high tone during bluetooth usage

[Jammy]

Hi,
For the high tone, is it just the noise during phone call or listening to music when the Bluetooth connected?
The unit may perform different volume level for different function of it and different connected smartphone.
Please adjust the volume level during phone call or listening to music.
Regards

[Jammy]

Hi,
The sound for the other person understanding is not related to the volume level of your side, both the smartphone and the head unit.
Whether the other person can understand you well or not, it's determined by the sound go through the mic and the volume level of its own phone.
And sometime it's also based on the cell phone signal sending and receiving.
Regards

[Jammy]

Hi,
I'm not sure that the tone you said is the incoming call ring tone.
When I tested the incoming call ring tone, the volume at the middle level can be acceptable.
Regards

[Jammy]

Hi,
Sorry for the misunderstood.
For the high tone issue, please restore the factory settings to check, the factory setting restore password is 1234.
If it still does not help, would you mind take a short video,upload it to youtube, then send the link to us?
We will try to provide you positive solution.
Regards