Studio Technologies 76DBA V.3.00 - Manual (Page 25)

Model 76DBA/77B User Guide Issue 1, November 2010
Studio Technologies, Inc. Page 25
for Surround
Input Delay
A time delay can be added to the input
signals, allowing compensation for delays
that may be present on associated video
signals. The selected time delay applies
to all input signals and cannot be applied
selectively. The configured delay time is
referenced to a sample rate of 48 kHz.
In the case of input signals with a sample
rate of 48 kHz the delay range is 0 to
340 milliseconds in 1-millisecond steps.
For other sample rates the time must be
linearly scaled. For example, for a sample
rate of 96 kHz the actual time range is 0 to
170 milliseconds. In this case selecting a
delay of 120 on the Model 77B will result in
an actual time delay of 60 milliseconds. For
192 kHz sampling the time range is 0 to 85
milliseconds. Selecting a delay of 240 will
result in a time delay of 60 milliseconds.
LFE Downmix Mode
By default, when the 5.1 to stereo down-
mix function is active the LFE channel
associated with a surround input is muted.
This removes LFE content from the down-
mixed signal. In most applications this is
appropriate. However, for special situations
a configuration mode allows the LFE chan-
nel to be part of the downmix signal flow.
When the LFE downmix mode is enabled,
if surround input A or B is the currently
selected input and the 5.1 to stereo down-
mix function is active, the LFE signal level
is reduced in level by 6 dB and added to
both the left and right output channels. As
expected, even when the LFE downmix
mode is active the digital and analog LFE
output channels will still mute when 5.1 to
stereo downmix is active.
Pre-Fader Surround Digital
Monitor Output Mode
The pre-fader surround digital monitor
output can be configured as to its place
in the Model 76DBA’s signal flow. The
choices are pre- or post-downmix. In the
pre-downmix mode the digital monitor out-
put channels will not be impacted by the
state of the downmix functions. This setting
would be appropriate if the pre-fader digi-
tal surround monitor outputs were being
routed to a storage system, routed
to another facility, etc. In this case the
action of an operator enabling or disabling
the downmix functions won’t impact the
pre-fader surround digital monitor output
signals. If the post-downmix mode is
selected the pre-fader surround digital
monitor outputs will reflect the actions of
the downmix functions. This choice would
be correct if, for example, level meters
were connected to the pre-fader surround
digital monitor outputs. In this scenario an
operator would want to visually observe
the actions that the downmix functions
impart on the signals.
Channel Pop Solo Mode
Offset Levels
Two parameters can be configured that
determine how the channel pop solo func-
tion impacts audio levels. The up offset
level sets the amount of increase (gain)
that a channel will experience when it is
soloed in the channel pop solo mode. The
down offset level sets the amount of de-
crease (attenuation) that the non-soloed
channels will experience when a channel
is active in the channel pop solo mode.