Got my MBP back from Apple, but my speakers seem off

So, since my battery expanded, I took my 2015 15" MBP Retina to Apple for the battery and top case replacement. My speakers were replaced not too long ago, and should still be under warranty. They sounded really rough when I tested everything before I took it in, and the Genius told me that if they had been damaged, their repair would be included.

So I got it back a couple of days ago and I’ve been using it off and on since then and… something just isn’t quite right. The start up chime (bong) is DEFINITELY different (and uglier), but when I listen to even rather complicated music, I can only just tell that something is off, but I can’t really put my finger on it. It’s just… not the same sound profile, if that makes any sense?

It’s nothing like when the speakers went before, they got all scratchy and tinny. That’s not this… This is like… not completely full. Just a bit dampened. I’m not even sure anyone else would be able to tell what I mean.

Any ideas what might have happened? Do I go back to Apple? Is it all in my in mind? Was there some kind of firmware update? Maybe it’s the most recent Catalina supplemental update? It’s nagging at me.