Studio Technologies 68A 2005 - Manual (Page 31)

Model 68A/69A User Guide Issue 2, January 2005
Studio Technologies, Inc. Page 31
for Surround
stereo signals converted to mono. How
these functions affect the audio signals
will greatly depend on how the Model 69A
is confi gured. Being aware of the selected
confi guration will allow the functions to
serve a more useful role.
Downmix
The downmix function allows surround sig-
nals to be mixed or “folded down” into
a stereo (left and right) signal. Phase re-
lationships and inter-channel level issues
can be quickly observed. Please refer to
the Technical Notes section of this guide
for a detailed description of how the down-
mix function mixes surround to stereo.
Using the downmix function simply re-
quires the downmix button to be pressed.
The downmix button is always set to
“latch” the function on and off. The associ-
ated LED lights when downmix is enabled.
The stereo signal created by the downmix
function is routed to the left and right chan-
nels of the surround or the stereo output,
depending on which is active.
Depending on how the Model 69A Control
Console is confi gured, the downmix func-
tion may automatically enable whenever
the mono function is enabled. This is pro-
vided to ensure an operator hears a valid
mono signal when a surround source is
selected as an input.
Mono
The operating characteristics of the mono
function depend on the Model 69A Control
Console’s confi guration. Two mono modes
are available, as are four attenuation
levels. In the mono-to-left-and-right mode
the function combines (sums) the signals
on the left and right channels and routes
the result to both the left and right monitor
output channels. This method is the same
as found on many stereo-oriented audio
consoles. Useful for music mixing, it’s
not true monaural but rather binaural. As
expected, the mono signal will be routed
to the left and right channels of either the
surround or the stereo monitor output,
depending on which output is selected
by way of the surround/stereo button.
In the mono-to-center mode the mono
function combines (sums) the left and
right channels and routes the result to
the center channel of the surround out-
put. This function allows a more accurate
reproduction of a mono signal, but may not
be suitable for all operators. As expected,
in the mono-to-center mode the mono sig-
nal will always be routed to the surround
center channel, no matter whether the sur-
round or the stereo output is selected by
way of the surround/stereo select button.
To enable the mono function simply re-
quires the mono button to be pressed. The
mono function is always set to “latch” the
function on and off. The associated LED
will light whenever mono is enabled.
Bandpass Filter for Mono-to-Center
Mode
A special feature has been included to
assist an operator in determining compat-
ibility with “real world” playback environ-
ments. A bandpass fi lter can be inserted
into the path of the mono signal when it is
being routed to the center channel. This
allows the simulation of the response of a
loudspeaker associated with an inexpen-
sive monaural television or portable radio.
The fi lter passes signals in the range of
100 Hz to 5 kHz, while rejecting those
above and below.
To highlight for clarity, the bandpass fi lter
is only available for use when mono has