Abstract: A compact ceiling mounted loudspeaker system comprising a truncated pyramidal shaped housing supporting an array of four coaxial 2-way loudspeakers. Each loudspeaker is mounted on a respective face of the pyramidal housing so that none faces directly downward. The angles at which the loudspeakers are mounted with respect to the vertical axis and with respect to one another enables the array to produce a flat frequency response hemispherically into the space below the ceiling, with good sound dispersion therein, and with minimal phase cancellation and diffraction effects among said loudspeakers. The speaker system is arranged to be disposed on the grid of a conventional suspended ceiling system to create a space between the suspended ceiling and the surface from which the suspended ceiling is hung to create an infinite baffle to augment the sound produced by the speaker system.