Hotel lobby — background music, 20 × 12 m

Hotel lobby audio is a hospitality decision before it is an audio decision. The brief is the opposite of a concert hall — speech and music must be present but never the subject of attention. The standard target is 70–75 dB at the listener, calibrated against a noise floor of HVAC, fountains, conversation and footfall.

This preset configures the planner for a typical 20 × 12 m lobby with a listener distance of around 6 m from the nearest cabinet, a 50 % power setting on the speaker (BGM headroom, not peak) and a point-source dispersion that suits the open ceiling plane. The cabinet shown — a K-array Lyzard KZ1 — is one of several valid choices; swap to any other point-source in the dropdown to see the SPL and quantity implications.

The output you should read: SPL at listener (target 70 dB, the planner flags ≥ 12 dB headroom as wasteful in this application), coverage half-width on the −6 dB axis (use it to step out the cabinet spacing along the lobby ceiling), and quantity (the planner compares the angle the room's width subtends at a front-centre position against the cabinet's horizontal dispersion and rounds up — no area enters it; a real design will then account for obstructions and zone boundaries).

Note what the calculator deliberately doesn't show: it doesn't model the reverberant field of a hard-floored marble lobby (reverb time will inflate effective SPL by 3–6 dB and demand more directional cabinets), and it doesn't allocate audio to zones (entry foyer vs lounge vs reception desk — usually separate amp channels with separate volume profiles).