Is "detailed" audiophile code for too much treble?

All these responses are suggestive of mild synesthesia, where one sense spills over into experiences in another. In strong synesthesia, for example, some people will experience distinct colors for each word or digit they encounter. Here we have largely visual metaphors for aural experiences. Yet in synesthesia the visual experiences aren’t merely metaphorical. They are inseparable, in experience, from the reality.

There are some neuroscience researchers who suggest we’re all, at least mildly, synesthetic. But the thing about synesthetes is that where one person may always experience the number 9 as blue, to another it may be red. The experience is at the level of something objective; the reality is nonetheless a subjective one. Still, the number 9 is real, and different from other numbers. So the subjective perception of coloration is nonetheless accurate in indicating an objective difference in the underlying reality. It’s not just psychological. What comes across as a metaphoric expression points to something real, despite the problem this presents in creating a common language for the quite real and fundamentally accurate personal experiences of difference.

Back to the question, Is "detailed" code for treble boost? Yes and no. There can be more detail in presenting bass instruments, not just stringed, but drums, that has nothing to do with high frequencies, but everything to do with presenting the harmonics of the root frequency and the crispness of the initial contact on string or drum head so as to be true to the original. However, when presenting harmonics of higher pitched fundamental notes, going into the treble range, sure tweeters' capabilities and limitations come into play.

In my case, ratcheting improvement in each part of an increasingly componentized system, I've gotten to where it is more pleasing using the "Natural" EQ of a Yamaha pre-pro's YPAO room equalization, which rolls off the high end more than "Flat". But that from improvements elsewhere in the chain that have increased the detailing throughout the bass and mids (Emotiva DAC, Fosi V3 Mono amps with Sparkos op-amps, Revel speakers -- each an improvement on several generations of other models in those stations).