Q: Will this work on other Samsung devices?
A: Maybe, I see no reason for it not to work on the S8 or S8+. Feel free to test it out and report back.
Credits: @zhuhang for ViPER4Android FX & XHiFI.
@partcyborg, @me2151, and @elliwigy for hooking us up with root.
Features: Systemwide ViPER4Android FX 22.214.171.124 (higher audio processing than newer versions) and ViPER4Android XHiFi.
Installation steps (make sure to read these before downloading the ZIP):
1) Make sure you're rooted.
2) Download either FlashFire (Snapdragon - thank you, @Chainfire) or install TWRP (Exynos).
3) Install BusyBox, to /system/xbin (otherwise, XHiFi will not work, only FX will).
4) Get Titanium Backup, ROM Toolbox PRO, or any similar application.
6) Freeze "Adapt Sound" and "SoundAlive".
5) Flash the attached zip.
6) Grant root permissions to both FX and XHiFi (you might have to uninstall the FX driver within the in-app settings to trigger this, if so, simply reflash the ZIP after having done so and reboot).
7) Reread step six.
8) Profit & enjoy.