Loudspeaker "Hiss"

Radio Record, Volume III, Issue 16, 1 November 1929, Page 30

Loudspeaker "Hiss"

How to Cure It BROADCAST listeners sometimes complain that there is a sort of hissing or "buzzing" noise continuously audible from their loudspeaker when a programme is coming through, ° This is distinct from the harsh sound due to overloading of the loudspeaker, which can be readily detec ed owing to its greater prominence when the volume of sound transmitted is increased. The hissing noise, on the other hand, remains practically constint whatever is coming through from the broadeasting station. A cure may be effected by the provision of a shunting condenser across the terminals of the loudspeaker. For genera. use this condenser may have a value of .002 mircrofarads. Those who are critical of quality and who like to hear every transmission. at its best will be well advised to use different values of shunting capacity for different items in the programmes. Yor example, the value quoted above ‘will usually suit for speech, but for a full orchestra a larger condenser, even up to a value of about .02, will usually help to give éléarer reproduction and to enable the various instruments to be distinguished. Too large a condenser is to be avoided, or the higher notes will be partially lost,~and the general effect spoiled.