Oh goodness, this was the only thread that helped me solve my volume variability. Thanks for the input, everyone! I usually listen to music while working and the changes in volume was starting to affect my productivity.
I have an HP Elitebook 840 for work and was a bit heartbroken when I couldn't find "SRS Premium Sound PRO" in my Control Panel. BUT WAIT, there's "DTS Audio Control Panel"!
I clicked on "Listening Experience" and then UNCHECKED THAT SUCKER.
All good now! 🙂