Klisch Cornwall, Audio Note UK AN-J, Auditorium 23 755

You are trying to compare three very different speakers, and you haven't told us what you like or don't like about your existing Klipsch Fortes. If you like the Forte sound then the Cornwall IVs would seem to be a no brainer - Fortes on steroids.

The Audio Note J is a very different speaker. Much more polite delicate than the Klipsch and will sound absolutely bass shy, compared to the Cornwall. If you like one I doubt you would like the other, in the same room and with the same music. Maybe an AN-E SPe?

I haven't heard a pair of Auditorium 23 755s for over twenty years so I will not comment.

I understand where br3098 is coming from, but discussing the characteristics/use cases of very different speakers seems to me more useful than quibbling over minor differences of similar ones. For the latter, the ultimate decision would likely be more personal, with little need for forum debate.

The non Klipsch speakers are significantly less efficient, to the point where your 8 watt tube amp will struggle to fill the room like the Forte does let alone the Cornwall.  I like my music loud, and even when I’m not listening at loud levels I like to know my system can get there if needed and while it’s not a large room, it isn’t exactly tiny either.