In a 5-ch bed layer, Surrounds should be 110-120º.
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In a 7-ch bed layer, Surounds are 90-110º and Rears are 135-150º.
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Height of Speakers depends on how many people might be in the "row." If you have seats with high back that can block the sound or have people surrounding you who can block the sound, it is customary to elevate the surrounds a little above head level (when seated) and aim them toward the MLP. This helps get unobstructed sound to more seats.