|Hi Keith and congratulations for your new babies... I'm truly jealous of your room size.
Me too, as I previously wrote, assembled a VERY similar rig, vastly inferior to you welded supports, any, using the same approach: S-150, S-3000 and S-400, respectively mid-low/tweeter/mid-high.
I fiddled for weeks, with several angles from extreme 110°, back to 30°, staying at about 70°... consider my listening room is ONLY about 25 square meters and I'm listening on the long side (see pix).
The reason of my post is: yes, I took my time to toe in and out speakers, moving voices of some inches, trying to blend bass enclosure, flipping it 90°, playing with my Phonic gear to obtain a smooth emission fro each voice... BUT, all said and done at the threshold of my patience and interest for the thing, when I re-assembled the 4 ways in a more conventional way, I must admit... all my "new", "revolutionary" ideas in speakers positioning get tamed.
It has been a quite entertaining, amusing, different audio adventure, but being at about 190 cm from the horns front, ears to horn-mouths, I'm sincerely enjoying a quite correct, musically involving, right in size and dynamics rendition... a sort of single speaker, a wide-band listening with much more air, details, trueness.
Maybe, and I'm asking to Roman, am I too near to speakers to appreciate the full benefits of a different alignement (or whatever I experienced in the past weeks...)?
With an horns mounting like Keith's I heard something not so cohesive, full-bodied... also details and center imaging were, in comparison to the actual rig, quite unfair to my ears, I can say now.
I'm pretty sure that horns aren't only for large rooms: the best detail retrival I ever heard happened in my room and in another 20 sq. meters room... I recently measured with my (humble) Phonic PAA3 Audio Analyzer an SPL range between 40 and 98 dbV/A at listening position, with no pain at all, being able to chat with a friend without shouting.
I'll sure won't stop experimenting, but that's what recently happened in my music room... maybe more traditional horns positioning someway "clicks" DPoLS-wise in my room, Roman?
I don't feel me like I gave up in experimenting, BUT like I found a nice aequilibrium.