Abstract: A loudspeaker system in which two loudspeakers that cover different but overlapping frequency ranges, for example a treble range and a bass range, are mounted to radiate from co-planar mouths. Phase delay which is introduced by the radiator for the lower range is compensated by an acoustic delay which is disposed between the radiator of higher optimal frequency range and its mouth. This acoustic delay preferably takes the form of an exponential horn which introduces a delay corresponding to the displacement, from the common plane of the mouths, of the effective source of signals radiated by the lower frequency radiator at the crossover frequency in the overlapping region.