There was another thread on here with a link to a home theater YouTube that discussed Atmos and home theater design.
It also went into the description of how speaker setup and sound stage gets processed in the HT environment.
On the understanding of how Atmos is implemented inside an actual theater, the word that I got was that if you are moving to a 9 or 11 channel implementation, that you will get a far better bang for the buck putting in a front wide (9) and only 2 ceiling speakers (11) as the mixing will minimize the dead sound zone between the front and surround in any sound panning. The comment was that you will see that far more than any overhead sounds in most movies.
The other rather interesting bit was the description of how surround sound is handled. In the theater you have an array of side speakers. In 5.1 and 7.1 mixes, these arrays are handled as one so the same sound comes out of the array of lets say 5 speakers. To ones ears that is a large defuse sound. Under Atmos, there is the ability to address each of those same 5 speakers individually. That does give you either more control over a sweeping pan, or to accurately define a location, but you still need to remember the theater has 5 speakers. In your home you have ONE.
This sort of gives you a choice. Do you want that one speaker to be a large defuse sound that covers a large area, or more pinpoint accurate with large sound holes between the front and rear surround speaker coverage? Unless you are putting in multiple side surround speakers in your implementation, you will loose sound coverage to gain accuracy. That is a choice you need to make.
The Dolby spec need to be taken with a grain of salt as you look towards what will give you the sound that was intended and also you enjoy.
I experienced a CEDIA 2014 demo (when Atmos was demo'd for the first time), where they did a 9.1.4 setup and people asked about the front wides, and (I wish I remember the manufacturer/vendor) the guy said that they actually have a lot of preference towards a 9.1.2 setup OVER a 7.1.4. I believe that I posted that here at some point. All I know is that the 9.1.4 setup was really impressive, then again, there was something like $25,000 just is audio processors to do it, plus amplification, etc at the time.
I also agree that the Dolby specs need to be taken with a few grains of salt. I was in a discussion in a home theater group on Facebook just last week with a senior sound engineer about a few audio topics, and he at one point even mentioned that specs are put out there for creating a "target to shoot for" and that things are more flexible. At one point he even stated that a speaker (implied to mean Atmos ceiling speaker) could be even 10-20 degrees out of Dolby spec for location placement and still yield 95% positive result. Things are pretty flexible, up to a point, and then they drop into the toilet (my words, not his) pretty quickly.
I am on the verge of experimenting even more with my side surrounds by moving them to be slighting in front of my front row of seats. I find that the surround field effects are AMAZING in the 2nd row seats in my theater, but I like sitting up front, so I want to put my front row into that same large surround soundfield. I would think that this could be deemed unnecessary if I installed some front wide speakers instead. It was this discussion about putting side surround in front of the listening position and how that went against Dolby (and others) spec that started the conversation with him about the flexibility available, particularly with Atmos.
