STLF-1504-8 | 15" 450W Raw Subwoofer Replacement w/ 4" Voice Coil, 8-ohm – Sound Town
Epique E150HE-44 5-1/2" DVC MMAG Extended Range Subwoofer 4 Ohm per Coil
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