Alto TS18S 2500 Watt Powered Subwoofer - 18"Rock Solid Sound from the Bottom, Up The best performances need the best in sound reinforcement at all ends of the sonic spectrum. For tight, punchy low end look no further than the Alto Professional TS18S powered subwoofer. When added to your full range speaker setup, the TS18S subwoofer delivers powerful but controlled low end presence to your PA configuration for a full and complete listening experience for the modern public music space. With a