How to Increase the Headset Volume of the Huawei P9 Lite with Root
The European Union puts limits on how loud the headset music volume can be on smartphones released within its member nations. While a noble attempt at keeping people safe, some feel it takes things too far and ruins their music-listening experience. So, if you have root access on your Huawei P9 Lite then you can follow this guide laid out below by XDA Senior Member XeLLaR* to increase the volume level. This method has been tested on firmware versions B370/B380 of the Huawei P9 Lite.
Check out this guide in our Huawei P9 Lite forum