I have a Doogee X30 on Android 7.0. Even on the lowest media volume (slider on first non-silent stop), the output is way too loud. I am trying to lower the value of a media slider's starting point (ideally, decrease the volume of at least the first half of the volume levels of the slider).
In engineering mode, I tried changing values to lower, but it doesn't seem to be doing anything. After every change, I clicked the set button. I have even tried restarting the phone, but the result is the same. Even on the lowest slider value, the volume is very loud (like at 3/4 of my previous phone's maximal volume). I was changing values in Hardware Testing -> Audio -> Normal mode -> Type = Media.
Am I even changing the right values? Because even if I set some level to 0, or even maximal volume to 0, sound volume doesn't change at all.
P.S. It's a newly purchased phone (week old), nothing custom like ROM, root, Xposed, or anything like that (don't even know what Xposed is). I have installed a bunch of apps, but I don't think that they can change such settings in vanilla Android.