It's pretty constant throughout the tweeter range:
Instead of narrowing like most speakers. That's why moving around generally doesn't cause the sound to change.
They aren't a RAAL ribbon in the width department but that goes without saying.
Right, I get your point. I think Amir’s directivity plot was a little less flattering, but it certainly has constant directivity above the xover.
Compared to the SC307 with the AMT tweeter, the S400 is not as wide, as you say.
My experience with these two speakers side by side is that the latter throws a bigger, “deeper” image albeit still with a precise phantom center, just not as pin-point as the S400. Both are enjoyable with natural timbre, but in different ways.
But I’m relatively new to all this, so still learning to interpret the graphs correctly