Amazon.com: Skar Audio VXF-12 D2 12" 3000 Watt Max Power Dual 2 Ohm Competition Car Subwoofer : Electronics
Amazon.com: H YANKA 12 Inch Subwoofer - 12 Inch Paper Cone Subwoofer Car Audio, Black Steel Basket, Dual Voice Coil 4 Ohm Impedance 12 subwoofer, 1600W MAX Power 12 inch Competition Subwoofer : Electronics