Comparing sound radiation from a loudspeaker with that from a flexible spherical cap on a rigid sphere

It has been suggested by Morse and Ingard that the sound radiation of a loudspeaker in a box is comparable to that of a spherical cap on a rigid sphere. This has been established recently by the present authors, who developed a computation scheme for the forward and inverse calculation of the pressure due to a harmonically excited, flexible cap on a rigid sphere with an axially symmetric velocity distribution. In this paper the comparison is made for other quantities relevant to audio engineers, namely, the baffle-step response, sound power and directivity, and the acoustic center of a radiator.