There is some reference to that issue here - https://forum.audiogon.com/discussions/thiel-owners-2?page=87
Best bet is to look for someone local or directions like - https://www.bobvila.com/articles/how-to-fix-cracks-in-concrete/
I owned Thiel 7.2s many moons ago but mine had the mineral composite baffle. Don't know if it true or not but a couple of people told me there were a couple of reasons for the switch. One was about 15 pounds of weight difference per speaker and the other was problems when speakers were shipped overseas (e.g. Asia)
Best bet is to look for someone local or directions like - https://www.bobvila.com/articles/how-to-fix-cracks-in-concrete/
I owned Thiel 7.2s many moons ago but mine had the mineral composite baffle. Don't know if it true or not but a couple of people told me there were a couple of reasons for the switch. One was about 15 pounds of weight difference per speaker and the other was problems when speakers were shipped overseas (e.g. Asia)