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force that would otherwise be placed on the driver as the fasteners are loos-
ened, if the enclosure were upright. To remove the driver after the eight
Allen-drive fasteners have been taken out, use a small, flat bladed screwdriv-
er to pry the driver upwards from the special access slot located at the bot-
tom of the enclosure’s front panel. The gasket sometimes sticks a bit, so do
not hesitate to use a little force to unseat the driver from the gasket.
Alternately, you can stand the enclosure upright so that the driver will fall
free on its own, being very careful not to damage it. The lower half of the
driver will break free first. It’s a good idea to keep your hand on it to keep it
from abruptly falling out and damaging the connection wires.
Once the driver has been removed from the enclosure, disconnect the
speaker wires from the terminals. To replace the driver, simply reverse the
disassembly process, making sure to connect the speaker wires properly. The
black wire goes to the black terminal on the driver, and the red or white wire
goes to the red terminal on the driver.
NOTE: If the driver is connected backwards (out of phase), it will not func-
tion properly and could be damaged if used adjacent to other APL-220, -500,
or -800 speakers in an array.
After the driver is connected, place it carefully over the opening and rotate
it to align its holes with the eight threaded inserts in the enclosure. Then,
install the fasteners, being careful to tighten them gradually in a cross-pattern
so as to equalize the force placed on the driver’s rim. Do not over-tighten
the fasteners or the driver’s rim may become warped! Two to three foot-
pounds of torque is sufficient.
After replacing the driver, power up the speaker system and play some pro-
gram material through it before replacing the grille. Verify that the new driv-
er is operating properly. If the system still exhibits problems, it may need
additional service work.
High-Frequency
The APL-800 high-frequency driver can be serviced by removing the front
protective grille and then removing the fasteners that retain the high-fre-
quency horn assembly. The horn and driver can then be lifted out of the
enclosure. Make sure to disconnect the wires to the HF driver. Once free of
the enclosure, the driver can be removed from the horn with a 7/
1
6" sock-
et or wrench. To replace the driver, simply reverse the disassembly process.
On the APL-220 and APL-500, the high-frequency driver is accessed by first
removing the protective grille and then the low-frequency cone driver. After
the cone driver has been removed, place the enclosure on its rear surface
with the front panel upwards. Loosen and remove all fasteners that attach the
