Amazon.com: Alpine ALP19-R-W12D2x2wKit Car Audio Type R Dual 2 Ohm 1500 Watt 12" Subwoofers with Sub Install Kit and HA-SWKD Dual Sub Box Install Kit - 16 Screws and Speaker Wire with
ALPINE R-W12D4 12′′ 30cm SUBWOOFER STEREO 4Ω+4Ω MONO 2Ω 750W RMS MAX 2250W SUB | eBay