JBL ASB6112 4000W 12-inch Passive Subwoofer - White | Sweetwater
Amazon.com: Rockville W12K9D2 V3 12" K9 V3 4000w Peak/1000w RMS Car Subwoofer DVC 2-Ohm Sub : Electronics
Bass Rockers - 12 Inch Loud Competition Subwoofer - 4000W/ 2000W RMS - Max Program Power - Car Audio for Pro Car Stereo - Woofers Home Theater (4-ohms) - BRNK12v2 - Walmart.com
ATG Audio Transcend Series 15" DVC 4ohm Woofer
DAS VANTEC-218A 2x18" Active Subwoofer, 4000W | Full Compass Systems
18 Sound 18NTLW5000 18" High Performance Neodymium Subwoofer 4000W Program Power | Reverb
American Bass 12" HD Series Subwoofer 4000W Max Dual 1 Ohm HD-12-D1v2 | eBay