Alpine SWR-12D2 Type-R 12" subwoofer with dual 2-ohm voice coils at Crutchfield
Amazon.com: Alpine ALP19-R-W12D4 Car Audio Type R Series Sub Dual 4 Ohm 1500W Peak 12" Subwoofer : Electronics
Alpine SWR-1242D Type-R 12" subwoofer with dual 4-ohm voice coils at Crutchfield
Alpine SWR-1042D Type-R 10" subwoofer with dual 4-ohm voice coils at Crutchfield
Amazon.com: Alpine ALP19-R-W12D4 Car Audio Type R Series Sub Dual 4 Ohm 1500W Peak 12" Subwoofer : Electronics
Alpine Type R 12" Unboxing And Demo | R-W12D4 - YouTube
FS: Alpine Type R 12" sub + JBL BP300.2 mono amp - BMW 1 Series Coupe Forum / 1 Series Convertible Forum (1M / tii / 135i / 128i / Coupe / Cabrio / Hatchback) (BMW E82 E88 128i 130i 135i)
LAB SlapBox™ 2.25 ft^3 Ported MDF Enclosure Box for Single Alpine 12" R-
Single alpine type r 12" ripping car apart - YouTube
Alpine Halo R2-Series Dual 12" Voice Coil 4-Ohm Loaded Subwoofer Enclosure Black R2-SB12V - Best Buy
Alpine S-Series 12" Dual-Voice-Coil 4-ohm Subwoofer Black S-W12D4 - Best Buy
Alpine Type R 15 Box Design - ecoustics.com
Alpine 12" Type R - which sealed box | AVS Forum
Alpine Type R 12 Dual Ported box | Car Audio Forum - CarAudio.com