2) Alpine Type R 12 Inch 2250 Watt Max 4 Ohm Round Car Audio Subwoofer - Walmart.com
Alpine R-Series Dual 8" Voice Coil 4-Ohm Subwoofer Black R2-W8D4 - Best Buy
Alpine RS-W12D4 R-Series shallow-mount 12" subwoofer with dual 4-ohm voice coils at Crutchfield
Alpine R-Series R2-W10D4 10 Inch Dual 4-Ohm Voice Coils Subwoofer with 750W RMS
Alpine Type R 12 Inch 2250 Watt Max 4 Ohm Round Car Audio Subwoofer | R-W12D4 - Walmart.com
Universal Car Stereo Slotted S Port Single 10" Alpine Bundle Type R R-W10D4 Sub Box Enclosure with Harmony HA-A800.1 Amplifier & 4GA Amp Kit - 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 SWR-1042D Type-R 10" subwoofer with dual 4-ohm voice coils at Crutchfield
Alpine Type R 12' SWR1243D Subwoofer | eBay
Alpine 12” Type R-Series Powered Ported Bass Package Includes one Alpine R-W12D4 12” subwoofer, R-A75M amplifier, and 2.25 ft³ optimized ported enclosure