Preserves the amplitude of fundamental harmonics, which are well within the average person's hearing range.

Here's a white paper on the subject:

http://66.102.7.104/search?q=cache:uicyBsZzhysJ:www.tannoyna.com/professional/pdf/wp_wideband.pdf+why+supertweeter&hl=en

Enjoy the Music. Trust your ears. Laugh at Folks Who Claim to Know it All.