Well. Hard to say for certain but Dolby does have a recommendation of at least 1.2 meters away. So let's start with that.
It seems the person above disagrees with Dolby specifications of the angles for atmos speakers. And 99% of feedback I've seen to date has people raving that those angles work best!
It seems the person above disagrees with Dolby specifications of the angles for atmos speakers. And 99% of feedback I've seen to date has people raving that those angles work best!