2) Alpine Type-R R2-W12D4 12" 750w RMS Car Subwoofers+Vented Sub Box Enclosure - Rockville Audio
Building a Ported Box for a 12" Alpine Type R - YouTube
Amazon.com: Alpine R-W12D4 Car Audio Type R Series Sub Dual 4 Ohm 2250W Peak 12" Subwoofer and HA-SWKD Dual Subwoofer Sub Box Install Kit : Electronics
Sealed / Recessed Sub Box for (2 12") Alpine Type R Subs - Subwoofer Enclosure | eBay
Alpine 8" Type R Single Enclosure | P.C. Richard & Son
Universal Car Stereo Vented Enclosure Single 12" Alpine R2-W12D4 Type – absoluteusa
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