Abstract: A loudspeaker is disclosed in which the frustoconical diaphragm is formed in two parts, including a first or outer part made of synthetic material e.g. polypropylene or polystyrene, and a second or inner part of paper or plastic material having higher heat resistance than the first part. The second part is therefore able to withstand the high temperatures of the moving coil support to which it is attached while affording advantages of synthetic material diaphragms.