Speakers/system a bit bright?
Do you have a SPL meter? It’s my latest kick, wish I bought my own a long time ago. The question mark will disappear.
I learned a lot and made improvements with an inexpensive meter. I realized, they don’t need to be perfectly calibrated, they just need to measure relative differences, test band to test band. then see if too bright relative to mids, how the subs crossover effects things ..., see if slight changes of speaker location, toe-in, cables, anything are beneficial, detrimental, inconsequential (do one thing at a time).
.........................................
Meter on tripod, seated ear height, listening position.
test CD with individual bands, this one has 1/3 octave, each 1 minute long (not annoyingly short).
CD’s you can change tracks, pause, resume, much more convenient. No player? you could buy a cheap player just to do this.
or test LP for you, but then it is telling you what the cartridge, as aligned, is outputting, maybe that’s best for you anyhow.
I prefer using a CD, then comparing favorite music: LP version to CD version when refining cartridge alignment.
last thought: maybe they don't measure too bright, but you prefer less bright. meter will help you achieve that by confirming changes.