The 452 PBM powered subwoofer incorporates a specially designed 325 watt high current, all discreet Class G linear power amplifier. The amplifier, voice coil charactersitics, and cabinet dimensions were optimized to work together to provide deep, well defined bass at very low frequencies. The cabinet is heavily braced internally to prevent undesirable cabinet vibrations. The 452 PBM high performance home theater speaker system that meets both the strict certification standards of THX and the digital demands of Dolby Digital and DTS.