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" Dual 4-Ohm Car Component Subwoofer – DiscountCentralOnline
PIONEER TS-W3003D4 12" 2000W MAX CHAMPION PRO DUAL 4 OHMS SUBWOOFER CAR SUB - Walmart.com
Pioneer TS-W3003D4 12" Champion Pro Series 2000W Subwoofer