two woofers/speaker, you will need a single matching driver
OR, replace all 4 woofers
Patience, keep an eye out on hifishark till one shows up
https://www.hifishark.com/search?q=ads+l710
or/meanwhile, investigate the speaker's specs and what 4 replacement woofers will work and cost.
partsexpress, or madisound have good advice
https://www.madisoundspeakerstore.com/welcome