Speakers and Sound: A Primer

Sound, and therefore music, comes from speakers that push and pull air, creating sound waves which eventually reach our ears as voices or music. Speakers are most commonly used in two of the residential electronic subsystems: distributed audio and home theater.

A distributed audio system is typically used to provide background music for setting a mood and includes at least two speakers in each room where the distributed audio system is installed. Each pair of speakers in each room is configured in stereo mode, where one speaker plays audio from the left channel, and the other speaker plays audio from the right channel of the audio recording or music being played. Stereo sound gives depth or dimension to sound. A distributed audio system can serve as small an area as a single room (or zone), or it can include speakers in all rooms in the home as well as outside on a deck or patio.

In a distributed audio system the number and size of speakers used is determined by the size and shape of a room. In some situations where the rooms in a home are very large, or ceilings are very high, more than one pair of speakers may be required in a room to provide adequate stereo sound.

A home theater system uses speakers in a multi-channel configuration to create a surround sound effect. A surround sound processor separates the various components of a sound track, such as that included on movie DVDs. The processor disperses these separate portions of the sound track to different speakers placed around the room. For example, voices may come from behind the video screen, while other sound effects originate beside or even behind the viewer. A surround sound system typically includes three speakers in the front (left, center, right), two speakers at the rear, and optionally two more speakers at the sides of the viewing area. These speakers can be installed in the walls or ceiling, or can be freestanding floor or shelf speakers. Sound quality is critical to making a great home theater system, and thus home theater speakers are typically constructed using different materials and construction techniques than other types of speakers to maximize their performance.