Jamo Sub 300 Manual

The Jamo Sub 300 is a high-performance powered subwoofer designed to deliver deep, powerful bass for home theater and audio systems. Featuring a 300W RMS amplifier, 12-inch long-throw driver, adjustable crossover frequency, phase control, auto on/off functionality, and multiple input options. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

Features at a Glance

Key components: 12-inch bass driver, 300W RMS amplifier, adjustable controls, multiple input options.

Feature	Description
Power Amplifier	300W RMS Class D amplifier
Driver	12-inch long-throw woofer
Crossover Frequency	40Hz - 150Hz adjustable
Phase Control	0° - 180° adjustable
Inputs	Line-level RCA, LFE input
Auto On/Off	Signal sensing power management
Power Switch	Main power control
Volume Control	Adjustable output level
Frequency Response	25Hz - 150Hz
Enclosure	Bass reflex design

Installation

Unpack and inspect contents. Choose optimal placement for best bass response.

1. Position subwoofer: Place in corner for maximum bass, or along wall for balanced response.
2. Connect audio sources: Use RCA cables to connect from receiver/amplifier subwoofer output.
3. Connect power: Plug into AC power outlet.
4. Set initial controls: Start with volume at 50%, crossover at 80Hz.

WARNING! Subwoofer is heavy; lift with proper technique. Ensure adequate ventilation around unit.

First-Time Setup

Power on subwoofer; follow setup procedure.

1. Connect to audio system: Use subwoofer cable from receiver LFE/subwoofer output.
2. Set crossover frequency: Match to main speakers' frequency response.
3. Adjust phase control: Set to 0° initially, adjust for best integration.
4. Calibrate volume: Use receiver's auto-calibration or manual adjustment.

CAUTION! Avoid placing near heat sources or in confined spaces.

Specifications

• Amplifier Power: 300W RMS
• Driver Size: 12 inches
• Frequency Response: 25Hz - 150Hz
• Crossover Range: 40Hz - 150Hz adjustable
• Inputs: Stereo RCA, LFE input
• Phase Control: 0° - 180° continuously variable
• Auto On/Off: Signal sensing technology
• Power Requirements: 110-120V AC, 60Hz
• Dimensions: Standard subwoofer cabinet size
• Weight: Approximately 45 lbs

Controls and Settings

Rear panel controls: Power switch, volume control, crossover frequency, phase control, input connections.

Volume Control: Adjusts subwoofer output level. Crossover: Sets upper frequency limit. Phase: Aligns subwoofer timing with main speakers. Auto On: Automatically powers on when signal detected.

Optimal Settings: Start with crossover at 80Hz, phase at 0°, volume at 50%. Fine-tune based on room acoustics and system configuration.

Connecting Devices

Multiple connection options: LFE input for home theater, stereo inputs for 2-channel systems.

1. Home Theater Connection: Use single RCA cable from receiver LFE output to subwoofer LFE input.
2. Stereo System Connection: Use stereo RCA cables from amplifier pre-out to subwoofer line inputs.
3. Speaker Level Connection: Use speaker wire connections if available.

Tip: Use high-quality shielded cables to minimize interference.

Operation Guidelines

For optimal performance and longevity.

1. Power Sequence: Turn on subwoofer before main system.
2. Volume Adjustment: Increase gradually to desired level.
3. Crossover Setting: Match to main speakers' capabilities.
4. Placement: Experiment with room placement for best bass response.
5. Break-in Period: Allow 20-30 hours of moderate use for optimal performance.

WARNING! Do not operate at maximum volume for extended periods.

Advanced Features

Phase Control: Adjusts timing alignment with main speakers. Auto On/Off: Conserves power when no signal detected. Crossover Bypass: Use LFE input for receiver-controlled crossover.

Care & Maintenance

Unplug before cleaning. Use soft, dry cloth for exterior. Keep ventilation ports clear of dust.

CAUTION! Do not use liquid cleaners. Avoid moisture exposure. Keep magnets away from electronic devices.

Regulatory Information

FCC Part 15: Class B digital device; complies with interference limits for residential use. Copyright © 2025 Jamo; all rights reserved. For support, visit www.jamo.com or contact customer service.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No sound	Power/connections	Check power connection; verify input cables; ensure auto-on function active.
Distorted sound	Overloading/clipping	Reduce volume level; check source material quality; verify proper gain structure.
Hum or noise	Ground loop/cables	Use grounded outlet; check cable quality; separate power and audio cables.
Auto on not working	Signal level/settings	Increase source volume; check auto-on switch position; verify signal present.
Weak bass	Placement/phase	Reposition subwoofer; adjust phase control; verify crossover settings.

Reset: Power cycle unit if experiencing issues.

Service: Contact authorized Jamo service center for technical support.