Its my first post :)
I find this solution on other polish forum.
How to run HiFi audio on spotify or another music apps :)
- First we need root on phone and any root browser.
- Open root browser and go to system -> etc -> audio_hifi.conf
- You see all applications that use audio HiFi
you just need to add the name of application on the end of list
its look like: package com.spotify.music, “package” always must be first.
- You can check name of application for mx4pro in data -> app for pro 5 data -> data
- write file and check permissions it must be 0644 rw–r--r
- restart phone and you have HiFi mode enabled for other app than flyme music player :D
Sorry for my english