Alpine SWS-1243D 12" Inch 30cm 900 WATTS Dual Voice DVC Car Sub Bass SubwooferAlpine SWS 1243D 12" Inch 30cm 900 WATTS Dual Voice DVC Car Sub Bass Subwoofer Alpine builds the speaker leads into the spider, so they can't shake loose during extreme cone movement. A network of cooling vents reduces heat induced distortion, so you can push your music and leave the meltdown worries behind. The dual 4 ohm voice coils give you more options for tweaking your bass, whether you're looking to wire up a multi sub system or draw more power