Amazon.com: 10" Car Audio Speaker Subwoofer - 1000 Watt High Power Bass Surround Sound Stereo Subwoofer Speaker System - Non Press Paper Cone, 90 dB, 4 Ohm, 50 oz Magnet, 2 Inch
Alpine W10S4 10" 750 Watt Peak 250 Watt RMS 4-Ohm Car Audio Subwoofer Sub - Walmart.com
Ghxamp Hifi 4 Inch Subwoofer Bass Speaker Carbon Fiber Cone Woofer Speaker 4ohm 40w Low Frequency For Home Car Audio Unit 1pc - Speakers - AliExpress
Amazon.com: Alpine SWA-12S4 BassLine Series 12" 4-ohm Subwoofer : Electronics