572
6
Calibration Settings Table
Set the controls and switches on the front and rear panel as shown below.
Front Panel Control
Setting
Rear Panel
Setting
B
YPASS
switch
out (NORM)
O
UTPUT
Connect to power amplifiers.
P
AGE
M
IC
gain
12:00 o’clock
P
AGE
M
IC
Connect balanced, low-impedance
page microphone here.
S
ENSE
G
AIN
switch
out (HIGH)
M
USIC
I
N
Connect line-level music source here.
S
AMPLE
I
NTERVAL
8:00 o’clock
P
AGE
I
N
Connect line-level paging source here.
P
AGE
O
VER
M
USIC
8:00 o’clock
R
ATIO
12:00 o’clock
L
EVEL
S
ET
M
IN
9:00 o’clock
L
EVEL
S
ET
M
AX
8:00 o’clock
O
PTION
switches
All down
Calibration Checklist
You initiate the calibration procedure by pressing the M
ODE
switch once (from O
PERATE
mode).
Complete the following checklist before beginning the calibration procedure.
•
Complete all input and output connections.
•
Apply power to the 572.
•
Verify that the unit passes signal in the B
YPASS
mode. Enter B
YPASS
mode by depressing the
B
YPASS
switch. Return the B
YPASS
switch to the OUT position. You should still have audio.
•
Set Option switch B to the UP position (sense view). Observe the LED bargraph. There should
be at one LED on, up to a maximum of 7 LEDs on. If no LEDs are on, depress the S
ENSE
G
AIN
switch. Leave the switch in whatever position results in a reading between the first and last
LEDs in the bargraph.
•
Set the front and rear panel controls as shown in Calibration Settings Table (previous page).
Caution
The 572 resistively mixes its line inputs in Bypass mode. This can cause attenuation
whose amount depends upon the actual source devices as well as the amplifier(s)
connected to the unit’s outputs.
The 572 delivers unity gain when the output is operated unbalanced, and the gain
is +6 dB when the output is operated balanced.
Calibration Procedure
1.
Apply program or paging signals to the 572’s input(s).
2.
Press the M
ODE
switch once to enter C
AL
ibration mode.
3.
Using the 572’s L
EVEL
S
ET
M
IN
control, adjust the control for the minimum desired
operating level when the LED bargraph indicator marked S
ET
M
IN
flashes.
4.
Using the 572’s L
EVEL
S
ET
M
AX
control, adjust the control for the maximum desired
operating level when the LED bargraph indicator marked S
ET
M
AX
flashes.
The 572 “listens” to the sound system for about 8 seconds at the minimum level (after it detects the last
adjustment of the M
IN
control), and then for about 8 seconds at the maximum level (after the last
adjustment of the M
AX
control). Then the microprocessor returns the unit to O
PERATE
mode under the
new calibration values.
When the calibration procedure is completed, the acoustic performance record of the room is placed in
nonvolatile memory along with the minimum and maximum level settings. The unit will operate under
these calibration settings until the calibration procedure is run again.
The calibration procedure may be run as many times as necessary. If for any reason the procedure is
interrupted before completion, the unit returns to operate mode under the previously stored values. If
the procedure is run to completion with no changes, the unit calculates the same values as it did under
the previous calibration procedure, and puts those new values into nonvolatile memory. Only when the
level set max or L
EVEL
S
ET
M
IN
setting is changed does the unit put new operating values into memory.
You can force sensing by turning the sample interval control to 1 and then quickly returning it to 5.
You can also force sensing by using option switch D and TB2-3.
