Horn's directivity related to the pressure distribution at their mouth: part I
Today’s studies about horns are actually based almost completely upon directivity control. In fact, while a good power response is finally recognized so important in professional loudspeaker systems engineering, the directivity behaviour of horns represents certainly a useful tool to get it.
The directional properties of these devices are governed by the wavefront’s shape presented at the mouth. An analisys of the sound pressure’s magnitude and phase distribution across the horn’s mouth could certainly be helpful to understand how the wavefront is shaped there.
Moreover, this could help to understand what happen in some particular circumstances. For example midrange beaming or high frequency mouth diffraction phenomena are two well known obstacles to overcome designing a broad band constant directivity horn. A method forwarded by us to perform such analisys will be shown through graphic illustrations. Presented will be even the results obtained performing measurements upon real devices and the correlation to the polar plots.

Horn's directivity related to the pressure distribution at their mouth: part II
The directional properties of horn devices are governed by the wavefront’s shape presented at the mouth. An analisys of the sound pressure distribution across the horn’s mouth that we call Pressure Distribution Mapping could certainly be helpful to understand how the wavefront is shaped there.
Moreover, this could help to understand what happen in some particular circumstances. For example midrange beaming or high frequency mouth diffraction phenomena are two well known obstacles to overcome designing a broad band constant directivity horn. The method forwarded by us in the previous work is here extended to some different cases and improved in the data processing. The results that come out of such analisys will be shown through graphic illustrations.
Presented will be the results obtained performing measurements upon real devices correlated to traditional directivity plots as well.

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