Guinness Book of World Records 2009 states that asthmatic children can hear up to 30k hz! Time to hire some wheezers for consultation. aa
Hey!
This might be off topic. But this sure proof that Super tweeter can have impact on overall sound, with source that have respond that high like SACD and yes LP.

And also why CD sound unnatural because there is nothing above 20khz (or was it 21.5khz?)
I don't think I can hear that high but when I play test CD at 20khz I could hear it, at lower level and sadly better on my left ear than my right

Take care,
Buddy