Amazon.com: Alphasonik AS12DF 12" 1500 Watts 4-Ohm Down Fire Shallow Mount Flat Enclosed Sub woofer for Tight Spaces in Cars and Trucks, Slim Thin Loaded Subwoofer Air Tight Sealed Bass Enclosure :
Amazon.com: KICKER TRTP 12-inch (30cm) Thin Down Firing Subwoofer and Passive Radiator Enclosure, 2-Ohm, RoHS Compliant : Electronics
Amazon.com: Alphasonik AS10DF 10" 1200 Watts 4-Ohm Down Fire Shallow Mount Flat Enclosed Sub woofer for Tight Spaces in Cars and Trucks, Slim Thin Loaded Subwoofer Air Tight Sealed Bass Enclosure :
Amazon.com: KICKER CVTDF 10" (25cm) Subwoofer in Down Firing Encl, 2-Ohm; RoHS Compliant : Electronics