TLDR: Use Equalizer APO + HeSuVi plugin. Retask your jacks to Stereo Mix.
Yeah, this and many other motherboards that come with DTS which is supposedly a premium feature don't have any of the Sound Effects or Equalizer in the Realtek Audio Console app. They send us to the DTS Unbound app which is useless if you have analog connections (3.5mm jacks).
Uninstall everything you have first. The best solution I found is to install the drivers from AAFOptimus: https://github.com/AAFOptimus/AAFFamilyDCHAudio/releases choosing the classic "Realtek HD Audio Manager (Legacy)" or "Realtek Audio Console (Universal)" with "Only Realtek Effects Suite". There you'll have all the options you want, such as Speaker Fill, Room Correction, Equalizer and crazy effects like Arena, Auditorium, Concert Hall etc.
HOWEVER, this Speaker Fill option is bad. This is a Windows or Realtek problem since forever. The sound on the rear speakers will be low and distorted and there's very little bass. I've struggled years to find the best solution ever since 2016. And while I found an official driver for my old Intel 6th gen mobo where I could just re-pin or retask the jacks in the registry, that has stopped working on newer versions and subsequently on any newer motherboards.
The jack retasking looked like this:
"Pin14"=hex:04,00,00,00
"Pin15"=hex:04,00,00,00
"Pin16"=hex:04,00,00,00
Basically setting Pin15 and Pin16, the Central/Sub and Rear outputs the same as as Pin14 (the Front). And so any Stereo source would play on all Speakers. And if I really wanted to experience a movie in true Surround, I would undo this retasking. It was that simple.
But with my new B850 motherboard, obviously that driver doesn't work anymore. So after spending months and long nights on researching, even considering buying dedicated sound cards, which they come with good Virtualization options, I realized they're still not perfect, not even Dolby Atmos. All these things are either made for Headphones or digital outputs through HDMI.
Then, I found the Holy Grail: Equalizer APO + HeSuVi plugin. I've used Equalizer APO in the past but I didn't know about HeSuVi. What this does is the same jack retasking I was doing with my old mobo. AND, you can even use Virtualization effects if you want as well.
The best part is that neither Equalizer APO nor HeSuVi will stay open in the background. There's no process running as far as I know. You set it once and forget about it. And it occupies 71 MB.
Once you install these 2, make sure you've set up 5.1 configuration in your driver (either from windows settings or Realtek software), then select your desired output on EqualizerAPO, then open HeSuVi and go to the Connection tab, enable the Orange and Black jacks if they aren't, then select Stereo Mix on all 3. That will upmix your stereo sources to 5.1. Whenever u wanna go back to true 5.1, just select Raw Front, Raw Ctr/Sbw and Raw Rear. You can play with the Virtualization option too. Select that on each jack then go to the Virtualization tab and choose what u wish.
A small update:
The latest AAFOptimus/AAFFamilyDCHAudio drivers have got some issues with the Amplify Level setting in the classic Realtek HD Audio Panel. For me, at least.
And what I found out is that on versions from 9862.1 and older (with Effects + Patched APO where's the case), all the Sound Effects appear in the new UWP Realtek Audio Console, so go with 9862.1 version for this particular motherboard.
Edit: New version 9882 have the sound effects when you choose "Install only Realtek Effects Suite".
The Speaker Fill / Virtualization story remains the same. Use Equalizer APO + HeSuVi as I've said above.
