Introduction
The Gravity GR-EQP11 is a 1/2 DIN 4-way car parametric equalizer and sound processor designed to provide advanced audio control for your vehicle's sound system. This unit allows for precise adjustment of audio frequencies, features a digital bass enhancement circuit, and includes dedicated outputs for front, rear, and subwoofer channels. Its design incorporates night illumination for visibility in low-light conditions.
1. Installation and Wiring
Proper installation is crucial for optimal performance and safety. It is recommended that installation be performed by a qualified professional.
1.1 Mounting the Equalizer
The GR-EQP11 is a 1/2 DIN unit, designed to fit into standard car audio slots or be mounted under the dashboard. Ensure the mounting location allows for adequate ventilation and easy access to controls.
Image: Side view of the Gravity GR-EQP11 equalizer, illustrating its compact dimensions for installation.
1.2 Wiring Connections
Connect the equalizer to your car's electrical system and audio components as follows:
- Power (BATT+): Connect to a constant +12V power source from the car battery. Use an inline fuse (not included) for protection.
- Ground (GND): Connect to a clean chassis ground point in the vehicle. Ensure a secure connection to prevent noise.
- Remote (REMOTE): Connect to the remote turn-on lead from your head unit. This will turn the equalizer on and off with your car stereo.
- Audio Input (CD/AUX): Connect your head unit's RCA outputs to either the CD or AUX input on the equalizer. The unit supports both.
- Audio Output (FRONT, REAR, SUB): Connect the equalizer's RCA outputs to the corresponding inputs on your amplifier(s).
Image: Rear panel of the GR-EQP11, detailing the RCA input/output connections and power terminals.
2. Operation
The GR-EQP11 offers a range of controls for fine-tuning your audio experience.
Image: Front panel controls of the GR-EQP11, including volume, fader, subwoofer, and equalizer adjustments.
2.1 Master Controls
- VOLUME Control: This knob adjusts the overall output level of the equalizer. It can provide up to 9 Volts RMS of output, allowing for strong signal delivery to your amplifiers. Rotate clockwise to increase volume, counter-clockwise to decrease.
- FADER Control: Use this control to balance the audio output between the front and rear speaker channels.
- INPUT Selector (CD/AUX): This switch allows you to select between two stereo RCA input sources: CD or AUX. Ensure the correct input is selected for your audio source.
2.2 Equalizer Controls
The GR-EQP11 features a 4-band parametric equalizer, enabling detailed frequency adjustments. Each band offers up to 12dB of boost or cut, allowing you to tailor the sound profile to your vehicle's acoustics and personal preference.
- BASS (40Hz): Adjusts the lowest audio frequencies.
- MID-BASS (200Hz): Adjusts the lower-midrange frequencies.
- MID (2KHz): Adjusts the primary midrange frequencies.
- HIGH (20KHz): Adjusts the highest audio frequencies.
2.3 Subwoofer Controls
- SUB Level Control: This dedicated knob adjusts the output level of the subwoofer channel independently from the main volume.
- LOWPASS FREQ Selector (60Hz/120Hz): This switch sets the low-pass crossover frequency for the subwoofer output. Select 60Hz for a tighter, deeper bass response, or 120Hz for a broader range of low frequencies to be sent to the subwoofer.
2.4 Sub Effect (Digital Bass Machine)
The integrated digital bass machine enhances low-frequency response, adding depth and impact to your audio.
- ON/OFF Switch: Toggles the bass enhancement circuit on or off.
- WIDE Control: Adjusts the bandwidth of the bass effect, influencing how broad the affected frequency range is.
- SWEEP Control: Adjusts the center frequency of the bass enhancement, allowing you to target specific low frequencies.
- LEVEL Control: Controls the intensity or amount of the bass effect applied.
Experiment with these controls to achieve the desired bass impact without distortion.
3. Maintenance
The Gravity GR-EQP11 requires minimal maintenance to ensure long-lasting performance.
- Cleaning: Use a soft, dry cloth to wipe the unit's surface. Avoid abrasive cleaners or solvents.
- Connections: Periodically check all wiring connections (power, ground, remote, RCA) to ensure they are secure and free from corrosion. Loose connections can lead to noise or intermittent operation.
- Ventilation: Ensure the unit's mounting location allows for proper airflow to prevent overheating.
4. Troubleshooting
If you encounter issues with your GR-EQP11, refer to the following common problems and solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| No Power | Blown fuse, loose power/ground/remote wire, no remote signal. | Check inline fuse. Verify all power, ground, and remote connections are secure. Ensure head unit is providing a remote turn-on signal. |
| No Sound | Incorrect input selection, loose RCA connections, amplifier not powered. | Confirm correct input (CD/AUX) is selected. Check all RCA cables for secure connection. Ensure amplifier is powered on and functioning. |
| Distorted Sound | Input gain too high, equalizer settings overdriven, damaged speakers/amplifier. | Reduce the volume level on the equalizer or head unit. Adjust EQ bands to avoid excessive boost. Check speakers and amplifier for damage. |
| Engine Noise / Alternator Whine | Poor grounding, power wire too close to RCA cables, faulty components. | Ensure ground connection is clean and secure. Reroute power cables away from RCA cables. Consider a ground loop isolator if the problem persists. If experiencing noise, firmly press and turn the volume control knob down and then back up, as this has resolved the issue for some users. |
5. Specifications
Key technical specifications for the Gravity GR-EQP11:
- Model: GR-EQP11
- Type: 1/2 DIN 4-Way Parametric Equalizer & Sound Processor
- Output Voltage: Up to 9 Volts RMS
- Equalizer Bands: 4 (Bass, Mid-Bass, Mid, High)
- Boost/Cut: +/- 12dB per band
- Lowpass Frequencies: 60Hz / 120Hz (selectable)
- Power Supply: On-board 30V Bipolar Switching Power Supply
- Input/Output Connectors: Gold-Plated RCA
- Dimensions (Product): 7.7 x 9 x 1.7 inches (Length x Width x Height)
- Weight (Item): 1.7 pounds
- Illumination: Night Illumination Design
Image: Dimensions of the GR-EQP11 unit, indicating its physical size for installation planning.
6. Warranty Information
Gravity products are designed for reliability and performance. For specific warranty terms and conditions, please refer to the documentation included with your purchase or contact Gravity customer support. Typically, a limited warranty covers manufacturing defects for a specified period from the date of purchase.
7. Customer Support
For technical assistance, troubleshooting beyond this manual, or warranty inquiries, please contact Gravity customer support. Visit the official Gravity website for contact information and additional resources.