A mid-range speaker is a

loudspeaker A loudspeaker (commonly referred to as a speaker or, more fully, a speaker system) is a combination of one or more speaker drivers, an enclosure, and electrical connections (possibly including a crossover network). The speaker driver is an ...

driver that reproduces sound in the frequency range from 200 to 2,000 Hz. Mid-range drivers are usually cone types or, less commonly, dome types, or compression horn drivers. The radiating diaphragm of a cone mid-range unit is a truncated cone, with a voice coil attached at the neck, along with the spider portion of the suspension, and with the cone surround at the wide end. Cone mid-range drivers typically resemble small woofers. The most common material used for mid-range cones is

paper Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, Textile, rags, poaceae, grasses, Feces#Other uses, herbivore dung, or other vegetable sources in water. Once the water is dra ...

, occasionally impregnated and/or surface-treated with

polymer A polymer () is a chemical substance, substance or material that consists of very large molecules, or macromolecules, that are constituted by many repeat unit, repeating subunits derived from one or more species of monomers. Due to their br ...

s or

resin A resin is a solid or highly viscous liquid that can be converted into a polymer. Resins may be biological or synthetic in origin, but are typically harvested from plants. Resins are mixtures of organic compounds, predominantly terpenes. Commo ...

s in order to improve vibrational damping. Other mid-range cone materials include plastics such as

polypropylene Polypropylene (PP), also known as polypropene, is a thermoplastic polymer used in a wide variety of applications. It is produced via chain-growth polymerization from the monomer Propene, propylene. Polypropylene belongs to the group of polyolefin ...

, Cobex, Bextrene, woven

Kevlar Kevlar (para-aramid) is a strong, heat-resistant synthetic fiber, related to other aramids such as Nomex and Technora. Developed by Stephanie Kwolek at DuPont in 1965, the high-strength material was first used commercially in the early 1970s as ...

, fiberglass,

carbon fiber Carbon fiber-reinforced polymers (American English), carbon-fibre-reinforced polymers ( Commonwealth English), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon comp ...

, or light metal

alloy An alloy is a mixture of chemical elements of which in most cases at least one is a metal, metallic element, although it is also sometimes used for mixtures of elements; herein only metallic alloys are described. Metallic alloys often have prop ...

s based on

aluminium Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...

magnesium Magnesium is a chemical element; it has Symbol (chemistry), symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 ...

titanium Titanium is a chemical element; it has symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resistant to corrosion in ...

, or other alloys. The radiating surface of a dome mid-range is typically a 90-degree section of a sphere, made from cloth, metal, or plastic film, with its suspension and voice coil co-located at the outer edge of the dome. Most professional

concert A concert, often known informally as a gig or show, is a live performance of music in front of an audience. The performance may be carried by a single musician, in which case it is sometimes called a recital, or by a musical ensemble such as an ...

mid-range drivers are compression drivers coupled to horns. A very few mid-ranges are electrostatic drivers, planar magnetic drivers, or ribbon drivers. A mid-range driver is called upon to handle the most significant part of the audible sound spectrum, the region where the most fundamental frequencies are emitted by musical instruments, and, most importantly, the human voice, lie. This region contains most sounds that are the most familiar to the human ear, and where discrepancies from faithful reproduction are most easily observed. It is therefore paramount that a mid-range driver of good quality be capable of low-distortion reproduction. Most

television set A television set or television receiver (more commonly called TV, TV set, television, telly, or tele) is an electronic device for viewing and hearing television broadcasts, or as a computer monitor. It combines a tuner, display, and loudspeake ...

s and small radios, especially AM receivers, have only a single mid-range driver, or two for stereo sound. With human speech being the most important aspect of television audio and AM radio, it works out well. Since the ear is most sensitive to the middle frequencies produced by a mid-range the driver and amplifier can both be low power, while still delivering what is perceived to be good sound both in terms of volume and quality.

Installation issues

Mid-range drivers are usually used in three-way multi-driver speaker systems. There are therefore special considerations involved in the acoustic join between the mid-range and both the low frequency ( woofers) and the high frequency drivers ( tweeters). The nature of the drivers on both sides of the mid-range, and the mid-range itself affect the selection of crossover frequency and slope. Nearly all crossovers are passive circuits, designed to match the characteristics of the drivers and their mounting, and are built of capacitors, inductors, and resistors. Active or 'electronic' crossovers are used in some high performance hi-fi speakers, and in professional

sound reinforcement system A sound reinforcement system is the combination of microphones, signal processors, amplifiers, and loudspeakers in Loudspeaker enclosure, enclosures all controlled by a mixing console that makes live or pre-recorded sounds louder and may also ...

s. Placement of the mid-range (and tweeter) drivers on the enclosure baffle significantly affect the output of the driver, and the material surrounding the mid-range and tweeter drivers on the baffle can produce (or inhibit) reflections of energy from the baffle face, or other items, further influencing the output. Grilles, especially those with structural frames, can further modify the output of the entire speaker system. One of the terms used in design circles to describe some of these diffraction and reflection artifacts is the ''baffle step'' effect. When a mid-range speaker is mounted in the same box as a woofer, it will have its own small sub-enclosure, or a sealed back, to prevent the woofer's backwave radiation into the box from affecting the mid-range's cone or dome motion.

References

{{reflist Loudspeakers

Installation issues

See also

References