LD Systems SUB 88 A - Active Subwoofer 2 x 8" User Manual

1. Introduction

The LD Systems SUB88A active subwoofer features two 8" loudspeakers and delivers 600 W Peak power. The SUB88A is the active version of the SUB88, one of our most popular subwoofers. It is equipped with a 600 Watt (peak) mono amplification module that offers excellent sound and dynamic characteristics. This subwoofer is the ideal partner for our SAT62A active loudspeakers, our SAT42/242/62 passive loudspeakers in combination with an external amplifier (like DJ200), or for all types of satellites if you wish to enrich the sound with deep and powerful bass.

Figure 1: Front and side view of the LD Systems SUB 88 A Active Subwoofer.

2. Safety Instructions

Please read these safety instructions carefully before operating the device. Keep this manual for future reference.

• Power Source: Connect the device only to a power supply of the type described in this manual or marked on the device.
• Ventilation: Ensure proper ventilation. Do not block any ventilation openings.
• Water and Moisture: Do not expose the device to rain or moisture. Do not place objects filled with liquids, such as vases, on the device.
• Heat: Do not place the device near heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat.
• Cleaning: Clean only with a dry cloth.
• Servicing: Do not attempt to service this product yourself as opening or removing covers may expose you to dangerous voltage or other hazards. Refer all servicing to qualified service personnel.
• Cables: Protect the power cord from being walked on or pinched, particularly at plugs, convenience receptacles, and the point where they exit from the apparatus.

3. Package Contents

Verify that all items are present and in good condition upon unpacking.

• LD Systems SUB 88 A Active Subwoofer
• Instruction Manual

4. Product Overview

Familiarize yourself with the various components and controls of your SUB 88 A subwoofer.

Figure 2: Front view of the subwoofer, showing the bass reflex port.

Figure 3: Rear panel of the subwoofer, displaying input/output connections and controls.

Figure 4: Close-up view of the rear panel controls, including SUB LEVEL, SUB CROSSOVER, SUB PHASE, and input/output ports.

Rear Panel Controls and Connections:

• POWER Switch: Turns the subwoofer on or off.
• AC Input: Connects the power cable.
• FUSE Holder: Contains the main fuse for protection.
• INPUT (XLR/TRS Combo Jack): Main audio input for connecting to a mixer or audio interface.
• SUB LEVEL Knob: Adjusts the overall output volume of the subwoofer.
• SUB CROSSOVER Knob (80 Hz - 200 Hz): Sets the upper frequency limit for the subwoofer. Frequencies above this setting will be sent to connected satellite speakers (if applicable).
• SUB PHASE Switch (0°/180°): Adjusts the phase of the subwoofer output to match the phase of your main speakers, preventing phase cancellation.
• LIMIT LED: Illuminates when the internal limiter is active, indicating that the signal is too high.
• SIGNAL LED: Illuminates when an audio signal is present.
• POWER LED: Illuminates when the unit is powered on.

5. Setup

Follow these steps to properly set up your LD Systems SUB 88 A subwoofer.

1. Placement: Position the subwoofer on a stable, flat surface. For optimal bass response, consider placing it in a corner or near a wall. Avoid blocking the bass reflex port.
2. Power Connection: Ensure the POWER switch is in the OFF position. Connect the supplied power cable to the AC Input on the rear panel and then to a suitable power outlet.
3. Audio Connection:
   • Connect the audio output from your mixer, audio interface, or pre-amplifier to the INPUT (XLR/TRS Combo Jack) on the subwoofer's rear panel using a balanced XLR or TRS cable.
   • If connecting satellite speakers, ensure they are connected to the appropriate outputs on your mixer/interface, or if your setup allows, route them through the subwoofer's high-pass outputs (if available, though not explicitly listed for this model, typical for subwoofers).
4. Initial Settings:
   • Set the SUB LEVEL knob to its minimum (MIN) position.
   • Set the SUB CROSSOVER knob to an initial setting, typically around 100 Hz for general use. Adjust later for optimal sound.
   • Set the SUB PHASE switch to 0°. You may need to adjust this later during calibration.

6. Operating

Instructions for operating your LD Systems SUB 88 A subwoofer.

1. Power On: Once all connections are made, switch the POWER button to the ON position. The POWER LED should illuminate.
2. Volume Adjustment: Start playing audio through your system. Slowly increase the SUB LEVEL knob until the desired bass level is achieved. Ensure the LIMIT LED does not illuminate frequently, as this indicates signal clipping.
3. Crossover Adjustment: Adjust the SUB CROSSOVER knob to blend the subwoofer's output seamlessly with your main speakers. A lower setting (e.g., 80 Hz) is suitable for larger main speakers, while a higher setting (e.g., 120 Hz or more) may be needed for smaller satellite speakers. Experiment to find the best balance.
4. Phase Adjustment: While playing music with strong bass, toggle the SUB PHASE switch between 0° and 180°. Choose the setting that produces the most impactful and defined bass. This compensates for acoustic phase differences between the subwoofer and main speakers due to their placement.
5. Monitoring: Pay attention to the SIGNAL and LIMIT LEDs. The SIGNAL LED confirms audio input. If the LIMIT LED flashes frequently or stays lit, reduce the input signal level from your source or decrease the SUB LEVEL to prevent distortion and potential damage.

7. Maintenance

Proper care and maintenance will ensure the longevity of your subwoofer.

• Cleaning: Disconnect the power before cleaning. Use a soft, dry cloth to wipe the exterior surfaces. Do not use liquid cleaners, aerosols, or abrasive chemicals.
• Ventilation: Ensure that the ventilation openings are free from dust and debris. Periodically clean them with a soft brush or vacuum cleaner.
• Storage: If storing the subwoofer for an extended period, keep it in a cool, dry place, away from direct sunlight and extreme temperatures.
• Fuse Replacement: If the unit does not power on, check the fuse in the FUSE holder. Replace it only with a fuse of the same type and rating as specified on the unit. Refer to qualified service personnel if unsure.

8. Troubleshooting

Refer to this section for common issues and their solutions.

9. Specifications

10. Warranty and Support

This product comes with a limited warranty. For detailed warranty information and technical support, please refer to the official LD Systems website or contact your local distributor. Keep your proof of purchase for warranty claims.

For further assistance, visit the LD Systems Store on Amazon.