
of the programme. This channel, called surround back, places sounds
behind the listener in addition to the front left, centre, front right,
surround left, surround right and LFE channels. This additional channel
provides the opportunity for more detailed imaging behind the listener
and brings more depth, spacious ambience and sound localization
than with simple 5.1 reproduction. Movies that were created using
the Surround EX technology, when released into the home consumer
market may exhibit wording to that effect on the packaging.
With appropriate material, the THX Surround EX mode will normally
activate automatically, providing this option has been enabled in the
‘THX Settings’ page of the Setup Menu. Some Dolby Digital Surround
EX soundtracks are missing the digital flag that allows automatic
switching. If you know that the movie that you are watching is encoded
in Surround EX, you can select the THX Surround EX playback mode
manually.
You can also switch on the THX Surround EX mode during the
playback of 5.1 channel material that is

not Surround EX encoded.

In such case the information delivered to the surround back channels
will be programme-dependent and may or may not be very pleasing
depending on the particular soundtrack and the tastes of the individual
listener.
THX MusicMode
For the replay of multichannel music the THX MusicMode can be
selected. In this mode THX ASA processing is applied to the surround
channels of all 5.1 encoded music sources such as DTS and Dolby
Digital to provide a wide stable rear soundstage.

DSP EFFECTS MODES

The AV8 has a number of effects modes that can be used to enhance
a stereo signal and to make use of the surround loudspeakers. DSP
effects modes are only available with stereo source signals.
You can listen to the influence of any effect mode by playing a CD, then
pressing pause, when the decaying reverberation effect can be heard.
Available effects modes
Music: Music surround makes full use of the additional speakers placed
at the centre, sides and rear of the room. This effect uses ambiance
extraction for the side and rear speakers and offers the most subtle
surround processing with no reverberation or reflections.
Party: The Party effect allows unprocessed stereo signals to be played
over all speakers for background music or for maximum acoustical
output of the system.
Club: The Club effect generates reflections and short reverberation
information to the front, side and rear speakers. It simulates a small club
venue, such as a Jazz Club.
Concert Hall: The Concert Hall effect generates the ambient
information for the simulation of a medium size hall. Reflections and
medium length reverberation information are sent to all channels.
Sports: Sports stadium effect is ideal for use when watching live sports
events which would normally be in stereo. The open ambience of a
sports stadium is actively recreated around you, except from the centre
channel which is kept clear for commentary.
Church: The Church effect uses a reverberation algorithm which
emphasises rich, smooth reverberant decay in large spaces. As its name
suggests, it works well for simulating a space with long reverberation
time relative to its size, such as a large church or cathedral.

ABOUT THX

CINEMA PROCESSING

THX TECHNOLOGY

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 a sound depending on the
direction from which the sound 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 there are usually only two speakers
located at either 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.
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. Two surround speakers can 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.
ASA (Advanced Speaker Array)

™

ASA is a proprietary THX technology which processes the sound
fed to two surround and two surround back speakers to provide the
optimal surround sound experience. ASA is used in two modes; THX
Ultra2 Cinema and THX MusicMode.

THX STANDARDS

Lucasfilm define a series of technical performance standards that
equipment must exceed before it is awarded THX certification. Several
levels of performance standards are defined, the most demanding
standards are set for THX Ultra2. THX Ultra2 requirements cover
every aspect of the product including pre-amplifier performance and
operation, video pass through, and hundreds of other parameters in
both the digital and analogue domain.
Before any home theatre component can be THX Ultra2 certified,
it must incorporate all the technology features above and also pass
this rigorous series of quality and performance tests. Only then can a
product feature the THX Ultra2 logo, which is your guarantee that the
home cinema products you purchase will give you superb performance
for many years to come.
A list of available DVD software titles encoded with Dolby Digital
Surround EX technology can be found at