I've moved this guide to a post in the general section, I recommend going there as it will be updated if anything is found: http://forum.xda-developers.com/nexu...droid-t3250579

OK everyone, there seems to be mass confusion on what to do to get Viper4Android running.DO NOT USE THESE FILES UNLESS YOU HAVE A NEXUS 6P. SO MANY PEOPLE HAVE ISSUES BECAUSE THEY USE FILES DESIGNED FOR OTHER PHONES.Firstly: Are you running normal root or systemless root?If you are running systemless root, then you will never get Viper4Android running without it being modified so it isn't hardcoded to su. Also it modifies the system partition so you won't be able to use Android Pay anyway.Secondly: Have you flashed any of the billion V4A recovery zips?If yes, restore your system partition as those have a billion and one differently modified files that will probably screw over how your phone functions.OK, now it is time to continue.Choose your favorite v2.3.4.0 version of V4A and install it to /system/priv-app/. Just create a folder with the same name as the APK, give it the same permissions as the other folders, and drop the APK in it making sure to also give it the permissions that the other APKs get.If the files linked below can't be downloaded, use the zip file at the bottom of this post and continue following the guide.Now, download this file (49_viper4android.sh) : https://www.dropbox.com/s/rcp77ul41m...ndroid.sh?dl=0 And create a folder called su.d in /system/. The path should be /system/su.d/, and then give it permissions 0700 with root:root, and drop the script into the folder with permission 0755 with root:root. This script will allow V4A access to mediaserver, so it can see audio to do it's magic. You can make sure that the script worked on boot by checking /data/v4a_script.txt for if it exists, or, was modified recently to correlate with you booting your phone.Now do the same for this file (audio_effects.conf) : https://www.dropbox.com/s/57y44o74dk...ects.conf?dl=0 And drop the file in /system/etc/ AND in /system/vendor/etc/. Both of the files should have permissions 0644 with root being the owner and group. This modified file will allow V4A to be used as an equalizer and allow it to do magic in your audio.Now lastly, the last file which will allow V4A to work system-wide, like in YouTube (audio_policy.conf) : https://www.dropbox.com/s/yi8u3j91z3...licy.conf?dl=0 And drop it in /system/etc/ and give it permissions 0644 with root being owner and group, and you are good to go. This modified file removes the "deep_buffer" module that made it so apps that don't hook into Viper4Android (apps that aren't music players) wouldn't have their audio processed. Some of the flashable zips included modified files, but usually only for the Nexus 5.After that just continue with the Viper4Android installation and you will be good to go.