Amazon.com: Skar Audio EVL-18 D4 18" 2500 Watt Max Power Dual 4 Ohm Car Subwoofer : Electronics
DB Technologies 1030102570 Subwoofer Boxes Active : Amazon.de: Musical Instruments & DJ
ESX VX21PRO - 21 Inch 53 cm Extreme SPL Subwoofer : Amazon.de: Electronics & Photo
Amazon.com: Pyle 6.5 Inch Mid Bass Woofer Sound Speaker System - Pro Loud Range Audio 300 Watt Peak Power w/ 4 Ohm Impedance and 60-20KHz Frequency Response for Car Component Stereo PLG64 : Electronics
Amazon.com: Lanzar 6.5” Car Subwoofer Speaker - Black Non-Pressed Paper Cone, Aluminum Voice Coil, 4 Ohm Impedance, 600 Watt Power and Foam Edge Suspension for Vehicle Audio Stereo Sound System - MAXP64 : Electronics
Amazon.com: DS18 SLC10S Car Subwoofer Audio Speaker - 10" in. Paper Glass Fiber Cone, Black Steel Basket, Single Voice Coil 4 Ohm Impedance, 440W MAX Power and Foam Surround for Vehicle Stereo