There are many products that are a bag of mixed compromises to come out with a semblance of neutrality. These "band-aid" products never can be as good as a design that does not use matching colorations to cover up errors (or compromises) in design, as each resonance or distorion destroys detail which can never be recovered. Only the tonal balance can be brought to a more realistic balance, the lost transparency and detail is lost forever.
This is the type of product an above poster is referring to when he says "Part of the art behind a successful horn is incorporating its colorations in a way that is consonant with the music rather than at odds with it."
He should have said "part of the art behind salvaging a flawed design and making it sound OK is .......at odds with it."
There are horns whose diaphragms are under control, whose throat design is good, whose phase plug really works with the design, and whose horn is correct for the frequency range and is non-resonant. These designs measure very low in distortion and need no band-aids such as the poster describes.
So many posts like that are garage pontification by guys who are not designers, who do not know the physics and math, who don't design high performance products, who don't have a multi-decade background of cause/effect experience by testing their own designs as well as those of others to go with their physics or engineering background, yet write as if they do know it all. And their posted information is very misleading, although their original intent may be good.
Proper horn drivers can be exceedingly low in distortion, and as a result sound sweet, smooth, yet highly detailed and dynamic. Playing around with some putty on Klipsches and making category-wide statements proves nothing. It's merely anecdotal at best, pertaining to a limited number of speakers that are far from state of the art.
Get a good listen to some really well done TAD systems, Tannoy studio monitors, JBL Everests, JBL 1400, Classic Audio Reproduction, Magico horns and you'll hear a wide variety of sound whose traits don't conform to the type of horn colorations that a couple of posters are saying are a fundamental trait of the driver type. These claims are not true. Note that Klipsch is not on the list. I don't want to offend Klipsch lovers, they do have their strengths. And the mix/match game might be able to achieve a nice sound. But most folks' gut feel about horns comes from experience with Klipsch or Avant Garde being driven by solid state, or from lousy, over-driven horn PA systems.
I have no monetary connection with horns, I don't sell them, I own some very expensive non-horn speakers, my list of 5 best speakers on the market include some non-horn designs.
Rather, I'm interested in super high end reproduction from any type speaker, and getting good information out there.