Best Buy: Pioneer 12" Dual-Voice-Coil 2-Ohm Subwoofer TS-W307D2
2014 Pioneer Champion Series PRO Subwoofer - YouTube
TS-W3002D2|D4 - 12" Champion Series PRO Subwoofer with 3500 Watts Max. (1000 Watts Nom.) | Pioneer Electronics USA
Amazon.com: Pioneer TS-A300D4 12 Inch 1500 Watts Max Power Dual 4-Ohm Voice Coil A Series Car Audio Stereo Subwoofer Loudspeakers / Free Alphasonik Earbuds : Electronics
Pioneer TS-300D4 12" 30cm Champion Series Dual Voice Coil Car Subwoofer 1400W 884938373654 | eBay
Pioneer TSW312D4 Champion Series 12" 1500 Watt Dual 4 Ohm Voice Coil DVC Car Subwoofer - Walmart.com