1. Introduction
Thank you for choosing the BLAUPUNKT GTHS-81PRO 8-inch Amplified Subwoofer. This compact, active subwoofer system is designed to enhance your vehicle's audio experience by providing powerful and clear low-frequency bass. With its integrated amplifier and flat design, it offers a convenient solution for adding bass without occupying significant space.
This manual provides essential information for the proper installation, operation, and maintenance of your GTHS-81PRO subwoofer. Please read it thoroughly before installation and use to ensure optimal performance and safety.
2. Safety Information
- Professional Installation Recommended: For optimal safety and performance, it is recommended that this product be installed by a qualified car audio technician.
- Power Source: Connect the subwoofer only to a 12V DC negative ground electrical system.
- Wiring: Ensure all wiring is securely connected and properly insulated to prevent short circuits and electrical hazards. Use appropriate gauge wiring as specified in the installation section.
- Fuse Protection: Always install the recommended fuse (15A) close to the vehicle's battery on the main power wire.
- Mounting: Securely mount the subwoofer to prevent it from becoming a projectile during sudden stops or accidents. Avoid mounting in locations that obstruct vehicle controls or airbags.
- Heat Dissipation: Ensure adequate ventilation around the subwoofer to prevent overheating. Do not cover the unit.
- Volume Levels: Prolonged exposure to high volume levels can cause hearing damage. Adjust volume to a comfortable level.
3. Package Contents
Verify that all items are present in the package:
- BLAUPUNKT GTHS-81PRO Amplified Subwoofer
- Wired Remote Level Control
- Wiring Harness (Power, Ground, Remote, High-Level Input)
- Mounting Hardware (Brackets, Screws)
- Instruction Manual
Image: BLAUPUNKT GTHS-81PRO subwoofer with included accessories, including the wired remote, wiring harness, mounting hardware, and the instruction manual.
4. Product Overview
The BLAUPUNKT GTHS-81PRO is a compact, self-contained amplified subwoofer unit. It features an 8-inch subwoofer driver and an integrated amplifier, all housed within a durable aluminum enclosure. The control panel, located on one side, provides access to all necessary connections and adjustments.
Image: Top-down view of the BLAUPUNKT GTHS-81PRO amplified subwoofer, highlighting the speaker grille, the control panel with various inputs, fuse, power terminals, and the separate wired remote level control unit.
Control Panel Features:
- Power/Protect LED: Indicates power status (green for power, red for protection mode).
- Gain Control: Adjusts the input sensitivity of the amplifier.
- Low Pass Filter (LPF): Adjusts the upper frequency limit of the subwoofer.
- Phase Switch (0°/180°): Adjusts the phase of the subwoofer output relative to the main speakers.
- Bass Boost: Provides an adjustable bass enhancement at a specific frequency.
- RCA Low-Level Inputs: For connecting to a head unit with RCA pre-outs.
- High-Level Inputs: For connecting to speaker outputs from a head unit without RCA pre-outs.
- Remote Level Control Port: For connecting the wired remote control.
- Fuse Holder: Contains the 15A fuse for protection.
- Power Terminals (+12V, REM, GND): Connections for power, remote turn-on, and ground.
5. Setup and Installation
Proper installation is crucial for the performance and longevity of your subwoofer. If you are unsure about any steps, consult a professional installer.
5.1 Mounting Location
The compact design of the GTHS-81PRO allows for flexible mounting. Ideal locations include:
- Under a car seat
- In the trunk
- Behind a truck seat
Ensure the chosen location provides adequate ventilation and does not interfere with vehicle operation or safety features. Use the provided mounting hardware to secure the unit firmly.
Image: Dimensional diagram of the BLAUPUNKT GTHS-81PRO subwoofer, indicating its length of 13 inches (330mm), width of 9.45 inches (240mm), and height of 2.87 inches (73mm).
5.2 Wiring Connections
Before making any connections, disconnect the vehicle's negative battery terminal to prevent electrical shorts.
- Power (+12V): Run a power cable (minimum 8 AWG recommended) directly from the vehicle's positive battery terminal to the +12V terminal on the subwoofer. Install a 15A fuse holder within 18 inches (45 cm) of the battery.
- Ground (GND): Connect a ground cable (minimum 8 AWG recommended) from the GND terminal on the subwoofer to a clean, unpainted metal surface of the vehicle's chassis. Ensure a good electrical connection.
- Remote Turn-On (REM): Connect a remote turn-on wire from your head unit's remote output (typically a blue/white wire) to the REM terminal on the subwoofer. If your head unit does not have a remote output, the subwoofer can use its high-level input signal sensing to turn on automatically.
- Audio Input:
- Low-Level Input (RCA): If your head unit has RCA pre-outs, connect RCA cables from the head unit's subwoofer or full-range outputs to the RCA inputs on the GTHS-81PRO.
- High-Level Input (Speaker Level): If your head unit does not have RCA pre-outs, connect the speaker wires from your head unit's front or rear speaker outputs to the high-level input harness provided with the subwoofer.
- Remote Level Control: Connect the wired remote level control to the designated port on the subwoofer. Route the cable to a convenient location for adjustment from the driver's seat.
Once all connections are made, reconnect the vehicle's negative battery terminal.
6. Operating Instructions
After installation, follow these steps to configure your subwoofer for optimal sound.
- Initial Settings: Set the Gain control to minimum, LPF to approximately 80Hz, Bass Boost to 0dB, and Phase to 0°.
- Power On: Turn on your vehicle's audio system. The Power LED on the subwoofer should illuminate green.
- Adjust Gain: Play a music track with strong bass. Slowly increase the Gain control on the subwoofer until you hear distortion, then back it off slightly until the sound is clear. The goal is to match the subwoofer's output level with your main speakers.
- Adjust Low Pass Filter (LPF): Adjust the LPF to blend the subwoofer's output seamlessly with your main speakers. A common starting point is 80-100Hz. If your main speakers are small, you might set the LPF higher; if they are large, you might set it lower.
- Adjust Phase: While playing music, switch the Phase control between 0° and 180°. Choose the setting that provides the most impactful and cohesive bass response. This often depends on the subwoofer's placement relative to the main speakers.
- Adjust Bass Boost: Use the Bass Boost control sparingly to add a subtle enhancement to the bass if desired. Excessive bass boost can lead to distortion and potential damage.
- Remote Level Control: Use the wired remote control for convenient real-time adjustment of the subwoofer's output level from your driving position.
7. Maintenance
The BLAUPUNKT GTHS-81PRO is designed for durability and requires minimal maintenance.
- Cleaning: Use a soft, dry cloth to clean the exterior of the unit. Do not use harsh chemicals or abrasive cleaners.
- Connections: Periodically check all wiring connections to ensure they are secure and free from corrosion.
- Ventilation: Ensure that the area around the subwoofer remains clear to allow for proper heat dissipation.
- Fuse Replacement: If the fuse blows, replace it only with a fuse of the same type and rating (15A). Using a fuse with a higher rating can cause damage to the unit or vehicle's electrical system.
8. Troubleshooting
If you experience issues with your subwoofer, refer to the following troubleshooting guide:
| Problem | Possible Cause | Solution |
|---|---|---|
| No Power (Power LED off) | Blown fuse; Loose power/ground connection; No remote turn-on signal. | Check and replace fuse; Verify all power, ground, and remote connections; Ensure head unit is providing remote signal or use high-level input auto-sense. |
| Subwoofer in Protection Mode (Protect LED red) | Overheating; Short circuit in speaker wiring; Low voltage. | Allow unit to cool; Check speaker wiring for shorts; Verify stable 12V power supply. |
| No Sound from Subwoofer | No audio input signal; Gain set too low; LPF set too low; Phase incorrect. | Check RCA/high-level input connections; Increase Gain; Adjust LPF; Experiment with Phase switch. |
| Distorted Sound | Gain set too high; Bass Boost too high; Poor quality audio input. | Reduce Gain; Reduce Bass Boost; Check audio source and input cables. |
| Weak or Muffled Bass | Gain too low; LPF too low; Phase incorrect; Subwoofer placement. | Increase Gain; Adjust LPF higher; Experiment with Phase switch; Try different mounting locations. |
9. Specifications
Technical specifications for the BLAUPUNKT GTHS-81PRO amplified subwoofer:
| Feature | Specification |
|---|---|
| Speaker Size | 8 Inches (203.2 mm) |
| Maximum Output Power | 320 Watts |
| RMS Power | 115 Watts |
| Frequency Response | 20 Hz - 150 Hz |
| Signal-to-Noise Ratio (S/N) | 91 dB |
| Impedance | 4 Ohm |
| Bass Boost | 0 to +12 dB |
| Phase Selector | 0° / 180° |
| Input Sensitivity (Low Level) | 150 mV - 6 V |
| Input Sensitivity (High Level) | 1 V - 8 V |
| Fuse Rating | 15 Amp |
| Dimensions (L x W x H) | 13 in. x 9.45 in. x 2.87 in. (330mm x 240mm x 73mm) |
| Material | Aluminum |
| Connectivity Technology | Wired (RCA) |
| Control Method | App (Note: Wired remote control is included for direct level adjustment) |
Image: Detailed specifications for the BLAUPUNKT GTHS-81PRO subwoofer, including output power, frequency, S/N ratio, phase adjustment, bass boost range, operating voltage, fuse rating, and impedance.
10. Warranty and Support
The BLAUPUNKT GTHS-81PRO comes with a limited warranty. Please refer to the warranty card included in your package for specific terms and conditions, including coverage duration and limitations.
For technical support, troubleshooting assistance, or warranty claims, please contact BLAUPUNKT customer service through their official website or the contact information provided with your product documentation.