Studio Technologies 76D 2014 - Manual (Page 39)

Model 76D/77 User Guide Issue 11, May 2014
Studio Technologies, Inc. Page 39
for Surround
88.2, or 96 kHz.) Selecting a source with
a sample rate of 44.1, 48, 88.2, or 96 kHz
will resolve the issue and normal operation
will resume. Refer to the Technical Notes
section of this guide for additional details.
Downmix
Two downmix functions allow users to per-
form “real-world” audio format compatibility
checks. One function allows a surround
(5.1) signal to be “folded down” (mixed) to
stereo. The other allows a stereo signal to
be converted to mono. Using the downmix
functions simply requires pressing the de-
sired button. The buttons are set to always
“latch” the functions on and off. An LED is
located adjacent to each button and lights
whenever its respective function is active.
The downmix functions always impact the
post-fader surround and stereo monitor
outputs. And, depending on the selected
configuration, they may also impact the
pre-fader surround monitor output.
A specific downmix function can only be
enabled when it is applicable for the cur-
rently selected input source. This means
that the surround to stereo downmix func-
tion can only be enabled when surround
input A or B is selected.
The Model 77 associates the state of
the downmix functions with the currently
selected input. For example, if surround
input A is the selected input source and
the surround to stereo downmix function
is enabled, this condition will be “remem-
bered” when switching to one of the stereo
input sources. Upon returning to surround
input A, the surround to stereo downmix
function will again become active.
Surround to Stereo
When the surround to stereo downmix
function is enabled the LS, RS, and C
channels associated with a surround
source are combined (“folded down”) with
the L and R signals to create a 2-channel
stereo (left and right) signal. And, depend-
ing on the system’s configuration, the LFE
channel may also be combined with the L
and R signals. The resulting stereo sig-
nal, sometimes known as LtRt, is routed
to the L and R post-fader surround moni-
tor output channels. Also, whenever the
surround to stereo downmix function is
enabled the C, LS, RS, and SUB monitor
output channels are muted. By utilizing this
downmix function phase relationships and
inter-channel level issues can be quickly
observed.
Stereo to Mono
The stereo to mono downmix function
combines the L and R audio channels to
create a single-channel monaural signal.
This signal is sent out the C surround
monitor output channels while the L, R, LS,
RS, and SUB monitor output channels are
muted.
When a surround source has been select-
ed for monitoring, the surround to stereo
downmix function will automatically enable
whenever the stereo to mono downmix
function is enabled. This ensures that an
operator will hear a mono signal created
by folding down all channels associated
with the selected surround input.
Monitor Output General
Functions
Four buttons and one rotary control are
associated with the post-fader surround
and stereo monitor output functions. The