I'm not saying I would want a speaker that rolled off at 15khz, I'm just saying, if you can't hear over 18khz, whats the point of being concerned about a response that goes to 40khz... Don't sweat it Curtis.... I love my RAAL's and wouldn't trade them for anything !! I'll take my 20-20khz, but beyond that is just worthless for companies to even pad their specs with... There is no-one PERSON that can hear that high... I'm going to buy that tweeter so I can piss off all the local area animals... !!!! I also agree that you're not going to hear any of those frequencies at the top of the spec sheet. But the RAAL goes as high as it does because the ribbon element has so little mass and because the whole driver is beautifully engineered. I think it's those factors, couple with its almost line-source radiation pattern that provide the effortless and wide open character that is immiediately evident in an A-B comparison, even to my tired old ears. I don't think it's because we're taking in 30 kHz tones through our sweat glands.