Advanced Features
3. Subtract the distance to the
surround speakers from the distance
to the front speakers.
a. When setting the delay time for
the Dolby Digital surround mode,
the optimal delay time is the result-
ing figure. For example, if the front
speakers are ten feet away and the
surround speakers are five feet
away, the optimal delay time is
figured as 10-5=5. Thus, in this
example, the delay should be set at
five milliseconds.
b. When setting the delay time for
an analog surround mode (Pro
Logic, Hall, Movie or Matrix) take
the result of the subtraction and
add 15 to obtain the optimal delay
time. For example, if the front
speakers are ten feet away and the
surround speakers are five feet
away, the optimal delay time is
figured as 10-5+15=20. Thus in
this example, the delay should be
set at twenty milliseconds.
The Dolby Digital mode also provides a
separate setting for the center channel
delay mode, since the discrete nature
of Dolby Digital signals makes the
location of the center channel speaker
more critical. To set the delay for the
center channel, measure the distance
from the preferred listening position in
the center of the room to both the center
channel speaker and either the left or
right speaker.
If the distances are equal no further
adjustment is required and the center
delay should be set to zero. If the distance
to the front speakers is greater than the
distance to the center speaker you may
wish to reposition the speakers by mov-
ing the front left/right speakers closer
to the listening position or the center
speaker further away from the listening
position.
If repositioning of the speakers is not
possible, adjust the center delay time
so that you add one millisecond of center
channel delay for each foot that the dis-
tance to the center speaker lags behind
the front speakers. For example, if the
front left/right speakers are each 10 feet
from the listening position and the
center channel speaker is 8 feet away, the
delay is figured as 10-8=2, suggesting an
optimal center delay of 2 milliseconds.
The factory settings for the delay times
are shown in the chart on page 31. If the
use of the formulas described above or
your own experimentation and prefer-
ences suggest that the delay time be
changed, the adjustment is made from
the SURROUND MODE menu.
Reach the menu by pressing Select j
and then pressing the ¤ button i
once so that the on-screen cursor >is
next to the SURROUND MODE line and
then press Select again. The SUR-
ROUND MODE menu (see figure #15)
will then appear. If you wish to change
the surround mode before proceeding,
use the ‹ or › buttons i until the
desired mode is highlighted in reverse
video. Next press the ¤ button so that
the cursor is next to CENTER CH or
SURROUND CH. (Note that center
channel delay may only be adjusted in
Dolby Digital mode.) Press the › button
i until the desired time is highlighted
in reverse video and then press ¤ until
the cursor is next to RETURN TO
MAIN MENU and press Select j.
Other adjustments may now be made, or
move the cursor to MENU OFF and
press Select to exit the menu system.
Digital Audio Playback
Dolby Digital
Dolby Digital (also known as AC-3) is the
latest advancement in surround sound
technology, delivering up to five full-
range surround channels (left, center,
right, left surround and right surround)
plus a special dedicated Low-Frequency
Effects (LFE) channel. This represents a
major advancement over traditional
analog surround in that each surround
channel is fully discrete and capable of
full bandwidth reproduction. Dolby
Digital is available on DVD and LV discs,
and it will be a part of the new high
definition television (HDTV) system
when digital broadcasting begins in
1998. Dolby Digital for the home is based
on the same system used to deliver digital
audio sound tracks in movie theaters,
enabling true cinema reproduction in
your home.
To utilize the Dolby Digital mode you
must have a digital source properly
connected to the AVR85. The RF digital
output of a laser disc player should be
connected to the AC-3 RF jack a on
the rear panel. Note that this jack is for
use only with the RF output from an LV
player and should not be connected to
any other audio, video or digital device.
Digital datastream outputs from DVD
players, HDTV receivers and CD players
should be connected to the AC-3/PCM
Optical or Coaxial inputs on the rear
panel °·. In order to provide a back-
up signal and a source for recording,
the analog outputs provided on digital
source equipment should also be con-
nected to their appropriate inputs on the
AVR85 rear panel. (e.g., connect the
analog stereo audio output from a DVD
to the DVD inputs • on the rear panel
when you connect the digital outputs).
When playing back a digital source, first
select the input using the remote or front
panel controls d48)!. Next
select the digital source by pressing the
appropriate Digital Input button
9g. When the digital source is play-
ing, the AVR85 will automatically detect
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