Studio Technologies 68A 2001 - Manual (Page 18)

Issue 1, March 2001 Model 68A/69A User Guide
Page 18 Studio Technologies, Inc.
for Surround
may require the level control to be set to
the 11- or 12-o’clock position. The modi-
fied log mode more closely matches the
monitor level control performance found
in many audio consoles. As such it is
selected as the default mode.
It’s important to note that changing the
level control response configuration will
impact the reference level. Changing from
modified log to true log, or vice-versa, will
change the reference level. Technically,
the mathematical value stored as the
reference level does not change, but the
loudness that is heard by the operator will
change. Be warned! Changing the level
control response may require the refer-
ence level to be re-calibrated.
Level Control Auto Mute All
The level control auto mute all function
automatically mutes the monitor output
channels whenever the rotary level control
is in its fully counterclockwise position. In
some applications it may be desirable to
disable this function. When disabled, the
rotary level control adjusts the monitor
output level over the approximately 72dB
range; no automatic muting takes place.
Reference Level
For audio-with-picture applications it’s
critical that mixing be done in reference
to a known monitor loudspeaker level. This
is often referred to as mixing to “85dB” on
the monitors. The Model 69A Control
Console allows a precise monitor output
level to be stored, and then enabled by
pressing the button labeled REF. Setting
the reference level is very simple:
1. Set up a precision sound pressure
level (SPL) measuring device at the
desired listening location.
2. Place the StudioComm system in the
normal operating mode, not the configu-
ration mode. Be certain that the refer-
ence and dim functions are not active.
3. Use the Model 69A Control Console
to select the input source that contains
the desired reference signal source,
e.g., pink noise.
4. Select the desired output, surround
or stereo.
5. Observing the SPL meter, adjust the
Model 69A’s rotary level control until the
desired reference output level has been
reached.
6. Being careful not to touch the position
of the rotary level control, enter the
configuration mode by pressing and
holding the configuration button located
on the Model 69A’s back panel.
7. Once the configuration mode has been
entered, the monitor outputs will mute.
Press and hold the reference button until
its associated LED lights. This will take
approximately 5 seconds. The LED will
light to indicate that a “snapshot” of the
new reference level has been taken.
8. To store the new reference level in
memory, exit the configuration mode by
again pressing and holding the configure
button.
This level is now permanently stored as the
reference level. Only by repeating the pro-
cedure can the value be changed.
Once the configuration mode has been
exited, the monitor output channels will
again become active. Confirm that the
correct level has been stored by pressing
the reference button. The SPL meter should
again display the desired level. If not, repeat
the calibration procedure.