d&b Y8 - Manual (Page 8)

2.4. Dispersion characteristics
The graphs below show the horizontal dispersion angle over
frequency plotted using lines of equal sound pressure (isobars) at
–6 dB and –12 dB. The nominal dispersion is maintained above
600 Hz, while a useful horizontal dispersion control is achieved
down to 500 Hz.
Isobar diagram Y12 horizontal Isobar diagram Y8 horizontal
d&b Y8/Y12 Manual 1.1 en 8