One embodiment provides an omnidirectional loudspeaker comprising a first axisymmetric reflector, a second axisymmetric reflector, a sound source in the first axisymmetric reflector or the second axisymmetric reflector, and a horn including a straight section and a growth section extending from a distal end of the straight section. The growth section comprises one or more curves that are scaled with a radial coordinate and that expands sound waves generated by the sound source.