From a speaker output perspective, the in-ceiling M3s are enough "full range" to work very well. The current question out there is if they have a wide enough dispersion to fill a wide area of sound and not "spotlight" sound straight below. I am not saying that they are not "wide" enough, I just don't think that anyone knows yet.

Dolby themselves recommend slightly angling the speakers towards the listening area, and any in-ceiling speaker with doesn't have tiltable tweeters (at least) may have a problem in being "ideal." Again, I am NOT saying that the in-ceiling M3s won't work. The ability to tilt is to allow all speakers to work, so it is a general guideline that is more critical for speakers with a narrow dispersion. Is that the M3? I don't know, and there are only a few people on here that have them, and they haven't answered that question.

Farewell - June 4, 2020