Bose 3-2-1GS Series II Service Manual page 64

2. Phase Test
2.1 Remove the array grille using array
disassembly procedure 1.
2.2 Observing polarity, apply a +6 Vdc level
to one driver on the array input connector.
2.3 Observe the Twiddler
the DC level is applied, the driver should
move outward. If it does, the Twiddler is
wired correctly. If not, it is wired incorrectly.
Repeat steps 2.2 and 2.3 for the other driver
in the array.
3. Air Leak Test
3.1 Apply a 180 Hz, 3 Vrms signal to one
of the Twiddler drivers in the satellite array
for 5 seconds minimum.
3.2 Listen for air leaks around all enclosure
seams, joints and the input connector. Air
leaks will be heard as a hissing or sputtering
noise. Repair any air leaks. All repairs must
be hidden.
3.3 Listen for any rubbing or ticking noise
from the Twiddler. Replace any driver that is
defective.
Note: There is a normal suspension noise.
To distinguish between a rub or tick and
suspension noise, displace the cone slightly
with your finger. If the rubbing can be made
to go away or get worse, then it is a rub or
tick. If the noise stays the same, it is
suspension noise.
3.4 Repeat steps 3.1 to 3.3 for the other
driver in the array.
TEST PROCEDURES
under test. When
TM
64
4. Frequency Sweep Test
4.1 Jumper both of the drivers in a single
array together. Both center pins of the array
connector are negative (-). The two outer
pins are the positive (+) pins.
4.2 Apply a 100 Hz, 3.0 Vrms signal to both
of the array drivers.
4.3 Slowly sweep the signal generator from
100 Hz to 2.0 kHz. Listen for any extraneous
noises such as buzzes, rattles, ticks, port
noise or distortion. Replace any array with
an extraneous noise that can be heard at a
distance greater than 1 foot (0.3m).