Lecture
This lecture covers the principles of acoustic radiation from combined sources, focusing on the transition between piston speed field and radiation, the distribution of sound intensity, radiation impedance, and the directivity of two-source systems. It explains the relationship between source spacing and wavelength, the behavior of dipoles in near and far fields, and the impact of walls on source radiation. The lecture also discusses the efficiency of radiation from vibrating surfaces and the use of enclosures to improve radiation.