In fairness to Dickinson (though I don't feel particularly charitable toward him) he was writing for theater owners and installers to convince them that the old stuff didn't have to be replaced to continue to provide satisfactory service - I don't know if Dickinson has the horsepower or not, but he might have written differently if it was written for speaker designers.

Me, I got no horsepower whatsoever. While I'm trying to digest this I want to ask a follow-up question: are these issues addressable by equalization? Not many active XOs (until the digital revolution ) had selectable slopes, etc...

Or put another way, is EQ a brute force way to address the kinds of things you're talking about with active analog XO that would be better addressed by the use of digital EQ that can be highly tailored?

Hope that makes sense?