Amazon.com: Alpine W10S4 10" 750 Watt Peak 250 Watt RMS 4-Ohm Car Audio Subwoofer Sub : Electronics
Amazon.co.jp: ALPINE SWE-2500-AV Alphard/Vellfire 30 Series (H27/1 - Current H30/1 After Minor Changes) Subwoofer, 9.8 inches (25 cm) Back Door : Automotive