Studio Technologies 74 - Manual (Page 19)

Issue 2, January 2006 Model 74/75 User Guide
Page 20 Studio Technologies, Inc.
for Surround
channels. The amount of rotation required
to reach a specifi c level can be selected
from two modes. This can be described as
allowing the “curve” or “taper” of the level
control to be confi gured. The two available
modes are true logarithmic and modifi ed
logarithmic. In the true logarithmic mode
the level control provides a precise loga-
rithmic performance over its entire rotation,
e.g., the output level is half of its maximum
when the control is set at its midpoint, i.e.,
50% of its “travel.” In the true log mode,
normal listening may require the level con-
trol to be set to approximately the
“2-o’clock” position.
Other users may be more comfortable
with the response given by the modifi ed
logarithmic mode. This provides a much
greater output level during the fi rst 50% of
the level control’s travel. When confi gured
for the modifi ed log mode, normal listening
may require the level control to be set to
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 select-
ed as the default mode.
It’s important to note that changing the
level control response mode will impact the
reference level. Changing from modifi ed
log to true log, or vice-versa, will change
the reference level. Technically, the math-
ematical 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 reference 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 75 Control Con-
sole allows a precise monitor output level
setting to be stored, and then enabled by
pressing the button labeled Ref Level.
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 con-
fi guration mode. Be certain that the
reference and dim functions are not
active.
3. Use the Model 75 Control Console to
select the input source that contains
the desired reference signal source,
e.g., pink noise.
4. Select the desired monitor output,
speaker system A or B.
5. Observing the SPL meter, adjust the
Model 75’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 75’s back panel.