at 1st let me state that this is not my work, it's the work of @Dante63 that's posted and maintain by him on the Miscellaneous Android Development Section of XDA... i just helped him test it.
this works on OnePlus 3 & 3T.
Update Sept 2nd 2018
based on 5.0.5 file was provided by @mcdachpappe big thanks to him
Updated to Magisk Template 17.0
Download from Google Drive
Version 1.0 (outdated and wont work on newer OOS 5.0.X)
on the GDrive forlder there're 4 files
1- the original file used to make the mod (may be used to revert for non Magisk users without backup)
2- DYI file for manual placement with root explorer (system/vendor/etc with 0644 permission)
3- TWRP flashable zip
4- Magisk Module
Note & Warning /
when using this mod with AML (Audio Modification Library) you need to either install it after AML or replace the file "mixer_paths_tasha.xml" inside the AML module with the one in this mod, other wise the file included on AML will be the one working and this mod wont.
DIY Volume Level:
Speaker Volume isn't present in the mixers
<path name="speaker"> ------------------ <ctl name="RX0 Digital Volume" value="90" /> <!--earpiece , default is 84, Safe up-to 95, beyond is DANGEROUS--> ------------------ </path>
again All thanks to @Dante63 to his work and support.
to check change logs