22
TEST PROCEDURES
Model MB24 and MB12 Series
III
Bass
Loudspeakers
Note: For the MB24, ensure that the speaker
under test is in PARALLEL mode for the
following tests. To check the mode the
speaker is set up to operate in, you will need
to remove the eight screws that secure the
input panel assembly in place and verify that
the jumpered connector plugged into the
crossover PCB is in the PARALLEL jack.
Refer to the disassembly procedures in this
service manual for instructions on how to
remove the input panel. This does not apply
to the MB12, as it has only one woofer.
1. Rub and Tick Test
1.1 Apply a 10 Vrms, 10 Hz signal to the
input terminals of the speaker.
1.2 No extraneous noise such as rubbing,
scraping or ticking should be heard.
2. Phase Test
2.1 Disconnect the connectors at the driver
terminals. Momentarily apply 10 Vdc + 1 Vdc
to the terminals, observing polarity when
connecting the DC power supply. Both of the
drivers should move outward when the DC
level is applied.
3. Frequency Power Sweep Test
3.1 Apply a 10 Vrms, 10 Hz signal to the
speaker input terminals.
3.2 Sweep the input frequency from 10 Hz
to 250 Hz.
3.3 Listen for any buzzes, rattles or other
extraneous noises from the loudspeaker.
Loudspeaker Wiring Diagrams
+
2-
2+
1+
1-
-
V2
HI
+
T1.4hp
+
-
-
+
V2
+
-
-
Biamped
Passive
1+
1-
2+
4-
4+
3-
3+ 2-
1+
1-
2+
4-
4+
3-
3+ 2-
3+
3-
4+
4-
Mid 1+
Mid 1-
Mid 2+
Mid 2-
To In+
To In-
Biamped(Dual Mid Range)
+
V2
+
-
-
+
V2
+
-
-
IN
HI+
HI-
+
OUT
-
EAG011-02
L1
0.72mH/
1.3mm
C1
3UF/250V
C2
6UF/250V
EAG011-03 V1.1
CON1
CON2
CON3
5556 2Î11P
4.5'
4.5'
4.5'
4.5'
4.5'
4.5'
4.5'
4.5'
Connector
MID-FREQUENCY DRIVERS
HIGH-FREQUENCY
DRIVER
Model 3202
®
Series
III
Wiring Diagram
