Speaker directivity specifications can be misleadingly marketed without effect on speech intelligibility.

Evidence

However, beware of specmanship. One of the authors has seen a loudspeaker advertised as having a constant directivity of 90° × 60° using a horn whose mouth dimensions were 130 × 130 mm. This gives an Fθmin of 2.4 kHz and 3.4 kHz, respectively. As most human speech energy is between 100 Hz and 5 kHz, this speaker’s directivity is going to have very little influence on the intelligibility of the speech! — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 2508

Categorization

• SHARE: Worth sending to anyone who designs or buys PA/speaker equipment — a concrete example of specs that look good but do almost nothing for speech.