Which is bizarre in that it is so vitally important an attribute/feature for a coned speaker with multiple drivers for various frequencies.
Apparently not. I have to say, I am one who has hear Vandersteen and Thiel and not found this attribute so overwhelming. The marketplace agrees with me.
Mind you, a well designed, multi-way speaker IS phase and amplitude aligned. It is not however necessarily time co-incident, which is what Thiel/Vandersteen and a handful of other multi-way designs attempt.
If you like it, that’s fine, and if you think it is a must, well, OK! But the market and my ears have not felt this is an overwhelmingly important attribute. If it were truly an overwhelming advantage others would do it too.
Best,
E