Specifications

When installing and using the APL-10/12, some simple precautions should be

followed. These include:

(1) Maintain Proper Air Flow

The APL-10/12 speakers are radiant- and convection-cooled devices. The alu-

minum heat-exchanger mounted on the rear surfaces provides primary cool-

ing of the system. Care must be taken to locate the units away from heat reg-

isters, heat-generating appliances, lighting equipment, and any other appara-

tus that could raise the temperature of the nearby air.

The APL-10/12 speakers require unimpeded air circulation in order to func-

tion properly (this is especially important when multiple units are used in

stacked and/or tight-pack configurations). The APL’s rear surface should be

located at least 18" away from walls and/or ceilings. Lamps, especially of the

high intensity or theatrical type, should never be allowed to shine directly on

the heat exchanger.

(2) Ambient Temperature

The APL-10/12 speakers are designed to be used in ambient temperatures

ranging from 32°F - 113°F (0°C - 45°C). Higher or lower temperatures

could cause system shutdown or result in early component failure. When

used outdoors on a hot day, take precautions to avoid direct sunlight on the

rear heat exchanger. Direct, intense sunlight can raise the temperature of the

heat exchanger to a point where the amplifiers may be required to shutdown

to avoid permanent damage.

(3) More About Heating and Cooling

The APL-10/12 speakers have a relatively complex thermal dynamic system.

They contain several heat sources (amplifiers, power supplies, and drivers)

that generate significant heat but only when program material is being repro-

duced. They are cooled primarily through heat radiation from the rear panel

as well as by convection; and secondarily, by a small degree of air movement

generated by the cone drivers.

Because the heat output of the system is directly proportional to the dura-

tion and nature of the program material, the system may not reach thermal

stability for several hours after it is activated. For this reason, it is important

to test the system under actual conditions of use if questionable conditions

are present. Questionable conditions include:

(a) ambient temperature at or above the maximum rating

(b) intense sunlight or artificial light shining on the heat exchanger

(d) combinations of the above

Installation