I always thought that the Sara was the odd one out in that range. I had active and passive pairs many years ago and found them to be quite difficult to get right; they are pretty room sensitive, and if you get it wrong, the bass can sound bloated.
Same here,,I did not get along with Saras at all.
The Kans always surpised me in how deep they got down
within their limited volume,,keeping their size in mind, this was really
mindblowing at times.
But what I liked about them, they did not even try to be something they cannot be, so their bass...or whatever they did in the lower section, stayed clean.
The Saras appeared to walk around with blown cheeks to my ears permanently & seemed to aiming to pretend they were Isobariks.
W/o much success, of course.
The Isobariks in best case sound like Kans with bass.
Lots of effort to get them there though, as they are power hungry, as are the Kan.
Did you try something like the 250 on a Kan once ?
According to some that can be quite a shock...might be worth an experiment if you can steal or loan one anywhere.
And finally there's an Ergo attempt on the Kan, a speaker that looks pretty much a Kan from the front, but with more volume due more depth
and also more modern chassis making use of todays technology advances.
Haven't heard them myself, but some around here have them built or ordered and are quite happy with them.
So I have little doubt they are very good.
orangeart from PFM can provide the woodwork for these if my mind serves me right..
p.s.: ...Mark is keeping up with his nasty tradition of posting my wisdom 3 minutes before me,,,
I gotta buy something from him at some point , if only to bribe him into stopping doing that..