Thanks for your kind reply . . . you wrote . . .
Your sound quality “now”? It was okay previously?
Yes, it was as good as all my other computers (I sit in a “U” shape configuration . . . a 27" screen for my Mac Sierra computer to my left, a 21" screen to my old XP computer [where I’ve done all my Cubase SX recording] at center, and my 27" Windows 10 computer to my right).
Sound quality is equally “TERRIBLE” whether from Cubase or other software?
Yes . . . no matter what I play from the affected computer (Itunes or whatever) it all sounds the same.
Make sure you don’t have anything funky enabled within the Realtek control panel as far as effects and whatnot go.
Hmmm, I don’t know—as yet—how to get to any Realtek Control Panel. At least I haven’t found it yet.
Cubase will let you use the onboard Realtek sound device, but unless it has it’s own dedicated ASIO driver (I’m 99.9% positive it doesn’t) you will need to select a driver such as (the mysteriously installed) ASIO4ALL.
I’ve tried to switch to that . . . but I will try that again. Thank you so much for your time.