Pioneer TS-A2000LD2 Shallow-mount 8" subwoofer with dual 2-ohm voice coils at Crutchfield
Pioneer TSW312D4 Champion Series 12" 1500 Watt Dual 4 Ohm Voice Coil DVC Car Subwoofer - Walmart.com
Pioneer TS-W312D4 | Car Entertainment, Subwoofers, Champion Series Subwoofer, Champion Series Red Subwoofer | Pioneer Middle East - Car Stereo, Car Subwoofer, Amplifier
Pioneer TS-W259D4 Champion Series 10" subwoofer with dual 4-ohm voice coils at Crutchfield