Abstract: A loudspeaker and horn combination having desirable sound clarity characteristics and having a desirable per unit of electric power input to per unit of sound output ratio can be constructed using a horn body of one or more parts of a rigid, closed cell polyurethane foam material having a smooth exterior skin or surface shaped so as to include an internal horn cavity. A speaker is located so that its diaphragm extends across an entrance end of the cavity. The cavity is shaped in a bilaterally symmetrical manner so as to include a sound chamber region adjacent to and leading from the speaker diaphragm, this sound chamber region having a restricted throat located intermediate its ends and having a continuous curvature between its ends, a flare region diverging outwardly from the end of the sound cavity region remote from the speaker and a transitional region located generally between the flare and sound cavity regions so as to connect the adjacent surfaces of these regions.