Sound Issue : No Bass

[EnvyDrums]

Hello everyone, it's my first message here but boy it's been a long time since  I drag this problem... (sorry for my english I'll try my best)

I couldn't tell for how many time the problem occured for the first time, but now at each launches it gets worse.

So I have sound issues with my PC, I don't know what causes this (i suspect B&O Audio for this but i'm not sure).

The problem can occur differently, but it always happen when I start PC, never in a middle of use.

- I start my PC, first thing is play a sound (youtube or media player) and the sound is flat, no bass. 30sec to 1min generally, the bass automatically pops up and i have nice sound for the rest of my use. So thats why i didn't bother writing here as it sort itself generally in a couple of seconds.

But apparently today it refuses to "switch", ho and of course sometimes I have good sound immediatly, it's not a 100% issue, often but not each time.

- I tried to do as KrazyToad said in here : https://h30434.www3.hp.com/t5/Notebook-Audio/Sounds-sounds-flat-with-headphones-No-Bass/td-p/6524000

AND IT WORKED ! (For approximately 5 seconds) Uninstalling Realtek Driver, windows automatically reinstalled it and the sound was good, and "something" happened in background and switched to flat sound I don't understand.

I tried to update Realtek, didn't work, tried to uninstall B&O, didn't find how to do. I'm a little lost with this. And besides the fact that flat sound is annoying as hell, my job is musician/music teacher and this pc is for work so... i'd like to have a nice sound.

Thanks for whoever try to help me, i'll provide any info you'll ask. Have a good day.