speakers already have a dispersion pattern but for Atmos a lot depends on your ceiling height. For 9ft ceilings like mine you don't need as much angle if any. The in ceiling m3s have an adjustable tweeter. Other people have angled on wall speakers if they have lower ceilings.

M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85