Kenwood Excelon P-XW1221D Ported 2-ohm enclosure with two 12" subwoofers at Crutchfield
Amazon.com: Boss Audio Systems P126DVC Phantom 12-Inch 2300 Watts 4 Ohm Dual Copper Voice Coal Car Audio Stereo Subwoofer Speaker with Poly Injection Cone : Electronics
Sony XS-GSW121D 12" Subwoofer Driver - Dual 4 Ohm
Jensen J12W 12-inch 1200 Watts Peak Power Polypropylene Subwoofer with Reinforced Stamped Steel Basket and 40oz Magnet - Walmart.com
Amazon.com: DS18 SLC12S Car Subwoofer Audio Speaker - 12" in. Paper Glass Fiber Cone, Black Steel Basket, Single Voice Coil 4 Ohm Impedance, 500W MAX Power and Foam Surround for Vehicle Stereo
Boss Audio Systems P126dvc Phantom 12-inch 2300 Watts 4 Ohm Dual Copper Voice Coal Car Audio Stereo Subwoofer Speaker With Poly Injection Cone : Target
Amazon.com: Pyle 12' Car Audio Speaker Subwoofer - 1600 Watt High Power Bass Surround Sound Stereo Subwoofer Speaker System - Non Press Paper Cone, 90 dB, 40 Ohm, 60 oz Magnet, 2
Boss Audio Systems 12 in. 1000 Watt Subwoofer - Speaker