User Guide

Issue 4, December 2020 Model 780-01/790 User Guide
Page 18 Studio Technologies, Inc.
for Surround
there might be cases where this resource
isn’t desired and it can be disabled.
Bass Management
The Model 780-01 incorporates flexible
and sonically excellent bass management
capabilities. One configuration parameter
is used to enable or disable bass manage-
ment while three others are used to select
the characteristics of the associated au-
dio filters. While the settings are simple
to make, great care must be taken to first
review the entire monitor system. Only
after obtaining a full understanding of the
performance of the associated loudspeaker
system can a plan for the bass manage-
ment functions be selected.
The bass management function impacts
only the post-fader monitor output and by
default is disabled. The crossover point of
the seven main channels’ bass manage-
ment filters can be selected from among
four choices: 40, 50, 60, or 80 Hz. The
default value is 80 Hz. The slope of the
low-pass and high-pass filters associated
with the seven main channels’ bass man-
agement filters can be, as a group, select-
ed. The choices are 12 dB-per-octave or
24 dB-per-octave with the latter being the
default value. Setting the slopes to different
values (asymmetrical filtering on the seven
main channels) can be appropriate for
some loudspeaker systems.
Sync Source
The Model 780-01 requires that a designat-
ed external timing reference (sync) signal
be defined. Three of the choices—video,
DARS, and word clock—are associated
with a signal that is connected to the sync
input BNC connector. The fourth choice al-
lows the L/R input of the currently selected
surround or stereo input to also serve
as the system’s sync source. This fourth
choice is the default value.
Sync Input Termination
The sync input circuitry can be configured
to provide a 75 ohm termination impedance
to a connected source. When the sync input
is not terminated the input impedance is
very high, essentially applying no load to
the source. If the sync source is connected
only to the Model 780-01’s BNC input con-
nector then enabling termination is typically
appropriate. However, if the sync source is
being “shared” by multiple inputs then care
must be taken so that the signal is only
terminated by one device. By default sync
termination is enabled.
Audio-Synced-to-Video
Sample Rate
If a video sync signal is connected to the
sync input and video is selected as the
Model 780-01’s timing reference the sample
rate of the connected digital audio signals
must be explicitly specified. In most cases
the default value of 48 kHz will be appropri-
ate. But alternately 44.1, 88.2, or 96 kHz
can also be selected. This setting enables
the internal clock and timing circuitry to cor-
rectly interpret the video sync signal’s rela-
tionship to the connected audio sources.
Reference Level
For consistent monitoring of audio signals
it’s often beneficial for users to be able to
easily set the post-fader monitor output
level to a known value. This is sometimes
referred to as “mixing to 85 dB on the moni-
tors,” but the exact value will depend on
the application. The StudioComm system
allows a precise post-fader monitor output