What music app and what normalization? Also, you might check and make sure that its not just at a higher volume which almost always gets perceived as "improved sound quality" in relatively direct comparisons. Also might make sure there wasn't other processing that got disabled in the process. Personally all of that stuff (surround stuff, etc that's really prevalent now) sounds "wrong" to me. People rave about Apple's noise cancelling quite a bit, and some of the other, and I guess its decent but it leaves everything sounding off. I can mostly ignore it when watching YouTube and other, but with music its really apparent and almost never a positive.
With Apple there's both a spatial audio setting but also a Dolby Atmos setting in like the Music app. I've heard that some Atmos mixes are really good but the ones I listened to just sounded like modern hotmixed cacophony of dynamic range compression and other.
I really wish Apple would offer an actual premium in ear, or would open up their wireless protcol so that others could use it. My IEMS are so much more enjoyable, do a good enough job of passive noise cancellation, and I could get good enough bluetooth battery life that I could actually keep them in all night and be able to count on them being able to