Monolith™ by Monoprice™12' THX® Certified Ultra 500‑Watt Powered SubwooferMassive Output. Low Distortion. THX® Certified.The Monolith™ THX® Certified Ultra Subwoofer sets the standard for bass output, low distortion, and affordability. With chest thumping bass that plays down to well under 20Hz, the Monolith subwoofer unleashes cinema level volume, with the ability to convey and articulate the subtle nuances of music. The Monolith subwoofer cabinets have been redesigned for a sleeker look, rounded edges, and an inset subwoofer for a better aesthetic appearance. THX® Certified Ultra12' Woofer500‑Watt Amplifier THX® Certified Ultra: THX® engineers completed hundreds of different scientific tests to ensure the highest audio performance possible. The tests ensure the speaker can reach the high volumes necessary to achieve THX Reference Level without creating audible distortion or artifacts. THX® Certified Ultra products are for large sized rooms, up to 3,000 cubic feet in size, with a 10~12 foot viewing distance from the screen.12' Woofer: The Monolith™ 12' driver was developed from the ground up, with a design focus on achieving output, accuracy, dynamics, and linearity, while minimizing distortion. Enclosed in a cabinet made from HDF material, massive internal bracing, and outfitted with a single port that can utilize a foam plug to run the subwoofer in a sealed mode.500 Watt Amplifier: The 500W RMS amplifier is built around a Texas Instruments® 48‑bit data path (with 28‑bit filter coefficients) and DSP engine. Each amplifier's transfer function, power output limiting, and thermal protection are monitored to the millisecond and are customized for each individual driver. The high efficiency Class D amplifier modules are based on a proven topology that has been continuously refined over the past 4 years. The amplifier has vast reserves of power for highly accurate, deep bass for your home theater or music system. For almost 40 years, THX has set the standard for the audio and visual fidelity of entertainment experiences. THX Certification is a globally recognized assurance of uncompromising quality, consistency and performance. We blend art, technology, and the dynamics of real world listening and viewing environments to ensure products deliver the artist's true vision.THX CertificationUsing industry standards and a proprietary testing methodology, THX engineers evaluate and certify the audio and visual fidelity of consumer electronics to ensure they deliver the optimal entertainment experience. In cinemas, at home, and on‑the‑go, your entertainment comes alive with THX.Certification Process.