Pioneer Electronics on Twitter: "The Champion Series Subwoofers feature an enclosed basket structure that is designed to support the steel basket by reducing the spread of vibration that causes bass loss frequency. #
Pioneer TS-W3003D4 12" Champion Series Pro Subwoofer With 2000 Watts Max Power - Dual 4 ohm
Amazon.com: 4) Pioneer 12" 2000W Champion Car Power Subwoofers 4-Ohm DVC Subs | TS-W3003D4 : Electronics
Pioneer TS-W3003D4 12" Champion Pro Series 2000W Subwoofer