I'm really stumped by the issue that i'm having with a Sony Xperia S.
The phone has been working perfectly with the car head unit, which is a Becker Cascade 7944, although it didn't do A2DP music streaming (which I don't think the head unit supports) the handsfree call quality was perfect.
Anyway, the other day it stopped working properly. Incoming and outgoing calls are completely inaudible. It's completely distorted, difficult to explain I know, but it's the fact that the phone and head unit used to work perfectly together, and nothing has changed yet this problems started.
Things i've tried so far: unpairing the phone from the head unit (and also removing the head unit from the phones bluetooth list). And also a complete reset of the phone with Sony PC companion.
Despite doing the above, the problem is still exactly the same. I have tried the Xperia S with another cars bluetooth system and it's perfect again. I have also tried an Xperia Z1 in the original car and that works fine too.
So i've come to the conclusion so far that the head unit is fine, and the Xperia S is fine... I just can't figure out whats wrong.
Can anyone help?