Please troubleshoot according to the following methods:
1. Adjust the volume individually by sliding upwards in the touch area;
2. Enable Absolute Volume (or synchronize earbuds and phone volume) in settings and adjust the volume using the volume buttons;
3. In the settings interface of the Xiaomi Earbuds APP, set double press to increase volume, then press the earbuds to adjust the volume;
4. Insufficient battery power in the phone or earbuds is also one of the reasons why the sound is low;
5. Reset the earbuds and pair them again for use;
6. Test with another phone. If the problem persists, please apply for after-sales inspection;
7. Confirm if the earbuds sound outlet is blocked or has foreign objects. If so, please clean promptly.
Note:
It is normal for the sound to decrease in windy conditions or noisy environments like subways.
Does it help?