Specifications

To verify if a driver has failed, remove the front grille and listen to the system

at a moderate level. By lightly touching each driver while playing program

material, you can readily tell if it is actively radiating or passively responding

to the other driver’s pressure.

Before attempting to replace any parts in the APL-10/12, be certain to dis-

connect the power cable from the unit. Lethal voltages are present inside the

enclosure when the unit is connected to an AC mains supply!

The drivers in the APL-10/12 can be changed in just a few minutes. To gain

access, first remove the front protective grille with a Phillips screwdriver.

After the grille is removed, the driver itself can be removed by simply loos-

ening the eight (8) Allen-drive fasteners that retain it, and lifting it out of the

enclosure. If possible, perform this task with the enclosure resting on its rear

surface. This will ease the process and minimize the force that would other-

wise be placed on the driver as the fasteners are loosed, if the enclosure

were upright. To remove the driver after the eight Allen-drive fasteners have

been taken out, reach through the nearest bass port with your hand and push

the driver upwards. The gasket sometimes sticks a bit, so do not hesitate to

use a little force to unseat the driver from the gasket.

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 rapidly. It could also damage the other

driver in the enclosure.

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.