Amazon.com: Visaton Full-Range Speaker 10 cm (4'') 8 Ohm 30W 100-V System : Electronics
Gladen GA-100Z-3 10cm woofer speakers
2pcs 4inch Car Auto Speaker 10cm 150w Dual Cone Car Coaxial Speaker Horn Audio Sound Box Loudspeaker Full Range Speakers For Car - Speakers - AliExpress