Abstract: A loudspeaker apparatus comprises an enclosure having a loudspeaker mounted on a surface thereof, means within the enclosure and cooperating with other surfaces thereof for initially directing sound energy emanating from the back of the loudspeaker through a first sound wave compression zone in a first direction and then substantially equally into each of two second sound wave compression zones in respective second directions opposed to the first direction, and means in each of the second compression zones for propagating the sound energy received thereby out of the enclosure, the propagating means either comprising a passive radiator mounted on a corresponding enclosure surface partially defining each of the second compression zones or comprising ports which face in a direction parallel to that in which the loudspeaker faces and which place each second compression zone into open communication with the outside of the enclosure.