In reply to:
Under this hypothetical situation, could it be possible that a different tweeter design, that would re-produce sound with the same frequency response characteristics, but possibly made of a different material, would reproduce those “detailed” sounds me all love, but yet not have exude any sibilance?
The frequency response
is the sound. What you're asking is impossible. Not all sibilance falls in the same frequency range. A little googling told me that sibilance, especially from vocals, falls in the 2 to 10khz range. So to design a tweeter that de-emphazised sibilance you would need to depress quite a wide range of sound.
I would rather use an EQ that I could turn on and off at will rather than be stuck with a speaker that veiled my highs permanently.
