Listening distance first
The farther the seat, the more acoustic output the loudspeaker must deliver for the same level. The farthest critical seat often exposes whether a compact speaker has enough headroom.
Room volume changes the load
A large volume does not automatically demand one specific driver size, but it changes bass loading, decay behaviour and the amount of acoustic energy required to create a convincing sense of scale.
More rows change coverage
Multiple seating rows can be a directivity problem before they become a raw-output problem. A speaker that is loud enough may still fail to cover the rows evenly.
Screen width and LCR spacing
A very wide screen spreads the front channels apart and can increase the listening distance to left and right speakers. That affects both output and toe-in requirements.
Choose for clean peaks
The right speaker is the one that meets target peak level with low distortion and sensible reserve — not necessarily the physically largest model in the catalogue.