ROTEL 7.1 Surround Sound Receiver RSX-1067 - Manual (Page 20)

20 RSX-1067 Surround Sound Receiver
Dolby Digital
In 1992, a digital recording system, called
Dolby Digital, was first used in the film indus-
try. Dolby Digital is a recording/playback sys-
tem that uses compression techniques to store
large amounts of audio data efficiently, much
like the JPEG format stores large photographs
in small files on a computer. Because it is
capable of performance beyond that of au-
dio CDs and can tailor its output for a wide
ranges of system configurations, Dolby Digi-
tal is the standard audio format for DVDs and
for digital television broadcasting in the United
States.
The Dolby Digital system can be used to record
up to six discrete audio channels, but can also
be used for fewer. For example, a Dolby Digital
2.0 soundtrack is a digital 2-channel record-
ing of a matrix encoded Dolby Surround
soundtrack.. To play a Dolby Digital 2.0 re-
cording, use Dolby Pro Logic II decoding as
previously described.
The most common use of Dolby Digital in newer
films, in both the film industry and in home
theater, is Dolby Digital 5.1. Instead of encoding
multiple surround channels on a two-channel
recording, Dolby Digital 5.1 records six dis-
crete channels: front left, front center, front right,
surround left, surround right, and a Low Fre-
quency Effects (LFE) channel containing ultra-
low bass signals intended for a subwoofer.
A Dolby Digital decoder extracts the channels
from the digital bitstream, converts them to
analog signals and routes them to the appro-
priate amplifiers and speakers. All channels
provide full frequency response with total sepa-
ration between all channels and large dynamic
range capability. A Dolby Digital 5.1
soundtrack can provide more impressive sur-
round sound than matrix Dolby Surround.
Decoding of Dolby Digital 5.1 soundtracks is
automatic. When the RSX-1067 detects a Dolby
5.1 signal on one of its digital inputs, it acti-
vates the proper processing. Keep in mind that
Dolby Digital is only available from digital
sources (a DVD, a LaserDisc, or a Digital TV/
Cable/SAT tuner). Also, you must connect the
source with a digital cable (coax or optical)
to an active digital input on the RSX-1067.
NOTE
: Many DVDs have a Dolby Digital 2.0
matrix soundtrack as the default, which should
be decoded with Pro Logic II. The Dolby Digi-
tal 5.1 soundtrack may have to be selected
as an option from the setup menus at the be-
ginning of the DVD. Look for a Dolby Digital
5.1 selection under “Audio” or “Languages”
or “Setup Options” when you insert the disc.
DTS 5.1
DTS 96/24
DTS ® (Digital Theater Systems) is an alterna-
tive digital format competing with Dolby Digital
in both movie theaters and home theater
markets. The basic functions of the DTS sys-
tem are similar to those of Dolby Digital (for
example, 5.1 discrete channels), however the
technical details of the compression and de-
coding processes differ somewhat and a DTS
decoder is required.
A recent extension of the DTS encoding sys-
tem is DTS 96/24. These recordings provide
the performance of a 96kHz sampling rate
while still using actual 48kHz sampling rate
of standard DTS discs.
Like Dolby Digital, DTS can only be used on
a digital recording and, therefore, is only
available for home use on LaserDiscs, DVDs,
or other digital formats. To use the RSX-1067’s
DTS decoder, you must connect your DVD
player to the RSX-1067’s digital inputs.
As with Dolby Digital 5.1, detection and proper
decoding of DTS 5.1 signals is automatic.
NOTE : DVDs with a DTS soundtrack almost
always have it configured as an option to the
standard matrix Dolby Surround format. To
use DTS, you may have to go to the setup
menus at the beginning of the DVD and se-
lect “DTS 5.1” instead of “Dolby Surround”
or “Dolby Digital 5.1”. In addition, many DVD
players have the DTS digital bitstream turned
off by default and cannot output a DTS
soundtrack (even if selected on the disc’s
menu) until you activate the player’s DTS out-
put. If you hear no sound the first time you
attempt to play a DTS disc, go to the DVD
player’s configuration menus and turn on the
DTS bitstream. This is a one-time setting and
need only be done once.
DTS Neo:6
The RSX-1067 features a second type of DTS
surround sound decoding: DTS Neo:6. This
decoding system is similar to Dolby Pro Logic
II and is designed for playback of any 2-channel
stereo recording, either matrix-encoded or not.
The Neo:6 decoder can be used with any
conventional 2-channel source such a stereo
TV or FM broadcast or a CD. It can also be
used as an alternative method of decoding
matrix-encoded Dolby Surround recordings or
TV broadcasts. Activate the DTS Neo:6 de-
coding with the DTS Neo:6 button as detailed
later in this section. DTS Neo:6 is not used
with DTS 5.1 digital sources and the button
need not be pressed for those recordings.
Dolby Digital Surround EX
DTS-ES
6.1 and 7.1 Channel Surround
In 1999, the first Dolby Digital soundtrack was
released to theaters with an additional cen-
ter back surround channel, intended to increase
the directional effects from behind the audi-
ence. This additional surround channel is en-
coded into the two existing surround channels
in Dolby Digital 5.1, using a matrix encod-
ing process similar to that used previously in
Dolby Surround. This new extended surround
capability is called Dolby Digital Surround EX.
DTS has added a similar capability for record-
ing this extended surround information called
DTS-ES
® 6.1 Matrix. They have also taken it
one step further and developed the capabil-
ity to record this extended surround informa-
tion as a discrete channel in a system called
DTS-ES
® 6.1 Discrete.
All of these systems are extensions of the ex-
isting Dolby Digital 5.1 and DTS 5.1 digital
surround sound formats. Users with one cen-
ter back speaker (a 6.1 configuration) or two
center back speakers (a 7.1 configuration) can
take advantage of this extended surround in-
formation. On traditional 5.1 channel systems,
Dolby Digital Surround EX or DTS-ES 6.1 discs
sound exactly the same as 5.1 channel discs
in each respective format.
If you have configured your system with one
or two center back speakers, decoding of
DTS-ES discs is automatic, just as it is with stan-
dard DTS soundtracks. Likewise, decoding of
Dolby Digital Surround EX discs is automatic
with one exception. Some Surround EX titles
do not have the detection “flag” encoded on