Bose L1 Compact Service Manual

The Bose L1 Compact is a portable line array loudspeaker system designed for musicians and presenters. It integrates a power amplifier, tone match audio engine, and multiple loudspeaker drivers into a single, column-shaped unit. This service manual provides detailed information for qualified technicians regarding safety procedures, system overview, disassembly, troubleshooting, parts replacement, and reassembly. Below are key sections for safety, system overview, service procedures, and technical specifications.

Safety Information & Precautions

This section contains critical safety information for service personnel. Read and understand all warnings before proceeding.

System Overview & Components

Key components: Column Array (contains multiple drivers), Base Unit (houses amplifier, power supply, and controls), and optional T1 ToneMatch Audio Engine.

1. Column Array: Contains 8 custom-designed drivers arranged in a line array configuration.
2. Base Unit: Houses the Class-D power amplifier module, switching power supply, input/output connectors, and control knobs.
3. Controls: Master Volume, Tone (Bass/Treble), and Channel 1/2 Volume controls located on the base.
4. Connectors: Two combo XLR/TRS inputs, one RCA aux input, one XLR link output, AC power inlet.

WARNING! Do not operate the system with the column removed from the base, as this may damage the amplifier.

Disassembly Procedures

Follow these steps in order to access internal components. Document cable orientations and connector positions.

1. Power Down & Prepare: Unplug AC cord. Remove the column from the base by rotating the locking collar and lifting straight up.
2. Base Cover Removal: Remove the rubber feet to access screws. Remove all perimeter screws securing the bottom cover. Carefully lift the cover.
3. Amplifier/Power Supply Access: After removing the cover, the main amplifier board and power supply are visible. Note cable connections before disconnecting.
4. Driver Access (Column): To access drivers, carefully remove the front grille cloth (if serviceable per model). Driver mounting screws are accessible from the front.

CAUTION! The grille material is delicate. Use proper tools to avoid tearing.

Technical Specifications

• Amplifier Power: Integrated Class-D amplifier.
• Frequency Response: 56 Hz – 16 kHz (±3 dB).
• Coverage Pattern: 180° horizontal, 40° vertical.
• Inputs: 2 x Combo XLR/TRS (mic/line), 1 x RCA (line-level).
• Output: 1 x XLR (link to another system).
• Power Requirements: 100-240V AC, 50/60Hz, auto-switching.
• Dimensions (H x W x D): Column and base assembled dimensions.
• Weight: Total system weight.

Troubleshooting Flowcharts

Use these flowcharts to diagnose common system failures. Begin with the most obvious checks.

No Power: Check AC outlet > Verify power cord > Check internal fuse on power supply board > Test AC inlet > Test power supply output voltages.

No Audio Output: Verify input source > Check cable and input selection > Test with known good source into Channel 2 > Check internal audio path connections > Test amplifier module output.

Distorted Audio: Check input levels (avoid clipping) > Test with different source > Inspect drivers for physical damage > Test amplifier module.

One Channel Not Working: Swap inputs to rule out source > Check internal connector for that channel's preamp stage > Inspect PCB for cold solder joints.

PCB Layouts & Schematics

Reference diagrams for main amplifier board and power supply board. Diagrams show component placement, test points (TP), and connector pinouts.

1. Main Amplifier Board (AWM-XXXX): Shows audio input stages, DSP section (if applicable), Class-D output stage, and control knob connections.
2. Switching Power Supply (PSU-XXXX): Shows primary and secondary sides, fuse location, voltage outputs (+/- rails, logic +5V, etc.).
3. Test Point Voltages: List of expected DC voltages at key test points under no-load and operational conditions.

WARNING! Live measurements should only be performed by qualified personnel using appropriate isolation equipment.

Parts List & Exploded Views

Lists all serviceable parts with Bose part numbers. Exploded views show assembly order and relationship of parts.

NOTE: Order parts directly through authorized Bose service centers.

Reassembly & Testing

Reverse the disassembly procedure. Pay special attention to the following:

1. Ensure all cables are routed correctly and not pinched.
2. Secure all connectors firmly.
3. Install all screws in their original locations. Apply correct torque.
4. Before applying power, perform a visual inspection and continuity check (with power off) for obvious shorts.
5. Power-Up Test: Apply AC power. Check for normal indicator lights. Test all inputs with a low-level signal, gradually increasing volume to check for clean audio on all drivers.

CAUTION! Do not fully assemble the enclosure until basic functional testing is complete.

Firmware Update Procedure

The L1 Compact may contain updatable firmware for the audio engine. Updates are performed via a USB connection (if supported) or by replacing a memory chip.

1. Obtain the correct firmware file and update tool from Bose.
2. Connect the system to a computer via the specified service port.
3. Run the update utility and follow on-screen instructions.
4. Do not interrupt power during the update process.
5. The system will reboot automatically upon completion.

WARNING! An interrupted update may render the system inoperable.

Regulatory & Compliance

This product complies with relevant directives and standards: FCC Part 15 (Class B), CE (EMC Directive, Low Voltage Directive), RoHS. Contains no user-serviceable parts inside. Refer to the product label for specific certification marks and identification numbers.

Contact Information

Disclaimer: This manual is for use by qualified service technicians. Bose reserves the right to make changes without notice.