A ribbon tweeter is a type of speaker, designed to convert audio signals to sound, specifically, high frequency sounds. Most high quality speaker systems have four separate speaker types, tweeters, mid-ranges, woofers, and subwoofers. Each is responsible for generating sounds within a specific range of sounds, tweeters being highest and subwoofers being lowest. These ranges often overlap somewhat. A ribbon tweeter is a type of tweeter that consists of a very thin film, or ribbon of magnetically sensitive material that when energized by an audio signal, converts that signal to sound.
Most speakers employ a design that includes a cone of paper or other flexible material attached to a magnet. The cone vibrates when the speaker is supplied with audio signal, and the vibrations convert the signal to sound. Tweeters are often designed and constructed differently to better translate audio signals into higher frequency sounds.
Ribbon tweeters are one such design and are popular because they provide very high fidelity sound with low distortion. They are also able to project their sound longer distances than many other types of tweeter. A ribbon tweeter also has an inherent directionality to the way it projects sound. These tweeters project sound in one plane very well, a feature which allows the speakers using them to focus sound in a particular way, depending on the way in which they are arranged, especially when combined in series.
Like other more conventional speakers, ribbon tweeters use magnets in their design, but employ them in a different fashion. Two large magnets, usually neodymium magnets, are positioned so as to create a magnetic field between them in which the ribbon is suspended. The ribbon is usually a very thin piece of aluminum, mylar, or plastic with a thin film of metal bonded to its surface. Some manufacturers use proprietary materials for their products. The flexibility of the ribbon allows for very accurate reproduction of high frequency sounds, all the way to the upper limit of human hearing.
Until recently, a typical ribbon tweeter was not able to provide high output, or very loud sounds. For this reason, they were usually only found in home audio systems and rarely used in more large scale applications like arenas, theaters, and public address systems. Recent advancements employing improved design and taking advantage of the unique directional sound projection qualities of this type of tweeter have resulted in more large scale systems employing them, usually combined in arrays with the tweeters aligned in one direction to enhance their ability to deliver quality sound at a distance.