Amazon.com: Audiopipe 6" Woofer 150W Max 4 Ohm DVC Sold Each : Electronics
Amazon.com: American Bass HAWK 15 Inch Dual 4 Ohm Voice Coil 3000 Watt Subwoofer Speaker with 80 Ounce Magnet and Kevlar Fiber Non-Pressed Paper Cone, Red : Electronics
Amazon.com: Black Diamond Car Audio 15" Bass Subwoofer 4-Ohm Dvc 600 Watts DIA-15D4 : Electronics
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
Amazon.com: Skar Audio SDR-15 D4 15" 1200 Watt Max Power Dual 4 Ohm Car Subwoofer : Electronics
Amazon.com: Gravity Audio 1200W Professional 12" Power Car Subwoofer 4 OHM IMPED Dual Voice Coil GR-12PW : Electronics
Amazon.com: Facmogu 2PCS 8in Full Range Audio Speakers, RMS 50W Peak 120W, 4 Ohm Car Vehicle Audio Full Range Drivers, Wide Range DIY Loudspeaker Woofer Replacement - Red : Everything Else