License Info
Image Use
Custom Photos
Site Info
Contact Us

Visit Science,
Optics, & You

The Galleries:

Photo Gallery
Silicon Zoo
Chip Shots
DNA Gallery
Amino Acids
Religion Collection
Cocktail Collection
Screen Savers
Win Wallpaper
Mac Wallpaper
Movie Gallery

How A Speaker Works

Most loud speakers consist of a circular permanent magnet surrounding a freely moving coil, which is attached to a cone shaped diaphragm. In the speaker below, the circular magnet is partially cut away so that our visitors can see how it operates.

Interactive Java Tutorial
Our servers have detected that your web browser does not have the Java Virtual Machine installed or it is not functioning properly. Please install this software in order to view our interactive Java tutorials. You may download the necessary software by clicking on the "Get It Now" button below.


Alternating current, generated by a microphone, a pickup head, amplifier, radio, or another source, flows through the coil of the speaker. You can observe the operation of a microphone at our Condenser Microphone Java Tutorial.

The current, alternating at the same frequency as the sound waves that generated it, induces an alternating magnetic field in the coil. As the polarity of the magnetic field of the coil alternates, it is alternatively attracted to and repelled by the permanent magnet. This causes the coil to vibrate. The vibrating coil causes the attached cone shaped diaphragm to vibrate and reproduce the sounds generated by the original source.


Questions or comments? Send us an email.
© 1995-2015 by Michael W. Davidson and The Florida State University. All Rights Reserved. No images, graphics, software, scripts, or applets may be reproduced or used in any manner without permission from the copyright holders. Use of this website means you agree to all of the Legal Terms and Conditions set forth by the owners.
This website is maintained by our
Graphics & Web Programming Team
in collaboration with Optical Microscopy at the
National High Magnetic Field Laboratory.
Last Modification: Friday, Nov 13, 2015 at 02:19 PM
Access Count Since March 26, 1999: 243716