Arcam AVR surround amplifier / AV processor AVR600 - Manual (Page 50)

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Dolby volume
Dolby Volume is a sophisticated new
technology that resolves the problem of
different volume levels between programme content
(e.g. a TV show and advert breaks) and between sources
(e.g. a rock radio station and DVD, or between two
TV stations). It lets the listener enjoy everything at the
same preferred listening level without having to reach
for the volume control to compensate for the different
recording/output levels. This is the Volume Leveller
function of Dolby Volume.
Dolby Volume also works in conjunction with the
AVR500, AVR600 or AV888 volume control setting to
compensate for the ear’s changing sensitivity at different
frequencies depending on how loud the audio is. It
is based on a model of how human hearing works. It
properly balances low, mid and high frequencies to
maintain all the nuances and impact of the original
audio regardless of the actual selected playback volume
level. This is the Volume Modeller function of Dolby
Volume.
Dolby Volume measures, analyses and maintains volume
levels based on how people perceive sound. A variety of
audio parameters are monitored including spectral- and
time-based loudness to ensure that perceived dynamics,
timbre and bass performance remain consistent at all
volume levels.
Dolby Volume also lets the listener control a
programme’s dynamic range – the range between loud
and quiet sounds. For example, with the volume turned
down for late-night viewing, dynamic range can be
adjusted so that speech remains clear and loud effects or
music passages retain their impact without waking up
the family.
Settings
Dolby Volume can be applied to any analogue or digital
stereo source or any digital multichannel source. It
is not available in Stereo Direct or on the analogue
multichannel input. Dolby Volume can even be applied
to processing of stereo signals (e.g. PLII Music) or when
down-mixing a digital multichannel source (e.g. Dolby
Digital 5.1 down to stereo).
Dolby Volume can be enabled and configured separately
for each audio input in the Input Config menu. The
default is Off for ‘audiophile’ listening to analogue or
digital stereo sources, however you may wish to enable
Dolby Volume on some or all inputs to maintain the
same perceived overall listening level between sources
and frequency response regardless of the volume setting.
There are two modes for Dolby Volume: ‘Cinema’ and
‘Music’, which calibrate the system to match the type of
audio material generally played on each input. Movie
should be selected for sources which typically play
movie soundtracks. Music should be selected for all
other sources (CD, TV, Satellite, Tuner, etc.). Most of the
controlling parameters of Dolby Volume are automatic
as they are dependent on analysis of the audio signal and
the volume setting of the AVR500, AVR600 or AV888.
However, the Volume Leveller and Calibration Offset
controls (see below) can be adjusted to your preference.
Volume Leveller
The Volume Leveller function of Dolby Volume controls
how closely quiet and loud sources and programme
content are matched to each other, based on the
ear’s perception of loudness. The range of values is 0
(minimal levelling) to 10 (maximum levelling). The
default setting is 9. If the Volume Leveller function
is turned off, no level matching between sources and
programme material is performed. This is not the
same as turning Dolby Volume off as volume related
frequency response processing is still active.
When Dolby Volume is being applied to the current
input, a Dolby Volume processing mode indicator is
shown on the OSD and the front panel display.
Calibration offset
The Calibration Offset parameter of Dolby Volume
allows you to compensate for speaker efficiencies and
listening position – effectively moving the reference
listening level up or down the volume scale. The default
value is 0 and this should normally produce a good
result when the speaker levels are set using a sound
pressure level meter at the listening position (75dB SPL,
‘C’ weighting, slow response).