Monoprice Monolith THX Ultra Certified 2000 Watt Powered Subwoofer (Model 141496) User Manual

1. Introduction

Thank you for purchasing the Monoprice Monolith THX Ultra Certified 2000 Watt Powered Subwoofer. This high-performance 13-inch subwoofer is engineered to deliver exceptional bass output, low distortion, and reference-level audio for both studio and home theater environments. This manual provides essential information for the safe and optimal installation, operation, and maintenance of your subwoofer. Please read it thoroughly before use and retain it for future reference.

2. Important Safety Instructions

WARNING: To reduce the risk of electric shock, do not remove the cover. No user-serviceable parts inside. Refer servicing to qualified personnel.

• Read these instructions carefully.
• Keep these instructions for future reference.
• Heed all warnings.
• Follow all instructions.
• Do not use this apparatus near water.
• Clean only with a dry cloth.
• Do not block any ventilation openings. Install in accordance with the manufacturer's instructions.
• Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat.
• Do not defeat the safety purpose of the polarized or grounding-type plug. A polarized plug has two blades with one wider than the other. A grounding-type plug has two blades and a third grounding prong. The wide blade or the third prong are provided for your safety. If the provided plug does not fit into your outlet, consult an electrician for replacement of the obsolete outlet.
• Protect the power cord from being walked on or pinched, particularly at plugs, convenience receptacles, and the point where they exit from the apparatus.
• Only use attachments/accessories specified by the manufacturer.
• Use only with the cart, stand, tripod, bracket, or table specified by the manufacturer, or sold with the apparatus. When a cart is used, use caution when moving the cart/apparatus combination to avoid injury from tip-over.
• Unplug this apparatus during lightning storms or when unused for long periods of time.
• Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way, such as power-supply cord or plug is damaged, liquid has been spilled or objects have fallen into the apparatus, the apparatus has been exposed to rain or moisture, does not operate normally, or has been dropped.

3. What's in the Box

Please inspect the contents of the package to ensure all items are present and undamaged. If any items are missing or damaged, contact Monoprice Customer Service immediately.

• Monoprice Monolith THX Ultra Certified 2000 Watt Powered Subwoofer
• Power Cord
• Foam Port Plugs (3 included)

4. Key Features

• THX Ultra Certified: This subwoofer has undergone rigorous testing by THX engineers to ensure it meets the highest standards for audio performance, capable of achieving THX Reference Level volumes without audible distortion. It is designed for large rooms up to 3,000 cubic feet.
  

  Image: THX Ultra Certified badge, indicating high performance standards.
• 13-Inch High-Excursion Woofer: Features a newly designed 13-inch driver with a hybrid cone (long fiber pulp and fiberglass) for optimal motion, high output, low distortion, and accurate bass reproduction.
  

  Image: Graphic indicating a 13-inch woofer size.

• 2000 Watt (RMS) Amplifier: A powerful Class D amplifier (3800+ watt peak) with a Texas Instruments DSP engine ensures precise control, power output limiting, and thermal protection, customized for the driver.
  

  Image: Graphic indicating 2000 Watts of amplifier power.

• Robust Cabinet Design: Constructed from HDF material with massive internal bracing, the cabinet minimizes resonance. It features three ports that can be configured using foam plugs for sealed, semi-sealed, or ported operation.
  

  Image: Cutaway view of the subwoofer cabinet, highlighting the internal structure, driver, and three port tubes.

5. Setup and Installation

5.1 Unpacking and Placement

Due to the subwoofer's weight (approximately 100 lbs), it is recommended that two people handle the unit during unpacking and placement.

• Carefully remove the subwoofer from its packaging.
• Place the subwoofer on a stable, level surface. Consider its dimensions (29.1"D x 20.3"W x 23.8"H) when choosing a location.
• For optimal bass performance, experiment with different placements in your room. Corner placement often provides the most output, while placement along a wall can offer a more balanced response.
• Ensure adequate ventilation around the amplifier panel at the rear of the unit.

Image: Front view of the Monolith 13-inch subwoofer with its driver and three front-firing ports visible.

Image: Diagram showing the dimensions of the Monolith 13-inch subwoofer: 29.1 inches deep, 20.3 inches wide, and 23.8 inches high.

5.2 Connections

Before making any connections, ensure the subwoofer's power switch is in the OFF position and the power cord is unplugged from the wall outlet.

Image: Rear panel of the Monolith subwoofer, displaying various controls (Crossover, Phase, Level) and input/output connections (RCA, XLR).

• RCA Inputs: Connect an RCA cable from the LFE (Low-Frequency Effects) output of your AV receiver or pre-amplifier to the LFE input on the subwoofer. If your receiver has stereo pre-outs, use both Left and Right RCA inputs on the subwoofer.
• XLR Inputs: For professional installations or longer cable runs, use balanced XLR cables from your compatible audio source to the XLR inputs on the subwoofer.
• Power Connection: Once all audio connections are made, connect the supplied power cord to the subwoofer's AC inlet and then to a grounded wall outlet.

5.3 Initial Power On

• Flip the power switch on the rear panel to the ON position.
• The subwoofer should power on, indicated by an LED.
• Begin with the "Level" control set to its minimum position.
• Proceed to the "Operating" section for initial calibration.

6. Operation and Adjustment

6.1 Rear Panel Controls

The rear panel of your Monolith subwoofer features several controls for fine-tuning its performance to your listening environment and main speakers.

Image: Detailed view of the subwoofer's rear panel, showing the Crossover, Phase, and Level knobs, along with input/output jacks.

• Level (Volume) Control: Adjusts the output volume of the subwoofer. Start low and gradually increase until the bass blends seamlessly with your main speakers.
• Crossover Frequency Control: Determines the highest frequency the subwoofer will reproduce. If using an AV receiver with bass management, set this to LFE or bypass. If connecting directly to a stereo pre-amp, adjust this to match the low-frequency rolloff of your main speakers (typically between 80Hz and 120Hz).
• Phase Control: Adjusts the phase of the subwoofer's output relative to your main speakers. Experiment with 0° and 180° settings to find the position that provides the most impactful and coherent bass at your listening position.
• Mode Switch (Ported/Sealed/Semi-Sealed): Your subwoofer comes with three foam port plugs.
  • Ported Mode: All three ports open (no plugs). Provides maximum output and extension, ideal for home theater.
  • Sealed Mode: All three ports plugged. Offers tighter, more controlled bass, often preferred for critical music listening.
  • Semi-Sealed Mode: One or two ports plugged. Provides a balance between output and control.

  To change modes, gently insert or remove the foam plugs from the front ports. Ensure the subwoofer is powered off before inserting or removing plugs.

6.2 System Calibration

For optimal performance, it is highly recommended to use your AV receiver's automatic room correction system (e.g., Audyssey, MCACC, YPAO, Dirac Live) after initial setup. This will calibrate the subwoofer's level, phase, and crossover settings to your room's acoustics.

7. Maintenance

• Cleaning: Dust the subwoofer cabinet with a soft, dry cloth. Do not use liquid cleaners, aerosols, or abrasive materials, as they may damage the finish.
• Ventilation: Ensure the rear amplifier panel's ventilation openings remain clear of obstructions to prevent overheating.
• Storage: If storing the subwoofer for an extended period, unplug it from the power outlet and store it in a cool, dry place, preferably in its original packaging.

8. Troubleshooting

9. Specifications

10. Warranty Information

This Monoprice Monolith subwoofer comes with a Limited Warranty. For specific details regarding the duration and terms of your warranty, please refer to the warranty documentation included with your purchase or visit the official Monoprice website.

Optional protection plans may be available for purchase, offering extended coverage. Please check with your retailer for details on available protection plans.

11. Customer Support

For technical support, troubleshooting assistance, or warranty inquiries, please contact Monoprice Customer Service.

• Website: www.monoprice.com
• Contact Information: Refer to the "Contact Us" section on the Monoprice website for phone numbers and email support.