Carrie Casey of Fox Chapel watched as her grandson, Brooks Murray, climbed to the top of a mountainous wall at McCahill Park. Brooks of Steamboat Springs, Colo., was one of few 4-year-olds to attempt ...
The common type of loudspeaker that uses a magnetic field to move a cone-shaped diaphragm. When alternating current (the audio signal) is applied to the coil, the diaphragm vibrates and causes air to ...