Listed below are some links that help describe what we will talking about on Wednesday July 6

The first article is

Measuring Electricity

Other links below may help give a bit more information.

Electricity: http://science.howstuffworks.com/electricity5.htm

Speakers: http://electronics.howstuffworks.com/speaker.htm

Types of microphones: http://electronics.howstuffworks.com/search.php?terms=microphones

Amplifier Overview http://www.howstuffworks.com/amplifier.htm