Does the first reflection point actually matter??

@tony1954, we are more sensitive to localization clues in the horizontal plane.  Most of us have our ears mounted on the side of our head, not the tops and bottoms.  :)   So early reflection points on the side wall tends to be most impactful,  Back walls that are close to the main listening position can also be more impactful in terms of confusing localization clues.  In certain cases where a room is very wide or where the main listening position is well removed from the rear wall, floor and ceiling can be more impactful.  Conventional wisdom is that you would like to have all reflections arriving at the ear with a delay of 5 to 20 milliseconds down 20 dB relative to the direct signal.  Reflections arriving at the ear within that window tend to smear the localization clues provided by the direct signal.  Reflections earlier than 5 ms tend to merge well with the direct signal, and those reflections arriving later than 20 milliseconds tend to be perceived as separate echos adding to the spaciousness of the room. 

@gs5556 ....the Yarlung site was a fun listen with my diy Walsh, which already project a large soundstage by themselves. *S*

'Sonic holography' took me back to when I owned a Carver C9 Sonic Holography Generator back in the '80s'....It didn't work consistently with everything; whether this was due to the mixing, the format, my space and placement within....

....but, when it did....you almost felt you could grab the neck of the lead guitar...;)

1st reflection with omnis (or, for that matter, dipoles) becomes either a moot point or the 'sticky wicket'.  When 'all', or nearly, becomes reflection the room becomes part of your 'system'.  It can't be ignored.

My current space is so ghastly that all I can do is to reference the late Linkwitz and 'ignore the room'.  This consists of running 5.1; F & R, L & R, with a sub 'up front'.  Works best with 4 identical drivers in the corners....

I can add a slight delay to the back pair which can enhance, but it becomes 'selection dependent' and a PIA to do. *L*

But then I'm 'listening to the stuff' rather than 'listening to the music', which kinda defeats the goal of it all....and I'm pretty atypical in approach, anyway....

Best, J

Funny....Yarlung states their generator fits a 2U rack space.

Which is just about the size of the Carver units.....🤔

...and I've got room for 2 of them....;)

*Familiar opening music passage....*

"Space.....The Final Frontier....."

...some will say I'm 'spaced' enough already....*LOL*

YES!!!!!

If I recall...Richard Hardesty’s white papers claimed that first reflections from side walls are the most harming due to confusing the brain as far as timing.
reflections off the floor result in excessive brightness and reflections off the ceiling don’t affect anything at all.
in my case, the room leans towards bare and lacks treatment but I don’t find the resulting sound overly bright. Nor do I have a problem with bass boom.  It did take quite a bit of experimentation with speaker placement to get here. 
Erik, here’s a test: if you could swivel deadening/diffusion panels at first reflection point so they are not parallel to the wall they are mounted on....say 15-20 degrees ( closest side to speaker 4” off the wall and side closest to listener touching the wall) this should throw the reflection to the back of the room, away from normal listening positions in the middle of the room, would this mimic the openness of a staged hall? Sucking the sound out and around?