I'm not sure I'd send the good one though. They won't warranty a good speaker. If there's a factory defect of some kind, you bet they will. But they won't send a matched pair or anything like that. New devices are expected to meet specs, and they are examined by QC but that's the extent of it.

That does bring up an interesting issue though. Just like some people buy tubes in bulk and then test them to provide matched pairs, this could be done with loudspeakers also. Probably best to do it on the expensive devices, since the service would add considerable cost. But it is an interesting idea.