There is also a male XLR connector labeled LOOP OUT. This is also wired according to the AES standard.

The LOOP OUT connector allows you to connect more than one SA1521 to your sys- tem. Simply plug the signal source (i.e., mixer output) into the first MAIN INPUT jack, and patch that speaker’s LOOP OUT jack to the next MAIN INPUT jack, and so on, daisy-chaining multiple speakers.

The LOOP OUT jack is wired straight from the MAIN INPUT connector — there is no electronic circuitry between — so the signal coming out of the LOOP OUT jack is exactly the same as the signal going in.

PLACEMENT

The SA1521 speaker is designed to sit on the floor or stage. It can be pole-mounted via the built-in socket on the bottom of the cabinet. Be sure the pole is capable of supporting the 100 lbs. weight of the SA1521.

WARNING: The cabi-

net has no rigging

points and is not suit-

able for flying. NEVER

attempt to suspend the SA1521 by its handles.

You can create a horizontal array by placing the cabinets side-by-side. However, you should have a good understanding of the relationship between the splay angle (the angle between the facing sides of the cabi- nets), the on-axis power, and frequency cancellation effects between cabinets.

When two cabinets are placed side-by-

side, the actual splay angle is 20º (determined by a 10º angle on each cabinet side). As the splay angle increases toward the angle of horizontal coverage (75º for the SA1521), the on-axis power decreases, but the frequency response becomes smoother as the comb-filtering effects (caused by the interaction in the area of double-coverage) decrease. As with any powered components, protect them from moisture. If you are setting them up outdoors, make sure

they are under cover if you expect rain.

AC POWER

Be sure the SA1521 is plugged into an

outlet that is able to supply the correct volt-

age specified for your model. If the voltage should drop below 97% of the specified line voltage, the built-in amplifiers will no longer be able to supply rated power. (They will continue to operate down to 80% of the rated line voltage, but won’t reach full power, resulting in lower headroom.)

Be sure the electrical service can supply enough amperage for all the components connected to it.

We recommend that a stiff (robust) supply of AC power be used because the amplifiers place high current demands on the AC line. The more power that is available on the line, the louder the speakers will play and the more peak output power will be available for cleaner, punchier bass. A suspected problem of “poor bass performance” is often caused by a weak AC supply to the amplifiers.

CAUTION: Never remove the ground pin on the power cord of the SA1521 or any other component. This is very dangerous.

THERMAL

CONSIDERATIONS

The SA1521 has two powerful built-in amplifiers capable of producing a combined 500 watts of power. As amplifiers produce heat, it is important to dissipate the heat as quickly as possible. This results in increased reliability and longevity for the amplifier. The amplifier module is mounted on a

large heatsink, which is cooled by convection where cool air is drawn through it’s fins, carrying the heat away. In order for this convection cooling to work efficiently, it is important to provide adequate airspace behind the loudspeaker. When you position the SA1521, we recommend leaving at least six inches of air space behind it.

In the unlikely event of the amplifier over- heating, a built-in thermal switch will activate, which mutes the signal and lights the THERMAL LED. When the amplifier has cooled down to a safe operating temperature, the thermal switch resets itself, and the SA1521 resumes normal operation.

If the thermal switch activates frequently, try turning down the level control a notch or two on the mixing console (or the back of the SA1521) to avoid overheating the amplifier.

If the temperature in the room is too high, it could cause the amplifier to overheat. In this case, you should try aiming a fan at the rear panel to move more air through the fins.

6