1. Introduction
The ART 351 is a single-channel, 31-band graphic equalizer designed for precise audio frequency control. It is suitable for a variety of applications including live sound reinforcement, instrument racks, DJ sound systems, and fixed equipment installations. This manual provides detailed instructions for the proper setup, operation, and maintenance of your ART 351 equalizer to ensure optimal performance and longevity.
Key features of the ART 351 include:
- 31-Band 1/3 Octave Graphic Equalizer with Constant-Q Filtering.
- Balanced XLR, Active Balanced 1/4", and Unbalanced RCA Input and Output Connectors for versatile connectivity.
- Variable High-Pass and Low-Pass Filters for precise frequency shaping.
- Selectable +/- 6dB or +/-12dB Level Adjustments for fine-tuning gain.
- 20mm Center Detented Frequency Band Sliders for accurate adjustments.
- Independent Level and Bypass Controls for flexible signal management.
- Rugged All Steel Construction designed for continuous, reliable performance.
2. Product Overview
Figure 2.1: Front panel of the ART 351 EQ 31-Band Graphic Equalizer, showing all controls and indicators.
The front panel of the ART 351 provides all necessary controls for operation and visual feedback. From left to right, you will find the power switch, 31 frequency band sliders, range switch, bypass switch, clip indicator, high-pass filter control, low-pass filter control, and master level control.
Front Panel Controls:
- POWER Switch: Toggles the unit's power on and off.
- Frequency Band Sliders (20Hz - 20kHz): 31 individual sliders, each controlling a specific frequency band. These are center-detented for a flat response when set to the middle position.
- RANGE Switch: Selects the maximum boost/cut range for the frequency sliders, either +/- 6dB or +/- 12dB.
- BYPASS Switch: Engages or disengages the equalizer circuit. When bypassed, the input signal passes directly to the output without equalization.
- CLIP Indicator: Illuminates when the input or internal signal levels are too high, indicating potential distortion.
- HI PASS Control: Adjusts the cutoff frequency for the high-pass filter, allowing frequencies below the set point to be attenuated.
- LOW PASS Control: Adjusts the cutoff frequency for the low-pass filter, allowing frequencies above the set point to be attenuated.
- LEVEL Control: Adjusts the overall output level of the equalizer.
3. Setup
Before connecting the ART 351, ensure all audio equipment is powered off. Proper connection is crucial for optimal performance and to prevent damage to your system.
3.1 Connections:
The ART 351 offers flexible connectivity options:
- XLR Connectors: Use balanced XLR cables for professional audio connections, typically for mixers, power amplifiers, or other studio equipment.
- 1/4" TRS Connectors: Use balanced 1/4" TRS cables for active balanced connections, or unbalanced TS cables for unbalanced connections.
- RCA Connectors: Use unbalanced RCA cables for consumer-level audio equipment or specific DJ setups.
Connect the audio source (e.g., mixer output) to the input of the ART 351. Then, connect the output of the ART 351 to the next component in your audio chain (e.g., amplifier input, recording interface).
3.2 Power Connection:
Connect the supplied power cable to the ART 351's power input and then to a standard AC power outlet. Ensure the power switch on the front panel is in the 'off' position before connecting to power.
4. Operating Instructions
Once connected, you can begin to use the ART 351 to shape your audio. Follow these steps for basic operation:
- Power On: Turn on all connected audio equipment, starting with the ART 351 last.
- Initial Settings:
- Set all 31 frequency band sliders to their center (0dB) detented position.
- Set the RANGE switch to +/- 6dB for finer control, or +/- 12dB for a wider range of adjustment.
- Ensure the BYPASS switch is disengaged (equalizer active).
- Set the HI PASS and LOW PASS controls to their minimum (fully counter-clockwise) and maximum (fully clockwise) positions respectively, to initially disable filtering.
- Set the master LEVEL control to the 0dB position.
- Signal Level Adjustment: Play audio through the system. Observe the CLIP indicator. If it illuminates, reduce the input level to the ART 351 or adjust the master LEVEL control until the CLIP indicator no longer lights up during peak signals.
- Equalization: Adjust the individual frequency band sliders to boost or cut specific frequencies.
- To boost a frequency, move the slider upwards.
- To cut a frequency, move the slider downwards.
- Make small adjustments and listen carefully to the effect on the audio.
- High-Pass and Low-Pass Filters: Use the HI PASS and LOW PASS controls to remove unwanted low-end rumble or high-frequency hiss.
- Turn the HI PASS control clockwise to gradually cut lower frequencies.
- Turn the LOW PASS control counter-clockwise to gradually cut higher frequencies.
- Bypass Function: Use the BYPASS switch to quickly compare the equalized sound with the original, unprocessed signal. This helps in making accurate adjustments.
5. Maintenance
The ART 351 is designed for durability and requires minimal maintenance. Following these guidelines will help ensure its long-term performance:
- Cleaning: Disconnect power before cleaning. Use a soft, dry cloth to wipe the exterior. For stubborn dirt, a slightly damp cloth with mild detergent can be used, followed by a dry cloth. Avoid abrasive cleaners or solvents.
- Ventilation: Ensure adequate airflow around the unit. Do not block ventilation openings.
- Storage: If storing the unit for an extended period, keep it in a cool, dry place away from direct sunlight and extreme temperatures.
- Slider Care: The frequency sliders are robust, but avoid excessive force when adjusting them.
6. Troubleshooting
This section addresses common issues you might encounter with your ART 351 equalizer.
| Problem | Possible Cause | Solution |
|---|---|---|
| No audio output. | Incorrect connections, unit not powered, bypass engaged, level control too low. | Check all cable connections. Ensure the unit is powered on. Disengage the BYPASS switch. Increase the master LEVEL control. |
| Distorted audio / CLIP indicator lit. | Input signal too high. | Reduce the output level from the preceding device in the audio chain, or slightly decrease the master LEVEL control on the ART 351. |
| Hum or buzzing noise. | Ground loop, faulty cable, interference. | Ensure all equipment is properly grounded. Try using a ground lift adapter if necessary (only if safe and recommended by an audio professional). Check and replace any suspect cables. Ensure power cables are not running parallel to audio cables. |
| Equalizer not affecting sound. | BYPASS switch engaged. | Disengage the BYPASS switch. |
If the problem persists after attempting these solutions, please contact ART customer support for further assistance.
7. Specifications
| Feature | Specification |
|---|---|
| Model Number | 351 |
| Channels | Single-channel |
| Bands | 31 bands, 1/3 Octave |
| Filter Type | Constant-Q Filtering |
| Level Adjustment Range | Selectable +/- 6dB or +/- 12dB |
| Input/Output Connectors | Balanced XLR, Active Balanced 1/4", Unbalanced RCA |
| Filters | Variable High-Pass and Low-Pass Filters |
| Item Weight | 6.55 pounds (2.97 kg) |
| Product Dimensions (L x W x H) | 21.3 x 10.4 x 3.5 inches (54.1 x 26.4 x 8.9 cm) |
| Construction | Rugged All Steel Construction |
8. Warranty and Support
The ART 351 EQ 31-Band Graphic Equalizer is designed for reliable performance. It typically comes with a one-year limited warranty from the date of purchase, covering defects in materials and workmanship. Please refer to the warranty card included with your product for specific terms and conditions, as warranty details may vary by region and retailer.
For technical support, service, or warranty claims, please contact ART customer service. You can usually find contact information on the manufacturer's official website or on the product packaging. When contacting support, please have your product model number (351) and purchase information readily available.
