Abstract: Electronic outdoor warning siren systems which include a plurality of speakers arranged in one or more vertically spaced circular arrays of circumferentially spaced vertically oriented speakers to achieve substantially uniform coverage in all radial directions in a horizontal plane, and utilizing frequency variations in adjacent speakers in a given horizontal plane to minimize interference between sound signals from adjacent speakers thereby permitting closer spacing of speakers than would otherwise be feasible and providing uniform omni-directional sound propagation. The same frequency variations are also employed with a plurality of speakers oriented in the same direction and rotated through 360.degree. to accomplish the same result of minimal interference and more uniform sound propagation.