 that the listener should be able to imagine himself to be in the presence of the original source of sound.There is, of course, scope for legitimate experiment in the processing of the reproduced signals in an endeavour to improve on nature, however, realism, or as near an approach to it as may be possible, ought surely to be regarded as the normal condition and avoidable departures from this state, while justified upon occasion, should not be allowed to become a permanent feature of the system.In designing a loudspeaker, the BBC established the compromise that had to be established between size, weight and cost considerations.