Horn Loudspeaker Range

Range (ft) = 3.28084 × 10^((sensitivity + 10 log₁₀(power) − ambient − margin − loss) / 20)

Free-field, on-axis estimate. Sensitivity must be rated at 1 W / 1 m. Weather, obstructions, frequency response and directivity change real coverage. This does not establish speech intelligibility or emergency notification compliance.