Amazon.com: Gravity 2X 8 Inch 1000 Watt Car Audio Subwoofer w/ 4 Ohm DVC Power 8' Sub Pair - Feature Dual Voice Coil, Thick Magnet, Design for Car, ATV, Van, High Performance
Amazon.com: MB Quart DS1-204 Discus Shallow Mount Subwoofer (Black) – 8 Inch Subwoofer, 400 Watt, Car Audio, 2 Inch Voice Coils, UV Rubber Surround, Best in Sealed Enclosures : Electronics
Sundown Audio Xv4 8" inch DVC Dual 2 Ohm 1000 Watt (X Series) Car Subwoofer
Kenwood Excelon KFC-XW800F Shallow-mount 8" 4-ohm subwoofer at Crutchfield