1. Introduction
This manual provides instructions for the installation, operation, and maintenance of the Junsun 10-inch 1200W Slim Under Seat Subwoofer with Built-in Amplifier (Model JS-US-SUB105). Please read this manual thoroughly before installation and operation to ensure proper use and to prevent damage to the unit or vehicle. Retain this manual for future reference.
2. Safety Information
- Electrical Safety: Always disconnect the vehicle's negative battery terminal before beginning any electrical work. Ensure all wiring connections are secure and properly insulated to prevent short circuits.
- Professional Installation: If you are unsure about any part of the installation process, consult a qualified car audio professional.
- Placement: Mount the subwoofer securely to prevent it from shifting during vehicle movement. Ensure adequate ventilation around the unit to prevent overheating. Avoid placing the unit where it could be exposed to water or excessive moisture.
- Volume Levels: Prolonged exposure to high volume levels can cause hearing damage. Adjust volume to a safe and comfortable level.
- Fuse Protection: Always use the correct fuse rating as specified in the manual. Never replace a fuse with one of a higher amperage.
3. Package Contents
Verify that all items are present in the package before installation:
Figure 1: Junsun 10-inch under-seat subwoofer and complete wiring kit.
- Junsun 10-inch Slim Under Seat Subwoofer
- Audio Cable (RCA)
- Power Cables
- Remote Bass Volume Controller
- High to Low Level Converter
- Ground Wire
- Control Line
- Fuse
- Wiring Lugs
- User Guide (this manual)
4. Product Overview
4.1 Key Features
- Power Output: 1200W Peak Power and 300W RMS for low-frequency reproduction.
- Compact Design: Ultra-slim 3-inch profile (14″L x 10.24″W x 3″H) for installation in confined spaces such as under seats.
- Integrated Amplifier: Features adjustable Gain, Low-Pass Filter (40Hz-150Hz), and Bass Boost (0-12dB) controls for sound customization.
- Durable Construction: Cast aluminum housing designed for efficient heat dissipation, ensuring stable operation.
- Input Flexibility: Supports both High-Level and RCA Low-Level Inputs, compatible with factory and aftermarket stereo systems.
- Auto Turn-On: Automatic power on/off functionality.
- Protection Features: Built-in protection against overload, short-circuit, and thermal issues.
Figure 2: Subwoofer power output illustration.
4.2 Control Panel Layout
The control panel provides access to all necessary adjustments and connections. Refer to the diagram below for component identification.
Figure 3: Subwoofer control panel with labeled components.
- Power and Protection Indicator: Green indicates power on, Red indicates protection mode.
- Automatic Power On/Off Control Switch: Selects auto turn-on mode.
- Phase Transfer Switch: Adjusts audio phase (0° or 180°).
- Low Pass Filter Potentiometer: Adjusts the low-pass crossover frequency (50-150Hz).
- Bass Boost Potentiometer: Adjusts bass boost level (0-12dB).
- Gain Input Potentiometer: Adjusts the input sensitivity (volume).
- Remote Bass Volume Control Port: Connects to the included remote bass knob.
- High Level Input Port: For connecting speaker-level signals from a head unit.
- Low Level Input Port: For connecting RCA line-level signals from a head unit.
- Fuse Socket: Houses the main fuse for power protection.
- Power Input Terminals: Connections for +12V, Remote, and Ground wires.
5. Installation
5.1 Placement Considerations
The slim design of this subwoofer allows for flexible placement. Common locations include under a car seat or in the trunk. Ensure the chosen location provides adequate ventilation and allows for secure mounting.
Figure 4: Subwoofer installed under a car seat.
Figure 5: Mounting options and dimensions.
- Secure Mounting: Use the provided wiring lugs and screws to firmly attach the subwoofer to a solid surface in your vehicle. This prevents movement and potential damage.
- Ventilation: Do not obstruct the ventilation grilles of the subwoofer. Ensure there is sufficient airflow around the unit to prevent overheating, especially during extended use.
- Accessibility: Choose a location that allows access to the control panel for adjustments, or ensure the remote bass knob is installed in an accessible location.
5.2 Wiring Instructions
Before making any connections, disconnect the negative (-) terminal of your vehicle's battery to prevent electrical shorts. Use appropriate wire gauges for all connections.
5.2.1 Low-Level Input Wiring (RCA)
Low-level (RCA) input is recommended for optimal audio performance when your head unit has RCA outputs. Connect RCA cables from your head unit's subwoofer or full-range outputs to the LOW LEVEL INPUT ports on the subwoofer. Use a high-quality RCA cable of appropriate length (typically 6-12 feet for under-seat installations, 15-20 feet for trunk/hatchback installations).
Figure 6: Low-Level Input Wiring (left side of image) and High-Level Input Wiring (right side of image).
5.2.2 High-Level Input Wiring (Speaker Level)
If your head unit does not have RCA outputs, use the high-level inputs. Connect the speaker outputs from your head unit to the HIGH LEVEL INPUT port on the subwoofer. Ensure correct polarity (positive to positive, negative to negative) to avoid audio phase problems. The included High to Low Level Converter may be used for this connection.
NOTE: Do not connect both the high-level and low-level inputs from your receiver to your amplifier at the same time!
5.2.3 Power Connections
Proper power connections are crucial for the subwoofer's performance and safety.
Figure 7: Power Connection Diagrams.
- Ground (GND): Connect the ground terminal to the closest point on the vehicle's chassis. The ground wire should be less than 39 inches (100cm) in length and use 8 gauge (or heavier) wire. Ensure a clean, bare metal contact point.
- Remote (REM): Connect the remote terminal to the remote output of your head unit using 16 gauge (or heavier) wire. This wire signals the subwoofer to turn on and off with your head unit.
- +12V (BATT+): Connect an empty fuse holder within 18 inches (45cm) of the car battery. Run an 8 gauge (or heavier) cable from this fuse to the +12V terminal on the subwoofer. The fuse protects the power cable from short circuits.
NOTE: If using the AUTO TURN ON switch (B) in the ON position, the remote wire connection may not be necessary, as the subwoofer will detect an audio signal to power on. If AUTO TURN ON is OFF, a remote wire connection is required.
6. Operation
Once installed, adjust the subwoofer's settings to match your audio system and personal preferences.
- Gain Input (F): This control matches the subwoofer's input sensitivity to the output level of your head unit. Start with the gain at minimum, then slowly increase it until the bass blends well with your main speakers without distortion.
- Low Pass Filter (LPF) (D): This control sets the upper frequency limit for the subwoofer. Frequencies above this setting will not be reproduced by the subwoofer. Adjust it between 50Hz and 150Hz to blend smoothly with your main speakers. A common starting point is 80Hz.
- Bass Boost (E): This control provides an adjustable boost to bass frequencies (0-12dB). Use sparingly to avoid distortion.
- Phase Switch (C): This switch (0° or 180°) helps to align the subwoofer's output with the rest of your car's speakers. Listen to music with strong bass and switch between 0° and 180° to find the setting that produces the most impactful and coherent bass.
- Remote Bass Volume Control (G): Connect the included remote bass knob to this port for convenient adjustment of the subwoofer's output level from the driver's seat.
7. Maintenance
- Cleaning: Use a soft, dry cloth to clean the exterior of the subwoofer. Do not use harsh chemicals or abrasive cleaners.
- Connection Checks: Periodically inspect all wiring connections to ensure they remain secure and free from corrosion.
- Ventilation: Ensure that the subwoofer's ventilation areas remain unobstructed.
8. Troubleshooting
If you encounter issues with your Junsun subwoofer, refer to the following common problems and solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| No Power (Power LED off) | Blown fuse Poor power/ground connection No remote turn-on signal | Check and replace fuse Verify all power and ground connections Check remote wire connection or AUTO TURN ON switch setting |
| No Sound (Power LED on) | Low/High level input not connected Gain set too low Head unit volume too low Incorrect input selection (High/Low) | Check audio input connections Increase Gain setting Increase head unit volume Ensure correct input method is used |
| Distorted Sound | Gain set too high Bass Boost set too high Incorrect LPF setting Poor input signal | Reduce Gain Reduce Bass Boost Adjust LPF for smoother blend Check input signal quality from head unit |
| Subwoofer Overheats (Protection LED on) | Insufficient ventilation Overdriving the subwoofer Improper impedance load | Ensure clear airflow around the unit Reduce volume or gain settings Verify speaker impedance (not applicable for this integrated unit, but general troubleshooting) |
9. Specifications
Technical specifications for the Junsun 10-inch Slim Under Seat Subwoofer (Model JS-US-SUB105):
Figure 8: Subwoofer Technical Specifications.
| Parameter | Value |
|---|---|
| Model Name | JS-US-SUB105 |
| Speaker Type | Subwoofer |
| Subwoofer Diameter | 10 Inches |
| Peak Power | 1200W |
| RMS Power | 300W |
| Frequency Response | 20Hz-150Hz |
| THD (Total Harmonic Distortion) | <0.4% |
| Signal-to-Noise Ratio (SNR) | >90dB |
| Low Pass Filter | 50Hz-150Hz |
| Bass Boost | 0 to +12dB |
| Input Sensitivity (High Level) | 0.9V |
| Input Sensitivity (Low Level) | 300mV |
| Fuse Rating | 25A |
| Product Dimensions (L x W x H) | 13.58" x 10.24" x 2.95" (345mm x 260mm x 75mm) |
| Item Weight | 10.52 pounds (4.78 kg) |
| Material | Aluminum |
| Connectivity Technology | Wired |
| Mounting Type | Under-seat |
10. Warranty and Customer Support
The Junsun 10-inch Slim Under Seat Subwoofer comes with a 3-year replacement warranty. For any questions, technical assistance, or support, please contact our dedicated customer service team. Support is available 24/7 to assist you.
For customer service inquiries, please refer to the contact information provided with your purchase or visit the official Junsun website.
