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 Champion Series PRO TS-W3003D4 12" subwoofer with dual 4-ohm voice coils at Crutchfield