Alpine SWR-1223D Type-R 12" subwoofer with dual 2-ohm voice coils at Crutchfield
Alpine R-W12D2, R Series 12" Dual 2 Ohm Voice Coil Subwoofer - 2250 Wa – AVLeaderz
Alpine Halo R2-Series 12" Dual Voice Coil 4-Ohm Loaded Subwoofer Enclosure Black R2-SB12V - Best Buy
Amazon.com: Alpine ALP19-R-W12D2x2wKit Car Audio Type R Dual 2 Ohm 1500 Watt 12" Subwoofers with Sub Install Kit and HA-SWKD Dual Sub Box Install Kit - 16 Screws and Speaker Wire with
Single alpine type r 12" ripping car apart - YouTube