informal survey: how many Atmos users adhere to Dolby height speaker layout and performance recommendations?

[krabapple]

Here are Dolby's 2018 Home Theater Installation Guidelines*
I'm breaking their height speaker recommendations into four key points.

1. Ceiling vs front wall mounting and directivity: All of Dolby's diagrams (except ones using the bouncey Atmos Enabled floorstanders) show height speakers mounted on ceiling and firing directly down.
For this to work well, Dolby recommends them having a 'wide dispersion pattern' (They do not specify vertical vs horizontal dispersion)
If they aren't wide-dispersion then the speakers should be aimed a bit toward the MLP rather than firing directly down.

2. Left-right placement: Dolby figures show left-right placement as being in-line with the FL and FR speakers.

3. Front-back placement: Dolby shows recommended front-back placement a bit differently depending on whether 2 or 4 height speakers are used
-- for 2 speakers, anywhere from 65° in front to 110° behind (where directly overhead = 90°)
-- for 4 speakers, anywhere from 30° to 55° for fronts and 125° to 150° for backs

4. Frequency response: Dolby only says:

Dolby Atmos audio is mixed using discrete, full-range audio objects that may move around anywhere in three-dimensional space. With this in mind, overhead speakers should complement the frequency response, output, and power-handling capabilities of the listener-level speakers. Choose overhead speakers that are timbre matched as closely as possible to the primary listener-level speakers.

(At least one study says height speakers that go much lower than 400 Hz are probably overkill.)


Perusing various room photos hobbyists kindly provide here on ASR and other forums, I see much evidence of philosophies about this that appear to differ from Dolby's.

So I'm curious, who's actually adhering to this, who's not , and if not, why?

(This constitutes research preceding my own Atmos setup attempt)





(*have these been superseded?)