Strutt|Input Data|Empirical|Typical PA Loudspeaker Directivity inserts the typical directivity index (in dB) of an outdoor-type PA system (e.g. for an industrial plant) into the current row of the worksheet.
Strutt implements the directivity as a function of angle by interpolating in Table 8.13 of Laymon Miller
Reference: Laymon Miller Noise Control for Buildings and Manufacturing Plants, p8-13