How to lower minimum iPhone / iOS volume listening to streaming app on bluetooth headset
the " Audio Volume Balance slider " is only a setting to either reconfigure the ear piece so that if one ear piece is more louder than the other. You can change it through that setting or to check if you think one piece is not working this will allow you to verify this, but it is NOT to lower the volume on ear pieces for that you need to press the volume buttons on your iphone or the bluetooth headsets themselves or find the " Audio slider " in the " Audio streaming apps " themselves.   To " lower the minimum volume " is based on personal preference. If changing the volume this way does not work then you may be facing a product quality issue in bluetooth headset because not all bluetooth headsets are created equally