Pioneer Champion TS-W3003D4 Woofer, 600 W RMS, 2000 W PMPO, 1 Pack - Walmart.com
Crunch Crw12d4 12 Inch 800 Watt Max 4 Ohm Dual Voice Coil Car Subwoofer Speaker With 2 Channel 1000 Watt Amp A/b Class Car Audio Stereo Amplifier : Target
Pioneer W/1000 Subwoofer 12 Inch Driver | eBay
Pioneer TS-SW2541D 10" 4-ohm shallow subwoofer at Crutchfield