I agree completely. However, that is a markedly different narrative from "Both KEF and TAD speakers suffer from Intermodulation Distortion since the woofer or mid cones are the waveguides. While it is true that their off-axis radiation it symmetrical, the design also limits dispersion at the highest frequencies, which is heard as a lack of "air.'"
Speculation of a long-standing Harman blind spot about concentric drivers is "idle chatter," I agree. But I heard similarly dismissive comments about concentrics due to IM distortion from ex-JBLer Greg Timbers last decade, so...
To be clear, I am NOT making the argument that concentrics are inherently better than a thoughtfully engineered multiway speaker with a waveguide-loaded tweeter that matches the dispersion of the next-driver-down at the crossover region. I'm merely pushing back on comments that they're inherently worse.
I'm also very skeptical of the IMD argument. Not that it's there. Clearly it is. But is it audible and consequential? Mitchco's earlier post
includes a link to his article
comparing the KEF LS50 and a JBL Pro speaker with a 15" woofer and compression driver tweeter. This review includes binaural recordings of the LS50 full range, LS50+subs, and JBL + subs. Can someone point out how the inarguably much higher IM distortion in the LS50 manifests itself in these recordings?
Lastly, there is one company selling a speaker line based on a concentric with flat midrange today: Technics. Within the limits of what one can discern from Stereophile's measurements - no sign JA's dumb practice of normalizing his off axis charts to the axial response will end, alas - the bookshelf model seems capably engineered if voiced very bright.
For those following along at home: Kindle Location 9362 (pg. 448).
And, yuck. The midrange level jump does make me wonder if the Alnico woofer had been partially demagnetized at some point. So glad we've moved beyond Alnico!
Business realities and IP law do get in the way of that to a large extent, of course.
Other companies and individuals have made a certain drivers a large and perhaps dominant part of their business identity, and as a practical matter following them would imply that they were "right" and the previous products were "wrong." Just look at what happened to Thiel when they abandoned some idiosyncratic design concepts. There were other factors involved there, but undeniably one of them is that "Thiel buyers" hated the upgraded design philosophy.
As for IP, to use a speaker example: if multiple-entry horns are a superior technology - I'm not saying they are, just using them as an example! - then other companies are limited more by their willingness to license technology (and the IP holder's willingness to license) or risk litigation on their patent workarounds.