Pioneer 12" Single-Voice-Coil Subwoofer with Enclosure Black TSSWX3002 - Best Buy
Pioneer TS-A120B Ported enclosure with one A-Series 12" 2-ohm subwoofer at Crutchfield
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
2 x Pioneer TS-W312D4 12" Car Dual 4-ohm Woofer + QPower QBOMB Dual Sub Box | eBay