Directivity and elevated placement produce even coverage across most of a deep audience.

Evidence

Two constant-directivity horn speakers 7.5 m above ear height with more power to the horn covering the back Table 7.7 shows the results of doing this. Now the sound is more even within ± 0.15 dB from 5 m to 19 m in the audience. It drops at the front and the back, and the maximum variation is 10.8 dB. In practice, the front row is likely to receive additional sound from the stage, thus boosting its level. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2544