• Question: How do speakers work

    Asked by ferrarimad to Asif, Laura, Lena, Sean, Viv on 14 Mar 2012.
    • Photo: Laura Waters

      Laura Waters answered on 14 Mar 2012:


      Inside your speaker is a magnet that turns electricity into sound which I think is very clever! This causes a vibration that is amplified using a cone so it is loud enough to hear.

    • Photo: Sean Murphy

      Sean Murphy answered on 14 Mar 2012:


      A speaker is essentially an air pump driven by electrical signals.

      In order to translate an electrical signal into an audible sound, speakers contain an electromagnet: a metal coil which creates a magnetic field when an electric current flows through it. This coil behaves much like a normal (permanent) magnet, with one particularly handy property: reversing the direction of the current in the coil flips the poles of the magnet. As pulses of electricity pass through the coil of the electromagnet, the direction of its magnetic field is rapidly changed. This means that it is in turn attracted to and repelled from the permanent magnet, vibrating back and forth.The electromagnet is attached to a cone made of a flexible material such as paper or plastic which amplifies these vibrations, pumping sound waves into the surrounding air and towards your ears.

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