[P8lite Q&A, Help & Troubleshooting] wolfensg:
[ I've decided to rewrite the original description to make it more like a guide (since already I've found few interesting things :) ]

P8 Lite is quite ok in terms of hardware to make it nice music player. However comparing to old and rusty Samsung Galaxy Ace2 its sound quality is worse.

According to the tests (and hours of tests/comparisons I performed with two different high quality headphones) P8 Lite is only slightly worse but its main issues are significant stereo crosstalk and strangely boosted parts of middle tones.

http://www.gsmarena.com/huawei_p8lite-review-1280p7.php

http://www.gsmarena.com/samsung_galaxy_ace_2-review-786p5.php

While EMUI 4.0 update introduces DTS which can be enabled and helps in terms of crosstalk it does very strange thing - boosts bass and treble but decreases some middle tones thus some tracks appear to sound kind of awkward and unacceptable.

Another thing is I wanted to also benefit from the HUAWEI lockscreen (I have linked my phone with corporate account which enforced me to have the pin lock on the huawei lockscreen and because of this - having additional lockscreen was not an option for me).

Other things to be considered while trying to find a good player were: folder play (I have my stuff well organized), nice widgets, good audio quality, ui that won't make me wanna throw the phone out of the window while using it ;)

To keep the description clean I would mention only players which are significantly better and other tweaks I've used to make the audio quality better (actually - given the hardware limitations of P8 Lite - to be as close to Ace2 as possible).

Test base:

P8Lite with Marshmallow 6.0 Stock EMUI 4.0 B564

Players which performed very well in terms of quality without any hacks/flashes/blackmagic :P

- MyPlayer++ (lots of configuration options in terms of audio quality, nice widgets, no huawei lockscreen support) http://xdaforums.com/android/apps-games/app-myplayer-lightweight-music-player-t2892233

- DroidSound-E (only if DTS was enabled, may also be true for other music players based on BASS library, awful widget (need thirdparty widget like PlugInMusic Player), no huawei lockscren support) https://github.com/droidmjt/Droidsound

- PowerAMP beta (as suggested by [MENTION=6258829]Zero_Rik[/MENTION]) (audio quality and configuration capabilities comparable to MyPlayer++, nice widgets (configurable), HUAWEI LOCKSCREEN SUPPORT (hurray!) http://forum.powerampapp.com/index.php?/forum/18-poweramp-v3-testing/

Players which I don't like but do have huawei lockscreen support:

- Huawei Music Player (you didn't expect this one? :P)

- Google Play Music

After playing around with various players still I was unhappy with the sound quality (although PowerAMP at least apart from good overal quality introduced the lockscreen support). Also I wanted the sound to be similar across all applications therefore I did not want to use PowerAMPs equalizer.

Solution #1 - Dolby Atmos ( http://xdaforums.com/p8lite/themes-apps/dolby-dolby-atmos-t3305789 )

Instalation was simple (flashing two packages in a row) but required recovery to be exchanged from stock to TWRP.

Once installed Dolby Atmos was working more or less fine but did not work in any way possible with PowerAMP.

Uninstallation is possible by flashing third package. Worked nice though for DroidSound-E

Solution #2 - DSP Manager from CyanogenMod ( http://xdaforums.com/google-nexus-5/themes-apps/equalizer-dsp-manager-lollipop-versions-t3106546 )

Installation was simple (again two packages). No straightforward uninstall (so I've made OS backup in TWRP).

This time audio quality was really really (tested in DroidSound-E and PowerAMP)

Solution #3 - Viper4Droid (did not test this one but people say its good :)

Please note that flashing another recovery over existing (installing TWRP) will prevent you from updating system to any further updates (unless you reflash your original stock recovery partition).

Also worth noting that custom DSP (Atmos or DSP Manager from CM or Viper4Droid) may not work for some music players!