Infinity

A passive subwoofer, which means no power cord, no built-in amplifier and no electronic crossover to fail. Two 6.5-inch polypropylene woofers in a bandpass box, 40 to 150Hz, wired high-level — your amplifier's front outputs go in, your main speakers come off the pass-through, and the sub keeps everything below about 150Hz. Twenty-eight pounds of moulded composite. Very good condition.