While I respect the Toole/Harman School of speaker design, I would not go as far as thinking it is the only valid way to design a speaker. There are other schools/philosophy/design concepts. People like Geddes take a different approach. Granted he did/doesn't have the vast Harman resources but his research is solid and backed by science and empirical results. The people at places like B&O and Kef do not seem to follow the same principles abide by the same principles either.
I do believe the Harman/Toole is a valid way. There are many
I certainly think there's room for flexibility, and it would be really interesting if more research emerged to contradict some of the Harmanesque findings, but I wouldn't consider the examples you provided as being particularly different from Harman - more like variations on a theme. KEF pretty explicitly says its views line up with Toole's research in
its Reference series whitepaper (Section 4.1.5), at least with regards to frequency response on and off-axis. It even provides spinorama data for a Reference 5 prototype, and it provides spin-ish graphs
for its new R series speakers as well
:
KEF Reference 5 Prototype Spins:
For Bang and Olufsen, I've only really looked into their flagship, the Beolab 90, but that one at least seems to be pretty harmanesque too. It too has a
whitepaper available, which is pretty massive, but reveals much of the design philosophy. Though there aren't frequency plots, it does say B&O performs some tuning to balance the on-axis and power response in room but the speaker actually includes a 'flat on-axis' mode in the software should you prefer it. B&O does show polar plots for the different directivity modes; the narrow and wide modes look pretty smooth.
It appears to be a ridiculously customizable speaker - not many speakers allow you to shape both frequency response and directivity. I'd love to see more speakers like this.
And my impression has been that Gedess generally agree with Toole in the grand scheme of things. The main thing I recall is he advocates for narrow directivity and Floyd prefers wide, but these are matters of preference
The speakers I'm referring to in my OP are more like the aforementioned Zus, some B&Ws, Devores, etc. In particular more expensive models where budget is presumably not a concern. Sometimes these speakers display measurements that are well far from flat on-axis and/or display some wonky dispersion behavior. I really am not passing judgement on these brands or individual speakers as I haven't heard all of them, but I'm genuinely curious as to the potential mindset behind their designs.
Also note that I'm not saying Harman makes the best speakers (I haven't even heard any of the Revel speakers, arguably its most lauded brand). I'm just broadly referring to the basic principles of flattish on-axis axis and smoothly changing or constant directivity off-axis that its research has backed up. Different brands will have different philosophies and will execute differently on just how flat 'flat on-axis' needs to be, the importance of reducing distortion, wide vs narrow dispersion, efficiency, etc.
EDIT: I now see two others have mentioned the KEF bit. Woops, that's what I get for not refreshing =]