TUrboSOund SD21 21 inch Subwoofer - 2000 watts Power – SpeakersAndAmps.com
Amazon.com: H YANKA 10 Inch Subwoofer - 10 Inch Paper Cone Subwoofer Car Audio, Black Steel Basket, Dual Voice Coil 2 Ohm Impedance 10 subwoofer, 1200W MAX Power 10 inch Competition Subwoofer : Electronics