Do those tall skinny speakers work differently than regular speakers?
Most ordinary speakers use an electromagnet to push and pull on a cone-shaped diaphragm (see How Speakers Work for details). But there are a few other technologies on the market. The speakers you saw at your friend’s house are probably electrostatic speakers. Instead of using an electromagnet, electrostatic speakers vibrate air using a large, thin, conductive diaphragm panel suspended between two stationary conductive panels. These conductive panels are charged with electrical current from a wall outlet, creating an electrical field with a positive end and a negative end. The audio signal runs a current through the suspended diaphragm panel, rapidly switching between a positive charge and a negative charge. When the charge is positive, the panel is drawn toward the negative end of the field; when the charge is negative, it moves toward the positive end of the field. In this way, the diaphragm rapidly vi
