room size question.

After trying all this , maybe acoustic pannels ( diffusers-diffracters , not absorbers )

on the side walls .

you may also try the distance between your speakers , be 83% of the distance between you and the speakers.

Virtual system about your room could help.

GIK Acoustic gives free advices according to your room’s measurement

I don't want to assume what you are thinking, but so far:

you tried everything with speaker placement and seating position and volumes

room is treated

it's a decent size room

it should produce a soundstage

your layers are either not produced or something "eats" them.   

you think it's your room size. I think it's synergy and I assume it's the lack of, between the speakers and the room. (and I hope this will be the lamest, most useless comment you will get today)

I sympathize with OP’s frustration here, as I have at times experienced a similar confusion about what exactly a deep soundstage should sound like and wondering why I can’t get whatever that is. I hope I am not being overly reductive or patronizing when I suggest that some part of this kind of confusion may come from not having a baseline expectation to work from - and instead imagining what is probably an unrealistic representation of a staggeringly deep, almost surreal soundstage that extends dozens of feet beyond the speakers. After all, that seems to be what many fellow audiophiles have, or at least are able to describe having. I have never heard such a thing in my own room, though - which isn’t to say it’s impossible, but that my particular room/system/setup likely precludes achieving it, which would seem reasonable considering the compromises I’ve had to make. The somewhat confusing psychology of not being able to achieve the perfect soundstage sometimes leaves my brain suspecting that I have no soundstage at all, and that what I’m hearing is just a pleasant but flat centered image. That psychology can be so powerful that it makes even a perfectly reasonable soundstage seem dull. A third party observer who came over to listen might completely disagree and think it sounds great.

I think I have just invented the theory of general relativity of soundstaging.

@maxwave 

GIK Acoustic gives free advices according to your room’s measurement

which i said in the very beginning :

GIK bass corner traps in corners behind speakers, 2 diffusors on stands at first reflection point and 2 acoustical panels behind listening chair .

@grislybutter 

I think it's synergy and I assume it's the lack of, between the speakers and the room.

 You think maybe a different speaker is needed ?     

there are diffusors on the side walls and cant hang anything on either wall as the wall to the right, a different size would be needed as that wall isnt very big ( a panel would cover the light switch ) and on the opposite wall, there is a window.    

.   

bshaw

When a question is asked you receive a lot of good information to try  ,

I'll give you something exact to try or not , I've already suggested having the speaker 36" from the side wall leaving your speakers at 62" from center to center, the next suggestion is based on the listening angle that is equal to the angle of the speakers being 8' apart and the listening distance being 10' or 48-49 degrees , so if you can move your speakers and even your listening chair so you have 75" from speakers to ears ,  now measure from the center of your listening position 23" and aim the speakers to that point .  Toe-in even just 1/2" will make a big difference , I know you said you didn't like it but I have moved my speakers several hundred times ( it's free ! ) and for me this formula is the best , but it will all depend on how things sound when you move the speakers closer to the front wall .

Good Luck