There is almost no musical information at 18 khz, especially since most adults can't hear over 15 khz anyway. And that is a pretty good range for a driver/horn combo.
Yeah, I guess you're right, I was just kind of surprised it rolled off like that. I do think that upper stuff lends a sense of air and openness, but no real information there.
I'll check my inventory to see if I have any left, If not check with Colin Hester here on the board, I sold a pair to him a year ago and I think he switched to something else. There's somebody else on the board here that has quite the Altec collection, but I forgot who. But I'll let you know next Tuesday if I have any left. Bill W.