First make sure your RX570 is recognized in Device Manager under "Display Adapter".
If it is, then download the latest AMD Driver for your GPU card from here: https://www.amd.com/en/support/graphics/radeon-500-series/radeon-rx-500-series/radeon-rx-570
If it still doesn't show AMD HD Audio in Device Manager then try installing a previous AMD Driver from here: https://www.amd.com/en/support/previous-drivers/graphics/radeon-500-series/radeon-rx-500-series/rade...
It is possible that Nahimic is preventing AMD HD Audio from working or is in conflict. Can you temporarily disable or uninstall Nahimic Mirroring device and also your Creative Stage Air soundbar and then try to install the AMD Driver again and see if it shows up in Sound Panel and Device Manager.
Then use this method to install and remove your AMD Driver from your computer:
Uninstall the current AMD Driver using DDU as per this method:
It could be due to a corrupted AMD Driver installation.
Download free program DDU (Display Driver Uninstaller). Run it in Safe mode with the internet disconnected.
You can also run it in Windows Desktop but then you would need to Reboot the computer for DDU to finish erasing all of the AMD Driver traces from your computer.
Once it finishes uninstalling the current AMD Driver in Safe mode and boots back to Windows Desktop, still with the Internet disconnected, delete the AMD Installation folder C:\AMD if it was created before.
Now install the full AMD Drive package you downloaded manually from AMD Download page. Not the express package. Run the package and if it installs correctly again delete C:\AMD folder and reconnect the internet.
This should prevent any conflict when installing the new version from the previous version.
By the way, C:\AMD is always created whenever you run the AMD Driver package
If AMD HD Audio is showing in Device Manager and Sound Panel, you can now enable Nahimic and Creative Stage Air sound bar and see what happens.
NOTE: You must choose and click on "Audio Default Device" in Sound panel to make Audio work on your computer. If you click on Nahimic or Creative Stage Air Sound bar and it isn't using the AMD HD Audio driver then that will be your Default Audio Device for your computer.
