So... i did some searching, and this first solution was posted on the german forum for P6
if this bricks your phone, i'm not responsible
using a ROOT BROWSER delete the following folder and all its contents
after doing this, i noticed that sound coming out of headphones is really good "louder" but i also noticed that sound coming out of the speaker is not so crisp, to be honest i never listen to music through the back speaker, it's up to you guys to test it and give some feedback.
Method Two: not tested by me
Using a ROOT BROWSER open this file in your phone with a text editor