I had the same problem a lot of people have reported here with my X920BT and horrible bluetooth call quality. I could hear the other person fine but to them I sounded garbled and impossible to understand. I was convinced it was not a mic placement issue because a. voice recognition worked fine and b. even if I spoke directly in front of/into the mic I had the same distortion problem.

Anyway, I tried moving the the mic after a few months and now the sound quality is pretty good, huge improvement. So if you are having this issue and have not tried moving the mic yet definitely give it a try.

From where to where?

Mine currently sits between the roof and the front windshield exaclty in the middle of the car(pretty much right above the rear view). I have it rotated to point directly at my head. Occasionally I have issues with the caller not hearing me. I can always hear them. It seems pretty random.

I moved mine to pretty much the same location as yours. Originally it was in the center of the dash, below the head unit (my car has a built in cubby hole/opening there).

From where to where?

 

Mine currently sits between the roof and the front windshield exaclty in the middle of the car(pretty much right above the rear view). I have it rotated to point directly at my head. Occasionally I have issues with the caller not hearing me. I can always hear them. It seems pretty random.

Ah, ok. I was thinking of moving the mic closer to the left side of the car to see if that has any impact.

Mine is at the top of driver side pillar and never had a problem.