Studio Technologies 68A 2005 - Manual (Page 18)

Issue 2, January 2005 Model 68A/69A User Guide
Page 18 Studio Technologies, Inc.
for Surround
the 11- or 12-o’clock position. The modi-
fi ed 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 confi guration will
impact the reference level. Changing from
modifi ed 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 recalibrated.
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 72 dB
range; no automatic muting takes place.
Reference Level
For audio-with-picture applications it’s criti-
cal that mixing be done in reference to a
known monitor loudspeaker level. This is
often referred to as mixing to “85 dB” on
the monitors. The Model 69A Control Con-
sole allows a precise monitor output level
to be stored, and then enabled by pressing
the button labeled REF. Setting the refer-
ence 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 confi g-
uration 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
confi guration mode by pressing and
holding the confi guration button locat-
ed on the Model 69A’s back panel.
7. Once the confi guration 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 “snap-
shot” of the new reference level has
been taken.
8. To store the new reference level in
memory, exit the confi guration mode
by again pressing and holding the con-
fi gure button.
This level is now permanently stored as
the reference level. Only by repeating the
procedure can the value be changed.
Once the confi guration mode has been
exited, the monitor output channels will
again become active. Confi rm that the cor-
rect level has been stored by pressing the
reference button. The SPL meter should