Spherical sound source comprising two coaxial loudspeakers and two mid-high frequency compression drivers. Low frequencies are radiated by the two low-frequency sections of the coaxial loudspeakers. Mid-frequencies 500 Hz-2000 Hz are radiated by the two mid-high frequency compression drivers. High-frequencies 2 kHz-10 kHz are radiated in the horizontal plane by the same mid-high frequency arrangement together with two compression drivers of the coaxial loudspeakers in each vertical direction. Identical drivers form three pairs. One driver from each pair is enclosed in one of two symmetrically opposite half-embodiments, spaced at predetermined distance to create a common radially expanding horn for the two mid-high frequency compression drivers. All loudspeakers share the same vertical axis of rotational symmetry. The two half-embodiments might be used as separate standalone spherically radiating sources when installed on hard surface. The invention is appropriate for sine-swept acoustic measurements and sound isolation measurements in high sound transmission class buildings.