Abstract: A loudspeaker is formed integrally with a rectangular ceiling tile which is provided with electrical contacts for connecting the loudspeaker in series or parallel combinations with other loudspeaker-tile assemblies and for supplying power to the loudspeaker from a bus, such as the T-bar which supports the ceiling tile in a typical suspended ceiling installation. A plurality of these loudspeaker-tile assemblies can be used as part of either the ceiling or wall of a large room into which sound is to be transmitted. The loudspeakers are completely concealed from view. Different electrical delay lines can be connected to various speakers in the array of speakers to produce desired acoustical effects.