Does BlueTooth transmission go thru walls/doors?

I believe that that is a best-case scenario, i.e. with no obstructions or interference.

For what it's worth, though, I am able to get crackly reception through a 15cm concrete wall from about five metres away. Not really useable, but it does work.

For us Yanks, what Ben S. meant to say was:

"I believe that that is a best-case scenario, i.e. with no obstructions or interference.

For what it's worth, though, I am able to get crackly reception through a 6in. concrete wall from about sixteen 1/2 feet away. Not really useable, but it does work."

😉

Thanks for the conversion, Michael. And apologies for ignoring those who are more familiar with the imperial measures.