Very interesting topic, Jan.
I too have pondered and looked at ways to expand the sound field vertically in order to achieve the best possible sound (or better said, more realistic sound). As you say and I too have come to realize, there's much height to the sound you hear in a real church that I felt I was missing at home. You go into a larger church / cathedral with a good acoustic, and depending on where you sit the sound of the organ also seems to come from a higher position and above, in some cases almost like a surrounding sound that's raining down on you. It's a very pleasing effect that I've wanted to duplicate at home, but has alluded me in the past. It isn't possible to me anyways having speakers positioned just to the front and the rear to achieve this as I've tried everything (including standing on my head

) with results that haven't done the job, and to me we are leaving out an important part in the sound by taking the front / rear speaker only approach. What got me thinking on a new method is I've taken a cue from a few of the local movie theaters we visit from time to time, and have noted how they position speakers, both in front, and also to the sides higher up along the walls which gave me an idea to try. I'm in a fairly small space of approx. 10' wide by 12' long with a ceiling height of just over 8'. My theory was to start by keeping my front and rear speakers as positioned but also add one pair of speakers up high near the ceiling directly off to my left and right side to fill in that high vertical and off to the side sound which I can control the volume of and also choose which part of the signal I send to these speakers. I've tried sending the rear / surround signal only to them which is the most distant signal, but have found so far that a signal mix of all works best (with the exception of direct not being included). My theory being by the time the sound travels so far in the large church coming off the ceiling and sides, the sound is becoming more distant / dispersed sounding, but not like it would be if you stood way at the back of the church, so I'll call it the mid somewhat dispersed signal. Then, with careful volume adjusting from there it opens up the vertical sound field considerably. I'll put it this way, since I've implemented this arrangement I won't go without it. Not exactly what you have in mind of recording a high and somewhat distant position and then having the option to send it to another pair of speakers positioned in a certain way, but then I do wonder doing that and what I'm doing if it would make that much of a difference. I've contemplated adding a second pair of side speakers and positioning them off to the sides again near the ceiling and just behind me, but I wonder what benefit it would add or if it might then detract from the overall sound.
I think part of the key to making it work is setting things up as you would imagine yourself sitting in the church. I try to strive for a sound that would place me virtually about a third of the way back in the church from the organ.
Interesting topic for sure and I'm always looking for new ways to improve the sound.
Marc