Amazon.com: CHOOYO 50W 4Ohm 8Ohm Car Subwoofer 4 Inch Woofers Speaker in Car Bass Speaker Long Stroke Loudspeaker for Automotive Sound Box IPC (Color : 1 Piece-8Ohm) : Electronics
Boston Acoustics 8 inch subwoofer driver 8ohm speaker. ***USED*** | eBay
GHXAMP 3 inch Subwoofer Speaker 8ohm 30W Woofer Powerful Bass Long-stroke Large Dynamic 2PCS - AliExpress