User’s Guide
22
L
ISTENING TO
M
ULTI
-C
HANNEL
A
UDIO WITH
D
OLBY
®
D
IGITAL
L
IVE
The Dolby Digital Live feature encodes multi-channel audio from PC games and other 3D digital audio
sources into a 5.1 Dolby Digital signal that can be transmitted to an external digital speaker system or A/V
receiver with a Dolby Decoder. This enables you to play 3D audio on the same system used for playing
DVD audio.
Without the Digital Dolby feature, the 3D sounds played on your PC cannot be connected to a digital
speaker or home theater system. Instead, they must be connected via the Montego DDL’s analog multi-
channel outputs. With Dolby Digital Live, the PC audio and Dolby Digital audio signals for DVD playback
can both be played on the same digital input of your A/V receiver or digital speakers. Thus, rather than use a
set of analog connections for PC audio and a digital connection for DVD audio, the Dolby Digital Live
feature lets you use one simple digital audio connection for both DVD and PC audio multi-channel sound.
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When the Dolby Digital Live feature is enabled, via the S/PDIF Settings pull-down menu, the analog
speaker outputs are disabled.
L
ISTENING TO
3D
G
AME
A
UDIO
When playing games that use EAX2®, A3D1® or DirectSound3D™, the Montego DDL surround sound
processor converts the 3D positional sounds into HRTF positional audio so that the 3D effects of the game
can be heard in headphones or stereo speakers.
When using Dolby Digital Live to drive digital speakers via the S/PDIF output, the 3D positional audio
from the game will be converted to 5.1 positional audio on the speakers, to create a realistic and immersive
gaming experience.
U
SING
DDL
M
ODES IN
V
ISTA
Due to changes in the way the hardware works in Vista, there are now 2 DDL modes to choose from -
"DDL 5.1 Encoding" and "DDL Stereo Encoding". The end result of both modes is the same – encoded
5.1 Dolby Digital Live output from the S/PDIF output. The use for each depends on what type of audio is
being played.
In XP/2000, when DDL mode is selected, stereo audio is “upmixed” so that it is sent to all speakers (not
just the Front Left and Right), and 5.1 audio is encoded “intact” into a Dolby Digital stream. Under Vista,
the “upmixing” required the creation of the new "DDL Stereo Encoding" setting – this is what should be
used to allow stereo sources to be pushed out in DDL mode to all 6 channels of a 5.1 system. For audio
sources that have discrete multi-channel audio (such as most popular PC games), the "DDL 5.1 Encoding"
setting should be chosen to ensure that the placement of each of the 6 audio channels is correct in the
encoded DDL output.
NOTE:
When DDL modes are used, the Windows Vista Playback Devices windows should have
“Speakers” (not “Digital Output”) selected as the default Playback Device, even though the
S/PDIF connection is being used.