Amazon.com: 2X Gravity 8 Inch 1000 Watt Car Audio Subwoofer w/ 4 Ohm DVC Power 8' Sub Pair - Feature Dual Voice Coil, Thick Magnet, Design for Car, ATV, Van, High Performance
Amazon.com: Car Two Way Speaker System - Pro 6.5 Inch 240 Watt 4 Ohm Mid Tweeter Component Audio Sound Speakers For Car Stereo w/ 30 Oz Magnet Structure, 2.25” Mount Depth Fits
Amazon.com: 2X SoundXtreme Premium Elite ST-410 10 Inch Car Audio Subwoofer 3000 Watts Max Power Dual 4 Ohm Voice Coil High Power Bass Surround Sound 10" Sub Speaker System : Electronics