Harman Kardon AVR 645 Service Manual Download Page 24

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OPERATION

playback, as well as move to the next track. Activity of
the Transport buttons may vary from one media player
to another, but at the very least you will be able to use
the Play and Stop buttons.

Once playback is started, the audio from a USB source
is treated the same as any other two-channel audio
source, and you may apply any of the appropriate
surround processing modes. When playing back audio
from a computer via the USB connection, the internal
speakers in a laptop computer are often muted.

Speaker/Channel Indicators

In addition to the bitstream indicators, the AVR 645
features a set of unique channel-input indicators that
tell you how many channels of digital information are
being received and/or whether the digital signal is
interrupted (Figure 23).

Figure 23

The letters inside the boxes tell you which channels
are receiving an input signal. Since conventional ana-
log audio is only two channels, the “L” and “R” letters
will light with any analog source. When a digital source
is in use, you will see letters displayed that correspond
to the number of channels in the incoming data
stream, which may be just the L and R for two-chan-
nel PCM or 2.0 Dolby Digital material. When a 5.1
signal is being received, the L/C/R/SL/SR indicators
will light, with the LFE indication also being shown
when an LFE signal is present. All seven indicators,
including the SBL/SBR letters, will light for a 7.1 sig-
nal, and a horizontal line is shown to connect the
SBL/SBR indicators when a 6.1 source is in use.

It is important to note that although Dolby Digital, for
example, is referred to as a “5.1” system, not all Dolby
Digital DVDs or programs are encoded for 5.1. Thus,
it is sometimes normal for a DVD with a Dolby Digital
soundtrack to trigger only the “L” and “R” indicators.

NOTE:

Many DVD discs are recorded with both “5.1”

and “2.0” versions of the same soundtrack. When
playing a DVD, always be certain to check the type of
material on the disc. Most discs show this information
in the form of a listing or icon on the back of the disc
jacket. When a disc does offer multiple soundtrack
choices, you may have to make some adjustments to
your DVD player (usually with the “Audio Select” button
or in a menu screen on the disc) to send a full 5.1
feed to the AVR 645. It is also possible for the type of
signal feed to change during the course of a DVD’s

playback. In some cases, the previews of special
material will only be recorded in 2.0 audio, while the
main feature is available in 5.1 audio. The AVR 645
will automatically sense changes to the bitstream and
channel count and reflect them in these indicators.

The letters used by the

Speaker/Channel Input

Indicators

will flash to indicate when a bitstream

has been interrupted. This will happen when a digital
input source is selected before the playback starts, or
when a digital source such as a DVD is paused. The
flashing indicators remind you that the playback has
stopped due to the absence of a digital signal and not
through any fault of the AVR 645. This is normal, and
the digital playback will resume once the playback is
started again.

The boxes around the channel indication letters are
used to show which speakers are configured in your
system. A small box around the letter indicates that a
“Small” speaker has been assigned to that position,
while a larger, double box indicates a “Large” speaker
assignment.

Note that in some cases, such as an analog stereo or
2.0 digital sources you will see empty speaker posi-
tion boxes, which indicates that the speaker is active
and will receive sound, but that there is no discrete
signal for that channel. In other cases you may see
letters with no speaker boxes. This indicates that there
is a discrete signal for that channel, but due to the
mode in use (e.g., Dolby VS with a 5.1 source) there
is no signal being sent to the channel.

Night Mode

A special feature of Dolby Digital is the Night mode,
which enables specially encoded Dolby Digital input
sources to be played back with full digital intelligibility
while reducing the minimum peak level by 1/4 to 1/3.
This prevents abruptly loud transitions from disturbing
others, without reducing the impact of the digital
source. The Night mode is available only when Dolby
Digital signals with special data are being played.

The Night mode may be engaged at any time when
a Dolby Digital source is playing by pressing the

Night

Mode Button

. Each press of the button will

change the Night mode setting, as shown in the lower
third of the on-screen display (except when 720p or
1080i sources are in use). To turn the Night mode off,
press the button as described, until

D-RANGE

OFF

is shown.

The Night mode may also be selected to always be on
at either level of compression using the options in the

DOLBY SURROUND

menu. See page 27 for

information on using the menus to set this option.

IMPORTANT NOTES ON DIGITAL PLAYBACK:

• When playing DVDs, please note that even when you

have selected a specific digital audio format for play-
back, an individual disc may change formats or the

number of available channels during playback. For
example, even if you select a DTS mode for the movie,
you may see Dolby Digital in use when the trailers,
menus or copyright warnings are playing. This is not a
fault with either the AVR or your DVD player, as both
are responding to the way the disc was created.

• When viewing digital television signals, note that the

number of audio channels available may vary during
the course of a program, depending on the content.
For example, while a sports event may have 5.1
sound, the commercials or local station content may
be in 2.0. In addition, not all local stations are currently
equipped for carrying the 5.1 digital audio signals. This
may mean that even though the actual program is
produced with 5.1, it may be transmitted in a 2.0
configuration in some areas. Your AVR will automatically
change to react to the proper type of audio stream if it
is changed by the broadcast station.

• Although the AVR 645 will decode virtually all current

DVD movies, CDs and HDTV sources, it is possible
that some future digital sources may not be compati-
ble with the AVR 645.

• Not all digitally encoded programs contain full 5.1-

or 6.1-channel audio. Consult the program guide
that accompanies the DVD or laser disc to deter-
mine which type of audio has been recorded on the
disc. The AVR 645 will automatically sense the type
of digital surround encoding used and adjust to
accommodate it.

• When a digital source is playing, you may not be

able to select some of the analog surround modes
such as Dolby Pro Logic II, Dolby Pro Logic IIx,
Stereo, Hall, Theater or Logic 7.

• When a Dolby Digital or DTS source is playing,

it is not possible to make an analog recording using
the

Tape Outputs

and

Video 1 Audio Outputs

. However, the digital signals will be passed

through to the

Digital Audio Outputs

Using

The AVR 645 is equipped for use with Harman Kardon’s
optional

iPod docking station.

When The Bridge is connected to the AVR and an
iPod properly docked, you may use either remote to
control the iPod for audio playback while using the
front-panel display and on-screen semi-OSD mes-
sages to help you locate tracks or view information
about the track being played. In addition, connecting
an iPod to the AVR 645 through The Bridge also
charges the iPod’s battery. Using the

DMP AUTO

POWER

menu option, as described on page 45,

you may even have the AVR 645 automatically turn
on with your iPod as a playback source whenever
the iPod is turned on.

The

Bridge

The

Bridge

LFE

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