In Part I of this monograph a description is given of the design and performance of a compact two-unit loudspeaker orginally intended for use in mobile control room. Part II describes investigations to determine why the reproduction given by the latest hanging studio loudspeaker type LS5/6 became noticeably coloured when it was suspended above the picture monitors in a television sound-control room, as dictated by considerations of layout. It is concluded that the colouration was due to the build-up of multiple reflections from the walls and windows when the loudspeaker was suspended symmetercially in the corner of the control room and that the colouration was more noticeable in the case of the LS5/6 primarily because of the higher quality of this loudspeaker.