SDP-3 Digital Surround Processor/Controller
PCM Effects and Parameters
45
AC-3 Effects are compatible with Dolby Digital input signals. Any AC-3-
capable software and/or source components should be labeled with a
Dolby Digital badge, similar to the one on the SDP-3 front panel.
AC-3 Status Display
In the AC-3 effects, an AC-3 Status Display is available in the parameter
menu with the following information.
MATRIX ENCODED: YES indicates a 2.0 Dolby Digital input is matrix
encoded; No indicates it is not.
DOWNMIX: YES indicates a Dolby Digital input is being downmixed for
the selected speaker configuration. NO indicates no downmixing is
taking place, except in the 5.1 2-Channel Effect, which is designed to
create a two-channel downmix from Dolby Digital 5.1 channel signals.
DATA RATE: 32-640kb, depending on the data rate of the incoming
Dolby Digital signal.
SAMPLE RATE: 44.1kHz or 48kHz depending on the incoming Dolby
Digital signal.
PGM CONTENT: shows you the actual spatial characteristics of the
incoming soundtrack. The information appears as F/S.LFE where F =
the number of front channels and S = the number of surround channels.
LFE = 1 if the LFE channel is on.
For example, a given source may display 3/2.1, indicating that the
source was mixed with 3 front channels, 2 surround channels, and the
LFE channel. When the designation .1 indicates that the LFE channel
is on, as in our example, a level meter at the bottom of the display will
show LFE channel activity. (Note, that there may be instances where the
LFE channel is on, but no activity shows in the meter display.)
REF OFFSET indicates the Dialog Normalization value that is present
in AC-3 bitstreams. In AC-3, dialog is reproduced at -31dBFS (31dB
below full scale). If the program material was mixed so that dialog is at
-31dBFS, then REF OFFSET=0dB. If the dialog was mixed at a "hotter"
level, for example, -27dBFS, then REF OFFSET = -4dB and the SDP-3
would adjust the levels down 4dB to bring dialog back to -31dBFS.
AC-3 STATUS
DOWNMIX
SAMPLE RATE
DATA RATE
PGM CONTENT
REF OFFSET
NO
48kHz
384 kb/sec
3/2.1
-4dB
MATRIX ENCODED
NO
LFE
4
AC-3 Effects and Parameters
