4 Inch High-End Shielded Woofer: perfect for replacing/upgrading or building bookshelf, surround, sound bar speakers, or other diy speaker projects.
Amazon.com: JINGERL 50W 4Ohm 8Ohm Car Subwoofer 4 Inch Woofers Speaker in Car Bass Speaker Long Stroke Loudspeaker for Automotive Sound Box IPC (Color : 1 pieces-4Ohm) : Electronics
Source Super Woofer 4.5 Inch Subwoofer Speaker For Home Audio on m.alibaba.com
METIS-18SDPW 18" 2400W PA DJ powered subwoofer for stage, church, bar, restaurant – Sound Town
Crunch Crw12d4 12 Inch 800 Watt Rms 4 Ohm Dual Voice Coil Car Audio Subwoofer Speakers With Spade Terminals For Sealed Or Vented Enclosure (2 Pack) : Target
Faital PRO 12RS1066 12 Inch Long Excursion Neo Subwoofer 4inch VC 2000 – SpeakerAddict
AudioPipe TXX-BDC4-12 Dual 4 Ohm 12 inch 2,200 W Car Subwoofer, Black (2 Pack) - Walmart.com
GHXAMP 1PC 4 inch 40W Subwoofer Speaker Woofer High Power Long Stroke BASS Home Theater For 2.1 Subwoofer unit Loudspeakers DIY - Price history & Review | AliExpress Seller - GHXAMP Worldwide Store | Alitools.io
4 Inch 105mm Speaker Subwoofer Speaker Bass High Power 4ohm 40w Long Stroke Computer Car Home Theater Loudspeaker 2pcs - Speakers - AliExpress