Sealed / Recessed Sub Box for (2 12") Alpine Type X Subs - Subwoofer Enclosure | eBay
Alpine R2-SB12V Single Type R2 12-in Subwoofer in Vented Enclosure - Creative Audio
Alpine SWX-1243D Type-X 12" subwoofer with dual 4-ohm voice coils at Crutchfield
Amazon.com: Alpine Bundle Compatible with Universal Car X-W12D4 Type X 12" Loaded SPL Bass Subwoofer Labyrinth Vent Sub Box Stereo Enclosure : Electronics
Alpine SWX 1243D Type X 12 subwoofer How to wire the dual voice coils - YouTube