The ThunderBass TB-18 is a high-output powered subwoofer with an 18-inch long-throw woofer and a 1000W Class D amplifier. Delivering bass frequencies down to 18Hz, it is the ultimate foundation for home theater systems demanding maximum impact. The variable low-pass crossover from 40Hz to 120Hz ensures seamless integration with any main speakers. With auto power-on sensing and balanced XLR inputs, setup is fast and performance is overwhelming.