I guess I was under the impression that most theaters just used one giant horn loaded speaker for LCR behind the screen. Do some use 2-3 center speakers?
Was the 3 center speaker a thing of the 90's? I've just never heard of that until this topic, recently.
I know today some higher end AVR's allow for height speakers (non related to Atmos) So you could put 2-3 height speakers above your screen that are angled downwards at the seats. Same can be done all around your room. Put them above your side speakers to work that "middle" area between sides and Atmos.
I think those lovely Altec and JBL speakers were outed a long time ago.
With the size of a cinema three "centers" makes sense. A cinema is a very different space to a home space. In addition pro Atmos mix for a cinema and the one for home use are totally different animals. The cinema mix can have 32 ceiling speakers for instance.
But the issue is, that if you start placing speakers within six feet of each other or less, you are setting yourself up, for unintended interactions, including comb filtering.
I like to keep an 8' spacing between speakers.
Even Dolby recommend only four ceiling speakers for all but the largest domestic space.
I followed Dolby specs and recommendations to the letter, and it works perfectly, with objects moving seamlessly in and around the room. This is a case where more is not likely better.
There are pro designers doing a lot of things in domestic spaces, running up the bill for no good purpose and actually likely creating chaos.
