59
Test Procedures
Note: To distinguish between normal sus-
pension noise and rubs or ticks, displace the
cone slightly with your fingers. If the noise
stays the same, it is normal suspension
noise and the driver is good. Suspension
noise will not be heard with program mate-
rial.
3. Transducer Phase Test
3.1 Apply a DC voltage of 20V, positive
applied to the positive tab of the dual
banana jack on the bass module test cable
and negative applied to negative (gnd) tab.
3.2 Note that all driver cones move outward
when the DC voltage is applied.
3.3 Rewire any incorrectly connected trans-
ducers.
4. System Sweep Test
4.1 Set up the bass module as shown on the
previous page.
4.2 Apply a 10 Hz, 20 Vrms sine wave to the
Neutrik
®
Speakon
®
input connector.
4.3 While listening to the output of the
system, sweep the input frequency slowly
from 10 Hz to 400 Hz.
4.4 Listen carefully for any extraneous
noises such as buzzing and ticking.
B2 Bass Module Tests
1. Air Leak Test
1.1 Set up the bass module as shown on the
previous page.
1.2 Apply a 46 Hz, 14 Vrms sine wave to the
unit under test.
1.3 Listen carefully for air leaks from around
the end cap, the transducers and the grille.
Air leaks will be heard as a hissing or sput-
tering sound. All repairs must be hidden.
Test duration should be 5 seconds minimum.
2. Transducer Rub and Tick Test
2.1 Remove the transducer you wish to test
using the disassembly procedures in this
manual.
2.2 Connect a signal generator directly to
the terminals of the transducer assembly
under test.
2.3 Apply a 20 Hz, 14 Vrms signal to the
transducer assembly.
2.4 Listen carefully for any extraneous
noises such as rubbing, scraping or ticking.
Note: To distinguish between normal sus-
pension noise and rubs or ticks, displace the
cone slightly with your fingers. If the noise
stays the same, it is normal suspension
noise and the driver is good. Suspension
noise will not be heard with program mate-
rial.
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