Mackie SWA2801z Owner's Manual - Page 4

REAR PANEL DESCRIPTION 1. POWER Switch Use this switch to turn the SWA2801z on and off. Make sure the signal source's level control is turned down before you turn it on. 2. AC Receptacle This is where you connect the AC linecord to provide AC power to the SWA2801z's built-in power amplifier. Plug the linecord into an AC socket properly configured for your particular model. 3. LIMIT Indicator The SWA2801z has a built-in limiter that prevents the amplifier outputs from overdriving the transducers. The LIMIT indicator lights when the limiter is activated. It's okay for the LIMIT indicator to blink occasionally, but if it blinks frequently or lights continuously, turn down the level control until the LIMIT indicator only blinks occasionally. 4. SIGNAL Present Indicator This LED illuminates whenever there is a signal present at the FULL RANGE INPUT connector on the rear panel. 5. THERMAL Indicator The SWA2801z has a thermal protection circuit that monitors the internal temperature of the amplifiers and heatsink. If the internal temperature should exceed a safe operating level, this indicator lights and the signal is muted to allow the amplifier to cool. When the temperature cools to a safe level once again, the thermal protection circuit deactivates and normal operation resumes. Note: Activation of the thermal protection circuit is an indication that you should take steps to avoid continued thermal problems. See "Thermal Considerations" on page 7. PARALLEL 6. POWER Indicator When the POWER switch is turned on and the linecord is connected to an active AC power supply, this indicator lights green to let you know that you're ready to rock and roll. The cool blue LED on the front of the cabinet works in the same way. 7. FULL RANGE INPUT These are female XLR-type connectors that accept a balanced line-level signal from a mixing console or other signal source. 8. THRU (FULL RANGE OUTPUT) These are male XLR-type connectors that produce exactly the same signal that is connected to the FULL RANGE INPUT jack. Use it to daisy-chain several SWA2801z's together off the same signal source. 9. HIGH PASS (MID/HIGH FREQ) OUTPUT These are male XLR-type connectors that produce the frequencies above 120 Hz. Connect these to a pair of full-range active speakers or to an amplifer/passive speaker combination. The SWA2801z reproduces the frequencies below 120 Hz. 10. SUBWOOFER LEVEL Control This adjusts the subwoofer level. The center detent position provides 15 dB of headroom with a nominal +4 dBu input signal. Use this as a starting point for setting the balance between the subwoofer and the main speakers. 11. PHASE This switch reverses the polarity of the subwoofer output. Depending on the placement of the SWA2801z subwoofer relative to the full-range speakers, you may get a better low-frequency response in the room if you reverse the polarity of the subwoofer's signal. Experiment with this switch to determine which position sounds best.