Bose MA12 Manual

The Bose MA12 is a modular line array loudspeaker system designed for commercial sound applications, offering wide, even coverage with minimal feedback. It features a modular design allowing multiple units to be arrayed, integrated power amplifier modules, weather-resistant construction, and flexible mounting options. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

Features at a Glance

Key components: Modular line array enclosure, Integrated power amplifier module, Input/Output connectors, Mounting hardware, Control access panel.

Feature	Description
Modular Design	Multiple MA12 units can be arrayed vertically or horizontally
Integrated Amplifier	Built-in power amplifier with thermal and overload protection
Weather Resistance	Designed for indoor/outdoor use with protective grille
Wide Dispersion	120° horizontal x 5° vertical coverage pattern
Input Connectors	Euroblock connectors for audio input and link output
Mounting Options	Multiple brackets for wall, ceiling, or array mounting
Gain Control	Adjustable input sensitivity via recessed potentiometer
Status Indicators	LED indicators for power and signal presence
Thermal Protection	Automatic shutdown with thermal overload
Link Output	Parallel output for connecting additional speakers

Installation

Unpack and inspect contents. Determine mounting location based on coverage requirements.

1. Mounting: Use appropriate bracket for wall, ceiling, or array configuration.
2. Electrical connection: Connect to appropriate AC power source (100-240V, 50/60Hz).
3. Audio connection: Use shielded cable to Euroblock input connectors.
4. Array configuration: Connect multiple units using link outputs and array hardware.

WARNING! Ensure mounting surface can support weight. Use certified installer for array configurations.

First-Time Setup

Power on system; verify operation indicators.

1. Power connection: Connect to appropriate voltage AC source.
2. Audio input: Connect balanced line-level signal to input connectors.
3. Gain adjustment: Set input sensitivity using recessed potentiometer.
4. System verification: Check all status LEDs and audio output.

CAUTION! Ensure proper ventilation around amplifier module. Do not block cooling vents.

Specifications

• Type: Modular line array loudspeaker with integrated amplifier.
• Frequency Response: 90Hz - 16kHz (±3dB).
• Coverage Pattern: 120° horizontal x 5° vertical.
• Maximum SPL: 118dB peak at 1m.
• Amplifier Power: 150W continuous.
• Input: Balanced line-level via Euroblock connector.
• Input Sensitivity: Adjustable 0.775V - 2.4V RMS.
• Power Requirements: 100-240V AC, 50/60Hz, 1.5A max.
• Operating Temperature: -29°C to 60°C (-20°F to 140°F).
• Dimensions: 305mm H x 445mm W x 203mm D (12" x 17.5" x 8").
• Weight: 9.1kg (20 lbs).

Controls and Settings

Access controls via rear panel. Input Sensitivity: Adjust with recessed potentiometer (flat-blade screwdriver required).

Status Indicators: Green LED (power), Amber LED (signal present), Red LED (thermal/overload protection active).

Configuration: Single unit operation or array with multiple units. Array Alignment: Use alignment marks on enclosure sides for proper acoustic coupling. Gain Structure: Set input sensitivity to match source output level.

Connecting Devices

Audio Input: Euroblock connector (pins: 1=Ground, 2=Hot+, 3=Cold-). Link Output: Parallel output for daisy-chaining additional speakers.

1. Turn off all equipment before making connections.
2. Use shielded twisted-pair cable for audio connections.
3. Connect input to mixer/processor line output.
4. For arrays, use link output to next unit's input.

Tip: Maintain proper polarity throughout system. Use strain relief on all cables.

Operation Guidelines

Designed for continuous commercial operation.

1. Power sequence: Turn on sources first, then MA12. Reverse for shutdown.
2. Level setting: Adjust input sensitivity for optimal signal-to-noise ratio.
3. Array operation: Ensure proper alignment when using multiple units.
4. Monitoring: Regularly check status indicator LEDs.
5. Environmental: Suitable for indoor/outdoor use with proper mounting.

WARNING! Do not operate with red protection LED illuminated. Allow cool-down period if thermal protection activates.

System Configuration

Single Unit: Basic installation with one MA12. Vertical Array: Multiple units stacked for increased vertical coverage. Horizontal Array: Units placed side-by-side for wider horizontal coverage. Mixed Arrays: Combination for specific coverage patterns.

Care & Maintenance

Disconnect power before cleaning. Exterior: Wipe with damp cloth. Grille: Use soft brush to remove dust. Connectors: Keep free of corrosion and debris.

CAUTION! Do not use solvents or abrasive cleaners. Do not spray water directly onto unit.

Regulatory Information

FCC Part 15: Class A digital device; complies with limits for commercial use. CE marked for European compliance. UL/CSA listed. Copyright © Bose Corporation. All trademarks property of Bose Corporation. For technical support, visit www.bose.com or contact Bose Professional Products Division.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No sound output	Power/connections	Check AC power; verify input connections; check source.
Red LED illuminated	Overload/thermal	Reduce input level; allow cooling; check ventilation.
Distorted sound	Input clipping	Reduce source level; adjust input sensitivity.
Intermittent operation	Loose connections	Check all audio and power connections.
Hum or buzz	Ground loop	Ensure proper grounding; use balanced connections.

Reset: Power cycle unit if protection circuit activates.

Service: Contact Bose Professional Support or authorized service center.