KEF In Wall DIY speakers, help needed.

[Launagis]

I've decided to open a new thread. The backstory could be found here:

Sanity check - LS50 Meta vs In Wall speakers

Hi all. I'm trying to make my new house work for audio, and I'm almost there, but i just have this annoying vision of putting In Wall speakers, well, in to my walls. One problem is, that one side of the wall is open, and it is open where i should have to mount the speaker. So my general question...

www.audiosciencereview.com

TLDR version: asymmetric room, was choosing between bookshelf speakers and "in wall" speakers, tried bookshelves, SBIR is a problem, now want to move "in wall" route.

I've got into concentric/coaxial loudspeakers quite early, got Tannoy D300, upgraded to D500 - liked them very much, but since I bought a house they just would not fit. So I sold them and got KEF LS50 Meta. And now I've sourced KEF SP1632 drivers from KEF Rx00 series.

My vision:

Since walls are drywall/plasterboard and have empty space inside them, it's not difficult to mount some speakers/boxes inside. Thinking of pairing them with 1 or 2 woofers per side, Dayton SIG180-4 if the main candidate right now. Also, I have access to 3D printing and CNC stuff.

I'm not very gifted academically, but I read a lot, try this or that, and usually succeed. For example, I quite like my 4 DIY subs I've mounted in the furniture. But right now I feel that I hit the wall and can't go forward without some guidance. Concerns:

1) The wall is good on the left side, but is open ended on the other. As far as I can understand, on the right I'd be losing something like 3db in the lower midrange/bass due to half of baffle step loss? Should it be of a concern, if I could EQ it through AVR, also leaving deeper bass duties for subs? Any other problems I don't see?

2 TV between speakers is extruded 35mm from the wall. Should I make new baffle to be equal to the TV surface? One baffle itself could be 1085x540mm. Other option would be to mount speakers flush with the wall.

I have more questions/concerns, but for now I don't want to overload the thread from the get go, want to see, if it gets from the ground at all. ANY help would be greatly appreciated.

Tagging KEF heavy hitters @Zvu @Nusse

Some sketches I've made with Fusion360:

Room layout:

 

[Sokel]

The main problem is not the speakers,any speaker,you already know that.
And it's not the wall the speakers will be in (or out).

The problem is the asymmetry plus this rectangular space to the right of the couch who adds to the blocking of the right side reflections.
The only thing I can think of is treat this side reflections to the point they become totally insignificant since they can't match the left side ones which will be greatly attenuated by the distance to the left.

I you address that successfully,then you can explore the speaker options.

 

[Launagis]

The main problem is not the speakers,any speaker,you already know that.
And it's not the wall the speakers will be in (or out).

The problem is the asymmetry plus this rectangular space to the right of the couch who adds to the blocking of the right side reflections.
The only thing I can think of is treat this side reflections to the point they become totally insignificant since they can't match the left side ones which will be greatly attenuated by the distance to the left.

I you address that successfully,then you can explore the speaker options.

This is a very good point, and I'm aware of this problem. Before starting with this system, I knew nothing about room acoustics, now I know a lot.
1) I have a plan to put more absorber on the left side of the ceiling, thus absorbing more reflections. Extreme case:

2) Unfortunately, I can't put absorbers on the walls on the left side of the room, since there is a big window next to the couch and kitchen furniture near the wall.
3) I also thought about movable "gobo" absorbers.
4) Restricting radiation from speakers itself would be an option, but I just don't know enough how to do that properly. One sketch shows both baffles angled inwards exactly for that reason.

The room problem will remain in both bookshelf or in wall speaker scenarios, but I still have the benefits of "eliminating" SBIR issue and improving power handling with in walls.

Regarding the sound in the room right now. I balanced both speakers with pink noise - closing my eyes and pointing finger to the acoustic center till I got it dead center. This improved things a lot, and with most tracks I would call the sound acceptable. Adding to the mix good extension from subwoofers, I would call it enjoyable, even. Problems occur with tracks, that have "spatial effects", "aura" or whatever you call it - then the "cloud of sound" moves left, in some cases dramatically.

Photo of current absorbers: