Iphone XS earpiece sound when calling people not as clear as Iphone 6s? help

I just got an iPhone XS, came from a 6s, and I can't instantly tell a difference from the earpiece and call quality sound. it's not as crispy and sounds like more slightly muffled, like the treble is tuned down like on a radio. i cannot get used to the sound quality when making voice calls.

I have upgraded from an iPhone 6S, and have noticed that the sound is very weird (somewhat distorted) during voice calls. I don't think its a hardware defect, but rather just the fact the top speaker offers 3D, surround style sound. I am having trouble hearing people clearly, something that never happened with my older phone. Also, I've seen posts on here asking about the same thing with the iphone X. Can someone tell me if this new speaker just doesn't sound the same for voice calls when on your ear? It's def a different type of sound and not sure how to describe it...