It makes your headphones(3 levels) , bluetooth(1 level) and speaker(1 level) louder. Simply Open an explorer I use es file Explorer and go to device and remove the mixer paths xml file and replace it with mine.Make sure you fix permissions before you reboot or you may go to a bootloop.The file is located on device at system folder then etc folder then find the file mixer paths file and move or replace it then put my file in it's place.Then fix permissions on the file or just flash zip in Twrp and reboot.
Here is file: https://www.dropbox.com/s/2ocsij0cmz...paths.xml?dl=0
Here is v1 flashable zip : https://www.dropbox.com/s/1kmm32mrsw...moVol.zip?dl=0
Here is v2 flashable zip : https://www.dropbox.com/s/zjo5anrx11...udMod.zip?dl=0
Here is the mixer paths file if you prefer
Here is v3 flashable zip : https://www.dropbox.com/s/68cd8iaplm...Sound.zip?dl=0
Here is mixer paths for v3 : https://www.dropbox.com/s/msym0i1cfb...paths.xml?dl=0
7 levels higher on headphones and bluetooth higher also speaker and ringtones 3 levels higher
Here is V6 Final Zip:https://www.dropbox.com/s/8ppkwuwshn...Sound.zip?dl=0
Speaker optimized and headphones louder everything else the same as V5 Enjoy and here is the mixer path file if you rather push:https://www.dropbox.com/s/waxf4rmvka...paths.xml?dl=0
Here is stock one in case you messed it up https://www.dropbox.com/s/5rgory0ppb...paths.xml?dl=0
Tested only on the T'Mobile Galaxy S6 Edge variant don't know if it will work on others.
Instructions for viper4android