The TS18C is the only internally cross-overed passive subwoofer in the Pulse line. Bi-amping is of course an option, but not a necessity due to an internel 150Hz low-pass network. With power handling of 350 watts, the TS18C may be used independently or in parallel with mains. A single, custom designed cast frame 18" speaker assures tight control and excellent linear response. With a lighter weight and more compact size than many other 18 inch subwoofers, the TS18C is an excellent choice when you want Pulse quality, performance and appearance in a passive subwoofer.