The design of a loud-speaker

This paper gives an account of an investigation of the requirements for design of a loud-speaker for use in livingrooms. The design which resulted from the investigation is described, and there is also some discussion of the criteria of quality of performance which have been adopted. Essential requirements were that the loud-speaker should be capable of standardization to a design which would be inexpensive for production in quantity; and that the quality of reproduction should be superior to that generally supplied by available commercial instruments¿in fact, that the loudspeaker should be as near to perfection as is economically possible. The question of size was discussed during the investigation when some knowledge of the limitations thereby imposed on the quality of reproduction had been gained, and a compromise was struck between conflicting requirements. The investigation was carried to the point where a specification was issued to interested contractors, and tenders for the manufacture of loud-speakers were invited. Under the terms of this specification, samples were submitted by several contractors, and some of the samples submitted were satisfactory both as to performance and as to price. The development of the design, though fairly complete, does not include experience with the mass-produced article, or with methods of acceptance testing of supplies in bulk.