I should note here that I cross-posted this question in the Arendal Sound Exclusive Club on FB as it seemed more active at the time. Rather than repeat things said there I will quote the relevant comments.
Brandon (Arendal): Try toe in that will shoot each respective driver by the outside of each ear. Are you using sealed or ported and how far away from front and side walls?
Me: There really isn’t a toe in position I haven’t tried. I started out with them ported for the first couple of days, but am now using them sealed for better integration with the sub. As for positioning, I do have some placement restrictions. The speakers are about 36-inches from the front wall and about 16-inches from the side walls. This is roughly where every speaker that has been in my home has been placed since 1995. Not ideal, but it’s always been very workable. Obviously, some have performed better than others casting instruments well outside the speakers, while some retained the soundstage solidly between them. This is the first speaker that has drawn instruments to itself in this way.
Brandon (Arendal): since so close to walls, with the way the wave guide behaves, you can put some diffusion on that first reflection point followed by some absorbtion on the next panel and it works wonders. Here is mine .. but I have the towers.. (Picture not copied.)
Me: I have drapes on the left and an open doorway on the right. I do expect similar directivity characteristics with the S as with the bookshelf and also the 1723 Monitor as Warren Knauer (FB poster) called attention to. It seems to be consistent within the Arendal line. Not a bad thing, just an observation.
There are very good reasons why HT speakers may have a narrower directivity pattern than a speaker designed for critical music listening. My questions and comments are not intended to be a criticism, and I want to be clear about that.
I hear the phenomenon most noticeably below the x-over region where I would expect the directivity to be the most hemispheric and therefore less localizable. A floor tom in a drum set that might normally move toward one side of the soundstage from the center yet remain within the logical soundstage image, may sound disconnected from the natural soundstage and located directly at the speaker itself. It’s something I’ve not heard from any other speaker in the 27-years we’ve been in our home.