A loudspeaker enclosure for mounting in an aperture in a cavity wall with a part of the enclosure being located within the wall cavity adjacent the aperture, comprises a main enclosure unit for mounting in the aperture and housing one or more loudspeaker drive units, and a supplementary enclosure unit for location within the wall cavity and being acoustically connected in use to the main unit to increase the effective internal volume of the enclosure beyond that of the main unit. The supplementary unit is connected to the main unit by an articulated connection enabling the main unit to be angled relative to the supplementary unit while the supplementary unit is being inserted through the aperture and into the wall cavity, and enabling the main unit to be aligned with and acoustically coupled to the supplementary unit when the main unit is positioned in the wall aperture.