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ADVANCED FUNCTIONS
Much of the AVR 254’s performance is handled automatically, with little
intervention required on your part. However, the AVR 254 is a sophisti-
cated component, and is capable of being customized to suit your
particular system and your tastes. In this section we describe some of
the more advanced adjustments available on the AVR 254. You may
return to this section later, when you have become more familiar with
your receiver.
Audio Processing and Surround Sound
Audio signals output by sources are encoded in a variety of formats that
can affect not only the quality of the sound but the number of speaker
channels and the surround mode. You may also manually select a
different surround mode, although for certain types of audio signals,
the modes available will be limited in certain ways, as described below.
Analog Audio Signals
Analog audio signals usually consist of two channels – left and right.
The AVR 254 offers three basic options for playback of analog audio:
1.
Analog Bypass Mode: In this mode, the 2-channel signal is passed
directly from the input to the volume control, without being digitized
or undergoing any processing for bass management or surround
sound. The requirements for selecting analog bypass mode are:
a) The analog audio inputs for the source must be selected. If neces-
sary, press the Info Button on the remote and use the
⁄
/
¤
Buttons to scroll to the Audio Source setting, then select an
analog input.
b) The tone controls must be disabled by setting Tone Control to Off.
Press the Audio Effects Button to access the Tone Control setting
in the Audio Effects submenu.
c) The 2-channel Stereo mode must be selected. Press the Surround
Modes Button to access the STEREO line of the Surround Modes
submenu.
When the Tone Control setting is Off, the front speakers will be set to
Large automatically, as indicated by the double boxes in their positions
in the Speaker/Channel Input Indicators on the front panel. That indi-
cates that Analog Bypass mode is active. When the Tone Control setting
is turned On, if you have set the front speaker crossover to a numeric
setting, the front speakers will return to the Small setting, as indicated by
single boxes in the Speaker/Channel Input Indicators. When the front
speakers are Small and 2-Channel Stereo mode has been selected in
the Surround Modes submenu, DSP Surround Off mode is active.
2.
DSP Surround Off Mode: The DSP Surround Off mode digitizes the
incoming signal and applies the bass management settings, including
speaker configuration, delay times and output levels. This mode is
desirable when your front speakers are small, limited-range satellites
and you are using a subwoofer. To select this mode, use a digital
audio input, or turn the Tone Control setting off.
3.
Analog Surround Modes: One of the main benefits of a surround
receiver such as the AVR 254 is its ability to process 2-channel
audio signals to produce multichannel surround sound in a variety
of modes, even when no surround sound has been encoded in the
recording. Among the available modes are the Dolby Pro Logic II/IIx
modes, the Dolby Virtual Speaker modes, the DTS Neo:6 modes, the
Logic 7 modes, and the Stereo modes.
Digital Audio Signals
Digital audio signals offer the benefit of greater capacity, which allows
recording artists to encode center and surround channel information
directly into the signal. The result is improved sound quality and startling
directionality, since each of these channels is reproduced discretely.
Alternatively, the artist may encode only two channels, but the digital
signal allows for a higher sampling rate that delivers greater detail.
High-resolution recordings usually sound extraordinarily distortion-free
at all frequencies, but especially at high frequencies.
Multichannel digital recordings usually are found in the 5.1-, 6.1- or
7.1-channel formats. The channels included in a 5.1-channel recording
are front left, front right, center, surround left, surround right and LFE.
The LFE channel is denoted as “.1” to represent the fact that it is not
full-range, being limited to the low frequencies.
6.1-Channel recordings add a single surround back channel, and
7.1-channel recordings add surround back left and surround back
right channels to the 5.1-channel configuration. New formats, such
as Dolby TrueHD, Dolby Digital Plus, DTS-HD and DTS-HD Master
Audio, are available in 7.1-channel configurations. The AVR 254 is
able to play the new audio formats, delivering a more exciting home
theater experience.
NOTE: To use the 6.1- and 7.1-channel surround modes, the
AVR 254 must be configured so that the Surround Back channels
are enabled. See the Manual Setup section on page 46 of the
Advanced Functions section for more information.
Digital formats include Dolby Digital 2.0 (two channels only), Dolby
Digital 5.1, Dolby Digital EX, Dolby Digital Plus, Dolby TrueHD, DTS-HD,
DTS-HD Master Audio, DTS 5.1, DTS-ES (6.1 Matrix and Discrete),
DTS 96/24, 2-channel PCM modes in 32kHz, 44.1kHz, 48kHz
or 96kHz, and 5.1 or 7.1 multichannel PCM.
When a digital signal is received, the AVR 254 detects the encoding
method and the number of channels. The number of channels encoded
will appear briefly in the front-panel display as three numbers, separated
by slashes (e.g., “3/2/.1”).
The first number indicates the number of front channels in the signal:
“1” represents a monophonic recording, usually an older program that
has been digitally remastered or, more rarely, a modern program
for which the director has chosen a special effect.
“2” indicates the presence of the left and right channels, but no
center channel.
“3” indicates that all three front channels (left, right and center)
are present.
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