Studio Technologies 761 - Manual (Page 18)

Issue 1, March 2008 Model 761/771 User Guide
Page 18 Studio Technologies, Inc.
for Surround
7. To complete the process the confi gura-
tion mode must be exited. This is per-
formed by again pressing and holding
the confi gure button for two seconds.
The new reference level is now stored
in the Model 761’s nonvolatile memory.
Only by repeating the entire procedure
can the value be changed.
Once the confi guration mode has been
exited, the monitor outputs will again be-
come active. Confi rm that the correct level
has been stored by pressing the reference
button. The SPL meter should display the
desired level. If not, repeat the calibration
procedure to achieve the goal.
You might wonder why you have to press
and hold the reference button for fi ve
seconds before the selected value is rec-
ognized. This is provided specifi cally so
that unauthorized users won’t accidentally
change the reference level while they ex-
periment with the confi guration mode. Only
if you know the “secret” will you be able to
store a new value.
Overall Display Mode
The Model 771’s 4-digit numeric display
can be confi gured to display the output
level in either an attenuation mode or an
SPL mode. In the attenuation mode the
output level is shown as a reduction in
value relative to the maximum output level.
When the rotary level control is at its fully
clockwise position the maximum output
level is obtained and the display will show
0.0. As the rotary control moves in the
counterclockwise direction the display will
show negative values, reaching approxi-
mately –69.5 dB before the full mute func-
tion automatically mutes the outputs.
In the SPL mode the display can be
confi gured to allow the output level to
be presented to a user in terms of the
actual sound pressure level (SPL). Used
in conjunction with the SPL reference level
confi guration and the stored confi guration
level, SPL mode allows a user to see a vi-
sual representation of the SPL level that is
present in the listening environment. While
correct implementation of the SPL display
mode takes a little more care, it can offer
an enhanced experience for StudioComm
users.
SPL Reference Level
The SPL reference level confi guration
allows a specifi c SPL number to be associ-
ated with the stored reference level value.
In this way whenever the monitor output is
at the stored reference level, either through
activating the reference level function or
manually adjusting the rotary level con-
trol, the Model 771’s display will show the
confi gured SPL level. Whenever the moni-
tor output is not at the reference value the
display will show the current value, in dB,
relative to the reference level. The SPL
reference level can be confi gured over a
range of 70.0 to 100.0 dB in one-dB steps.
In many applications a value of 85 would
be appropriate, refl ecting the widely used
audio-for-picture 85 dB monitoring refer-
ence level. (Typically this 85 dB is really
85 dBC, indicating that a C-weighting fi lter
has been applied to the measurement.)
Other common reference SPL values,
such as 82 and 87, are well within the
allowable range.
Dialnorm Reference Level
The dialnorm reference level parameter is
provided so that the StudioComm system
can be confi gured to match a facilities’ or