Alpine SWR-1242D Type-R 12" subwoofer with dual 4-ohm voice coils at Crutchfield
Alpine 10 Inch Type-R Subwoofer (R-W10D4/D2) | SK Customs Car Audio & Home Theater | Atlanta | Norcross | Duluth | John's Creek
Amazon.com: Alpine R-W10D2 Car Audio Type R Series Sub Dual 2 Ohm 2250W Peak 10" Subwoofer and HA-SWKD Dual Subwoofer Sub Box Install Kit : Electronics