Removing Iron Filings From Speaker Gaps

Radio Record, Volume VIII, Issue 32, 15 February 1935, Page 45

Removing Iron Filings From Speaker Gaps

Dynamic speakers which produce rasping tones often have iron filings in the air-gap between the pole and the voice coil. The usual method of removing these is to apply compressed air, but in many cases this does not do the job. ' Loosen the screws holding down the diaphragm ring and remove the diaphragm. Take a pipe-cleaner and apply paste on its end. Rub the pasty -end around the pole surface and it will snare all filings. After they are removed take another ‘cleaner and remove the paste. ‘Then apply with a brush or another cleaner, lacquer or bronzing liquid to the pole. This. will give it a smooth coating, pre‘venting the iron filings from clinging te the metal in future, If, at a later date, filings should accumulate despite the lacquer, they can be removed from the protected surface simply by blowing into the gap. ' When finished, it is of course necessary to centre up the voice coil before replacing the diaphragm,