While every event does not dictate elaborate detailing of the layout of electrical outlets, best/safest cable runs, acoustical considerations, and more... some events do. Albeit to compliment guest/audience seating arrangements, maximized viewing of videos and slideshows, limited power outlets, etc., some audio-visual setups greatly benefit from a venue site survey and detailed diagramming of the recommended audio and visual setup. See the three I3) provided examples.
Designated Deejay Ent has executed simple to more complex set-ups including interior dual level, dual level with external patio monitoring, external audio with decibel limiting, and singular and dual levels on sea/ocean vessels.
In simplier "plug-in" applications, it is Designated Deejay Entertainment to validate the connection types required to leverage in-house audio
and /or visual systems. Nothing is "assumed".
Its all in the attention to details.