Scientists test the latest radio speaker in an echo free chamber, London.
Radio speaker is tested in specially designed echo free room in London.
C/U Panning round wall show echo absorbing device. M/S two men walking int room with radio set. M/S One man puts set on stool and another one plugs in. C/U Plug going in C/U Man turns on set. M/S man putting microphone into position C/U Hand taking cap off mike. M/S Man leaves room and starts to shut door. C/U Door shutting.
M/S Man on outside battening down door. M/S Man signalling colleague. M/S Man at set puts on earphones etc., M/S First man winding handle. C/U Radio set inside room turning. C/U Turning mechanism. M/S Set passing mike M/S Man outside tuning set. C/U Speaker showing movement of sound waves. MS. Radio set turning. MS. Engineer at controls of set outside. CU. Radio waves. MS. Radio inside room.