Mass Notification Coverage Calculator

Calculate mass notification system speaker/display coverage area per NFPA 72 Chapter 24.

Input Parameters

Results

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Speakers Required
units
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Coverage per Speaker
sq ft
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dB at Coverage Edge
dBA
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SNR Margin
dB
Note: NFPA 72 Chapter 24 requires mass notification systems to produce sound levels at least 15 dB above ambient. Wide-area MNS must cover all occupiable areas with intelligible voice messages.

Reference

Coverage Area = pi x r^2 Speakers Required = Floor Area / (Coverage Area x 0.85 overlap factor) SPL at edge = SPL_ref - 20 x log10(distance / ref_distance) NFPA 72 Ch. 24: Mass notification must be 15 dB above ambient noise level Inverse square law: -6 dB per doubling of distance