Bose 502 B Manual

The Bose 502 B is a professional loudspeaker system designed for commercial sound reinforcement applications. It features a unique Articulated Array® design with multiple high-frequency drivers for wide, even coverage, a 12-inch low-frequency driver, weather-resistant construction, and versatile mounting options. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

Features at a Glance

Key components: Articulated Array® high-frequency section, 12-inch low-frequency driver, weather-resistant enclosure, integrated mounting points, and professional-grade connectors.

Feature	Description
Articulated Array®	Multiple high-frequency drivers for controlled horizontal dispersion
12-inch LF Driver	High-power handling for extended low-frequency response
Weather-Resistant	Designed for indoor/outdoor use with protective grille and materials
Input Connectors	Dual NL4 Speakon connectors for parallel wiring
Mounting Points	Integrated M10 threaded inserts for versatile mounting
Crossover	Internal passive crossover network (1.6 kHz)
Power Handling	Continuous: 300W, Program: 600W, Peak: 1200W
Impedance	8 ohms nominal
Frequency Response	55 Hz - 16 kHz (±3 dB)
Coverage Pattern	100° horizontal x 40° vertical

Installation

Unpack and inspect contents. Ensure proper mounting hardware and tools are available.

1. Choose mounting location: Consider coverage area, structural support, and safety.
2. Prepare mounting hardware: Use appropriate brackets, clamps, or stands rated for speaker weight.
3. Mount speaker: Secure using M10 threaded inserts; ensure all connections are tight.
4. Connect cables: Use professional-grade speaker cable with NL4 Speakon connectors.
5. Verify amplifier compatibility: Match impedance and power ratings.

WARNING! Speaker is heavy; use proper lifting techniques and secure mounting to prevent injury or damage.

First-Time Setup

After installation, configure system for optimal performance.

1. Power off amplifier before making connections.
2. Connect speaker to amplifier output using NL4 Speakon cable.
3. Set amplifier gain controls to minimum before powering on.
4. Power on amplifier and test with low-level audio signal.
5. Adjust amplifier gain and system EQ as needed for application.
6. Verify coverage pattern and adjust speaker aim if necessary.

CAUTION! Always power off amplifier when connecting/disconnecting speakers to prevent damage.

Specifications

• Type: Two-way loudspeaker system
• LF Driver: 12-inch (305 mm) high-power woofer
• HF Drivers: Multiple 2-inch (50 mm) compression drivers
• Crossover Frequency: 1.6 kHz
• Power Handling: 300W continuous, 600W program, 1200W peak
• Impedance: 8 ohms nominal
• Sensitivity: 96 dB SPL (1W/1m)
• Maximum SPL: 124 dB peak
• Frequency Response: 55 Hz - 16 kHz (±3 dB)
• Dispersion: 100° H x 40° V
• Enclosure: Weather-resistant polypropylene
• Dimensions: 24.5" H x 18.5" W x 14.5" D (622 x 470 x 368 mm)
• Weight: 48 lbs (21.8 kg)

Controls and Connections

No external controls on speaker. All connections via rear panel connectors.

Rear Panel: Dual NL4 Speakon connectors (parallel wired), M10 threaded mounting inserts.

Connector Wiring: Pin 1+: LF+, Pin 1-: LF-, Pin 2+: HF+, Pin 2-: HF- (standard wiring).

Amplifier Requirements: Professional amplifier with appropriate power rating (300-600W at 8 ohms recommended).

Connecting to Amplifiers

Use professional amplifier with proper power rating and NL4 Speakon outputs.

1. Ensure amplifier is powered off.
2. Connect NL4 cable from amplifier output to speaker input.
3. For multiple speakers, use parallel wiring with appropriate impedance calculations.
4. Secure all connections and strain relief.
5. Power on amplifier and test system at low volume.

Tip: Use heavy-gauge speaker cable (12-14 AWG) for runs over 50 feet to minimize power loss.

Operation and Coverage

The Articulated Array® design provides consistent coverage across listening area.

1. Position speakers to cover intended listening area with minimal obstructions.
2. Aim speakers slightly downward for optimal coverage in seated applications.
3. Use multiple speakers for larger areas, spacing based on coverage pattern.
4. Adjust system EQ to compensate for room acoustics if needed.
5. Monitor speaker performance and temperature during extended use.

WARNING! Do not exceed recommended power ratings to prevent driver damage.

Mounting and Positioning

Versatile mounting options for various applications.

1. Wall mounting: Use appropriate brackets secured to structural supports.
2. Pole mounting: Use compatible pole mounts with safety locking mechanisms.
3. Flying: Use certified flying hardware and professional rigging.
4. Ground placement: Use sturdy speaker stands rated for speaker weight.
5. Always secure with safety cables for elevated installations.

CAUTION! Have all mounting installations performed by qualified personnel.

Care & Maintenance

Regular inspection and cleaning ensure long-term performance.

1. Exterior cleaning: Use soft cloth with mild soap and water; avoid harsh chemicals.
2. Grille cleaning: Use soft brush to remove dust; do not remove grille unless necessary.
3. Connection inspection: Periodically check connectors for corrosion or looseness.
4. Mounting hardware: Inspect regularly for security and signs of wear.
5. Storage: Store in dry, temperature-controlled environment when not in use.

CAUTION! Do not use high-pressure water or solvents for cleaning.

Regulatory Information

Complies with applicable safety and EMC standards. This product is designed for professional use. Copyright and trademarks owned by Bose Corporation. For technical support and service, contact authorized Bose professional audio dealers or visit www.bose.com/professional.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No sound	Amplifier off/bad connections	Check amplifier power; verify cable connections; test with known working cable.
Distorted sound	Overdriven amplifier/damaged driver	Reduce amplifier gain; check for clipping; inspect driver visually if possible.
Intermittent sound	Loose connections/cable damage	Secure all connections; inspect cables for damage; replace if necessary.
Reduced output	Impedance mismatch/cable loss	Verify amplifier impedance settings; check cable gauge and length.
Uneven coverage	Poor positioning/obstructions	Reposition speaker; clear obstructions; adjust aim angle.

Service: Contact authorized Bose professional audio service center for internal repairs.

Support: www.bose.com/professional or contact local Bose professional dealer.