A common cause of low Bluetooth volume on Android devices is a system setting called Absolute Volume. Disabling this setting often increases volume substantially.

If you don’t want to wait, there’s an Android app that can bring the same feature to your phone right now. The easy-to-use Bluetooth Volume Control lets you set different default volume levels ...

Android P is expected to soon bring a major improvement to Bluetooth — remembering volume levels for each paired device.

One of these enhancements is in the Bluetooth area – as part of an extension to Bluetooth AVRCP 1.3, Bluetooth audio devices can now directly control Android’s system volume.

"Implement Bluetooth device volume memory" has been approved and merged in the Android Gerrit, so it should roll with one of the upcoming Developer Previews.

Android P adds a lot of neat little tricks and changes to the OS we know and love, and we’ve covered a lot of them here at 9to5. Now, it’s been confirmed that a new feature for Bluetooth audio ...