Why can no one understand when making calls on car stereo

[Android Central Question]

I have a kenwood dmx 7107dabs radio and a Samsung galaxy s9+ phone I can receive calls fine through stereo but the other end can't make out what I am saying,it worked fine on factory fitted vauxhall head unit

 

[Rukbat]

The mic in the Kenwood might be blocked by something, or it may be bad. (I have mine dressed through the dash, the quarter pillar and out to the sun visor, so it's near my mouth.)

 

[trucker3573]

Yeah sounds like a stereo problem. If you want hands free...hands down without contest blue parrot headsets win the battle. Check them out you will never use an in car system again and people on the other side of the call will love talking to you.