Directivity of a two-source system
Directivity term is expressed by writing
and
and assimilates pair of sources to a single one centered in the middle ("far field" approximation ). It is written:
( if
)
Remarque : Remark
This equation shows that directivity depends
on the ratio between source spacing d and the wavelength (
).on the amplitude and the relative phase of two sources,
and
being complex numbers that represents amplitude and phase differences
The dependence of term
on terms
and
allows to choose the directivity (and frequency response) for particular applications.
