This is even more frustrating!...
When saving the pennies for my AltitudeCI I also made provision for buying
KEF Ci200RR-THX in-ceiling loudspeakers.
My detached home is brick n' block constructed with a 7cm wide beamed ceiling in my lounge. It was completely redecorated two years ago. On watching this
installation video for in-ceiling speakers without having to lift the upstairs floor panels, I felt assured by my dealer's advice that they would drill/run the cables through the outer brick wall, run the cables via external conduit to ground floor level, and in through the wall to where my Meridian 258 would reside.
I bought a
Bosch Inspection Camera to determine which way the ceiling joists ran, and a separate
Bosch Stud Detector to determine the space between joists. My beamed ceiling runs across the width of my lounge, and, as the Stud Detector revealed, the joists run the length of my lounge.
Post purchase of the AltitudeCI, and once they had learned about the direction of the ceiling joists, my dealer bailed on installing in-ceiling speakers, as they would be unable to drill through the final ceiling joist/outer brick wall.
Before you suggest it, I don't want to run unsightly trunking down the internal wall.
The dealer's current suggestion is to mount satellite speakers under the ceiling beams, run the necessary cables hidden behind the beam/s, and then drill through the brick wall. Their other solution was to just use it as a 5.1 system (!).
I subsequently investigated possible options by Focal, B&W, Epsilon, and Cabasse. The least worst option is to install
Gallo A’Diva SE speakers aimed at the MLP via Gallo's 4cm wide pivotal wall mount. I used ChatGPT to illustrate the reality on how they would look in situ, and, while they look acceptable, it's at best a sub-optimal alternative to discretely installed in-ceiling speakers.
I've spoken to Gallo for their advice: while the A'Diva SE is not a suitable full-range speaker for the Meridian 258 in 'stereo configuration' A'Diva SE is more than suitable as an Atmos speaker.
I am a tad irritated at having purchased arguably the best AVP on the planet that I'm not able to find someone with the skills/abilities/tools to install in-ceiling speakers in my particular home. If found, that dealer will get my business for 4 x Atmos speakers, even if they aren't by KEF.