Alpine Type-R SWR-1542D 2000W Peak 15" Type-R Series Dual 4-Ohm Sub
Alpine SWR-1522D Type-R 15" subwoofer with dual 2-ohm voice coils at Crutchfield
Amazon.com: Alpine Bundle Compatible with Universal Vehicles S-W12D4 Single 12" Loaded Sub Box Enclosure : Electronics
2) ALPINE SWR-1542D 4000W 15" CAR AUDIO SUBWOOFERS TYPE R WITH 4-OHM DVC SUBS | eBay
Best Buy: Alpine Type-S 15" Dual-Voice-Coil 4-Ohm Subwoofer Black SWS-15D2
Alpine BBX-T600 Amplifier and CWCS154 CompC 15" Subwoofer Single Voice Coil 4-Ohm - Includes wire kit - Creative Audio
Amazon.com: Universal Car Stereo Vented Port Single 12" Alpine S-W12D4 Type S Car Audio Subwoofer Custom Sub Box Enclosure Package New Without Amp : Electronics
Alpine R2-W10D4 at Onlinecarstereo.com
LAB SlapBox™ 3.50 ft^3 Ported MDF Enclosure Box for Single Alpine 15" Type-R Subwoofer
2) Alpine SWS-15D2 15" 3000 Watt Car Subwoofers + Vented Sub Enclosure Box | Audio Savings