Our way of hearing is not as simple as only receiving the right frequencies....although we are not like bats, it has become clear that our way of hearing is way more complex than a simple hearing test would indicate. A scientific experment some years ago clearly indicated that test subjects hearing a +20 khz tone could not point out the test signal "over" silence, but when the signal was added to another sound below 20khz, they could clearly indicate the difference.
I have always found it strange that audio lovers only look at their hobby from one end (specs of amplifers, speakers, etc) and forget about the complexity of the "machinery" on the other end - their own ears. Reasearch about deafness and how our hearing works, is for me as essential to this hobby as understanding what RMS, Ohms and THD stand for... This being said, there is no simple answer to how we perceive audio signals...but there's more at work than our ear drums - deep bass tones are rather felt than heard with our internal organs and skeleton, the highest frequencies seem to get their own interpretation as secondary harmonics, but also as some kind of complex spacial placement.
I have a pair of KEF hypertweeters in a separate enclosure, after testing and trying i ended up with a crossover around 17 kHz (just beyond my own hearing limit, AND I am 39 so all is not lost yet!!) and i have to agree with an earlier comment - vinyl records are spectaculary improved indeed, especially fifties decca et al. CD's get an extended hig frequency range, but stereo placement get blurred a little - which seems obvious since adding the tweeters transforms the existing stereo image into a different one - I may tak some time out to twist and turn my speakers a little, but only when the wife's away.... Analog instruments but also hammond organs get a fuller, more separate placement between the other nstruments, electronic music seems to become more "crowded".
I guess in the end that using supertweeters has it pros and cons, it is sometimes a trade-off, but i see a definite future in the concept.
This is my first comment on this forum, and I hope my comments contributed a little to this interesting topic.
