Alpine SWR-1242D Type-R 12" subwoofer with dual 4-ohm voice coils at Crutchfield
Alpine S-W12D4 Car Subwoofer1800W Max, 600W RMS 12" Type-S Series Dual 4 Ohm Car Subwoofer - Walmart.com
Insane Bass From Two 12" Alpine Type R (SWR12D4) Subwoofers!! - YouTube
Alpine SWR-1242D Type-R 12" subwoofer with dual 4-ohm voice coils at Crutchfield
Alpine SWR-1221D 12" Dual 2-ohm Voice Coil Subwoofer at Crutchfield
Alpine Halo R2-Series Dual 12" Voice Coil 4-Ohm Loaded Subwoofer Enclosure Black R2-SB12V - Best Buy
Alpine Type S SWS-12D4 12 Inch 1500 Watt Max 4 Ohm Round Car Audio Subwoofer - Walmart.com
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
Alpine R-W12D4 750W RMS 12" Type R-Series Dual 4-ohm Subwoofer