There is so much misinformation about horns. I wonder if it came from folks, years ago, hearing Klipsch speakers with bad solid state amps when SS was new.
Certainly there are horrible cone speaker systems, really bad planars have been made, and there have been bad horns made. Why do horns alone seem to be saddled with prejudice about "harsh sound"? Maybe the dynamics of horns make bad ones stand out more than bad cone speakers.
In the case of the 1400, look up the Stereophile article. Reviewers often get things wrong, but the reviewer describes the 1400 well. He loves them. And he's comparing them to Quad electrostatics! And yes, there are some similarities (I have owned both speakers) The 1400 are smooth, natural, great on voices, great on a wide range of instruments, very nice dynamics (seeing off nearly all cone speakers), great driver integration. They do NOT quack, honk, zing you in any way. Behind a curtain nobody would be able to hear a "horn" sound. And they go DEEP in the bass, JBL certainly knows woofers.
If I had to assign a "coloration" from neutral, they are slightly warm, a bit on the "natural" side.
A very, very well balanced speaker. A bargain, in today's crazily-priced speaker market.