Amazon.com: Pyle Car Subwoofer Audio Speaker - 8in Non-Pressed Paper Cone, Black Plastic Basket, Dual Voice Coil 4 Ohm Impedance, 800 Watt Power and Foam Surround for Vehicle Stereo Sound System -
Amazon.com: Lanzar 8 inch Car Subwoofer Speaker - Black Non-Pressed Paper Cone, Aluminum Voice Coil, 4 Ohm Impedance, 800 Watt Power and Foam Edge Suspension for Vehicle Audio Stereo Sound System - MAXP84 : Electronics
60-150w 8 Inch Bass Speaker 8 Inch Subwoofer Speaker 8 Inch Speaker Cinema Subwoofer Car Subwoofer High Power Long Stroke - Speaker Accessories - AliExpress
Sony XS-GS80L GS Series 8" 4-ohm subwoofer at Crutchfield