Been mixing an album for about a year. I have most songs where they sound great in car, Bluetooth, earbuds, speakers etc. Every time I listen to it through phone speakers it sounds weirdly harsh and washy - especially in hi hats and vocals. The only solution I’ve found is to dull those upper mids/highs - but then it sounds lifeless on any other speakers.
Not sure how professional records were able to achieve brightness that doesn’t sound harsh on phone speakers, but many have.
Note: My mixes sum to mono with little phase issue - at least according to meters.
Note2: this is not mastered, just mixed
Appreciate any thoughts or tips appreciated - as this has been relatively frustrating.