I'm sure most people here have noticed that the audio in the earphones is very low and doesn't deliver very good sound, but I have found a easy fix for this which takes like 5 minutes to apply.
- Viper4Android FX
2. Now open the Viper4Android app again and select "Headset" at the top, then check the box for enable under Master Power. After you have done that, check the enable box for Playback Gain Control, and in "Select effect strength" chose Extreme.
Enjoy! The sound should be alot higher now and the bass should also have been improved by this quick fix.