Maybe it's my english, I mean in everyroom it can be different, but a anechoic flat speaker have best chance to have in room balanced frequency response, but yea that's why you need room treatment and in room calibration for professional use like those studio brands do to their top tier DSP lineNot really Erins in room measurements show there is higher energy in the highs vs the mids.
this sounded really counter intuitive to me and sounded just like: "if I have a reference colour chart, no matter how much my monitor deviate from actual colour I can always tune my photos accurately for print out"I don't know if you have experience with music production, but I can tell you that ATC speakers works very well for that application.
The most important aspects is that the mixer feel comfortable with the sound and have a good knowledge of how good reference recordings sound on the speakers. No matter how extremely detailed the sound is from the system/speakers, it’s a risk that the mix will end up having a wacky balance if no reference material is used now and then for re-calibrating what is heard.
In short: If the mixing engineer finds his speaker has a good balance (no matter of balanced) listening to good reference material, the result will also be a well-balanced mix.
the good reference recordings are more or less just what one get used to, sort of like how a colour chart works in photograpy. but those never covers all frequency spectrum. I think you missed the point of "detail level" in speaker, in my knowledge unless the speaker have very high IMD which masks individual tones, everyspeaker have the same notes reproducing in the music, just the balance (relative level) of individual notes, which is also what they tune or rebalance (mixing) among their workstation, one would like to have the frequency response as linear as possible by all means in room to have that done right. If limited to the usable FR range of my phone speaker, those top speakers don't contain more detail as in extra notes being reproduced, just they are more balanced (i.e. the speaker FR don't modify the original, which is by definition the most balanced/natural/factual sound)