Polk HTS subwoofers integrate our patented Power Port® technology, which smooths airflow as it exits the speaker to provide louder, cleaner bass than traditional ported subwoofer designs. Pair the HTS 12 with any of your Polk speakers for that deep bass impact you can feel across all your home theatre and music needs. Built-in controls for variable volume, low pass filter and phase (0/180°) for optimum bass levels. Set power toggle to Auto on/off or DC control (12V trigger) for fast and easy on/off power switching in the sub and other home theatre equipment—all easily accessible on the back panel. Connect via LFE (unfiltered / low pass disabled) or stereo line level RCA inputs—complements any home theatre system (cables not included).