Audio Power DSP System Multiface Manual De Usuario

User's Guide HDSP System Multiface II

12.2 DVD-Playback (AC-3/DTS) under MME

AC-3 / DTS
When using popular DVD software player like WinDVD and PowerDVD, their audio data stream
can be sent to any AC-3/DTS capable receiver, using the Hammerfall DSP's SPDIF output. For
this to work the SPDIF output wave device has to be selected in >Control Panel/ Sounds and
Multimedia/ Audio<. Also check 'use preferred device only'.

You will notice that the DVD software's audio properties now allow to use 'SPDIF Out', 'Use
SPDIF' or to 'activate SPDIF output'. When selecting these, the software will transfer the non-
decoded digital multichannel data stream to the Hammerfall DSP.

This 'SPDIF' signal sounds like chopped noise at highest level. Therefore the Multiface auto-
matically activates the non-audio bit within the digital data stream, to prevent most SPDIF re-
ceivers from accepting the signal, and to prevent any attached equipment from being damaged.

Multichannel
PowerDVD can also operate as software decoder, sending a DVD's multichannel data stream
directly to the analog outputs of the Multiface. Supported are all modes, from 2 to 8 channels, at
16 bit resolution and 48 kHz sample rate. Playback via the ADAT output of the Multiface is also
supported.

For this to work the option Interleaved has to be activated in the Settings dialog, an output wave
device of the HDSP has to be selected in >Control Panel/ Sounds and Audio Devices/ Audio<,
and 'Use only default devices' has to be checked. Additionally the loudspeaker setup, found
under >Volume/ Speaker Settings/ Advanced< has to be changed from Stereo to 5.1 Surround.

PowerDVD's and WinDVD's audio properties now list several multichannel modes. If one of
these is selected, the software sends the decoded analog multichannel data to the HDSP.

The device selected as Default Sound playback device defines the first playback channel. Note
that this device can not be chosen freely. An interleaved playback with more than 2 channels
can only be done in blocks of eight channels. Therefore the starting device has to be channel
1/2 or 9/10.

The typical channel assignment for surround playback is:

1 (first chosen playback channel) - Left
2 - Right
3 - Center
4 - LFE (Low Frequency Effects)
5 - SR (Surround Right)
6 - SL (Surround Left)

Note 1: Setting the card to be used as system playback device is against common sense, as
professional cards are not specialized to play back system sounds, and shouldn't be disturbed
by system events. To prevent this, be sure to re-assign this setting after usage, or to disable
any system sounds (tab Sounds, scheme 'No audio').

Note 2: The DVD player will be synced backwards from the HDSP card. This means when us-
ing AutoSync and/or word clock, the playback speed and pitch follows the incoming clock sig-
nal.