Sennheiser AMBEO Instruction Manual page 17

Optimum positioning
Schematic structure of the sound waves from the Soundbar, which
are reflected by walls and objects and thus reach the optimal point
("sweet spot"). Thus, a virtual surround sound can be created with a
Soundbar.
30°
Object Meaning
Reflecting surface
TV
Soundbar
Furniture/curtain
Optimal point "sweet spot"
Sound waves of the loudspeakers
Sound waves from the top-firing loudspeakers
to the ceiling
Installing the AMBEO Soundbar
20°
AMBEO Soundbar | 17