I must say, this thread has proven people can discuss a subject at length without someone pissing in someone else’s post toasties. Kudos to all.
My two cents:
Low (volume) level detail can get lost in noise, so chasing hum and AC noise can pay detail dividends. This detail can include pretty much the whole spectrum of frequencies.
Most of us (myself included) tend to think of detail or lack of as occurring in the higher frequencies in the realm covered by tweeters. Some mechanical aspects of tweeters impact detail like low mass (speed) and low distortion, but assuming quality tweeters, much of what we perceive as detail is driven by the amplitude (volume) from the tweeter.
In my experience contributing to speaker design a LOOOONG time ago, we could increase the volume of the tweeter and it would enhance the level of detail we perceived. Cymbals would shimmer, the attack at the beginning of a guitar note was addictively clean. Life was good. Things I had never heard were uncovered, like noticing the piano player was quietly singing along or tapping his toes to the beat. Percussion at the back of the hall on classical recordings was “right there” instead of smeared across the back of the soundstage.
However… we eventually noticed the downside to all this detail; fatigue. Whereas before our listening sessions often lasted long into the night, now we had had enough after an hour or two. On some recordings, in particular digital recordings, it felt like I needed to duck when a cymbal TING flew past my face. All this detail was masking the glorious midrange we had worked so hard to achieve.
Midrange is the meat and potatoes for those of us who love to get sucked into the involvement of great recordings where we look up and hours have passed in heady enjoyment.
Mercifully, I’ve come to my point. All speaker manufacturers deal with this balancing act. Hotter tweeters produce more addictive detail, but at the risk of causing less musical and more fatiguing results.
We as audiophiles can impact the balancing decisions made by our speakers designers with the equipment we choose, interconnects, room treatment, speaker placement, etc, but that’s a whole different set of subjects.