A Model of Open-Baffle Loudspeakers - DIY Audio Projects
A Model of Open-Baffle Loudspeakers - DIY Audio Projects
A Model of Open-Baffle Loudspeakers - DIY Audio Projects
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2.4 Far-field radiation<br />
2.4.1 Radiation from the driver<br />
As far as the direct sound only is concerned, the driver can be regarded to reside in an infinite, flat<br />
plane. This approximation can be used even with completely free pistons, since the diffracted part is<br />
taken separately into account. There are two ways <strong>of</strong> representing the far-field direct radiation from<br />
a rigid piston: in frequency domain and in time domain. The frequency-domain expression for the<br />
sound pressure created by a piston vibrating with a volume velocity q and a frequencyfat distance r<br />
and angle 8 can be represented by the familiar expression6<br />
zypq 2 J1 (ka sin 0)<br />
Equation 11 p = --<br />
r kasine<br />
and the time-domain radiation corresponding to a step displacement A by the following<br />
equationy:<br />
Equation 12 p =<br />
r-ct<br />
a2 sin2 8 - (r - ct)2<br />
ct