A mid-range speaker is a

loudspeaker A loudspeaker (commonly referred to as a speaker or speaker driver) is an electroacoustic transducer that converts an electrical audio signal into a corresponding sound. A ''speaker system'', also often simply referred to as a "speaker" or " ...

driver that reproduces sound in the frequency range from 250 to 2000 Hz. It is also known as a squawker. 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

woofer A woofer or bass speaker is a technical term for a loudspeaker driver designed to produce low frequency sounds, typically from 50 Hz up to 1000 Hz. The name is from the onomatopoeic English word for a dog's bark, " woof" (in contrast to th ...

s. 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, rags, grasses or other vegetable sources in water, draining the water through fine mesh leaving the fibre evenly distributed ...

, occasionally impregnated and/or surface-treated with

polymer A polymer (; Greek '' poly-'', "many" + ''-mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic a ...

s or

resin In polymer chemistry and materials science, resin is a solid or highly viscous substance of plant or synthetic origin that is typically convertible into polymers. Resins are usually mixtures of organic compounds. This article focuses on natu ...

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 propylene. Polypropylene belongs to the group of polyolefins and ...

, 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 a ...

, 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 compo ...

, or light metal

alloy An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductility, ...

s based on

aluminium Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. I ...

magnesium Magnesium is a chemical element with the 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 of the periodic ta ...

titanium Titanium is a chemical element with the 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 is a live music performance in front of an audience. The performance may be by a single musician, sometimes then called a recital, or by a musical ensemble, such as an orchestra, choir, or band. Concerts are held in a wide variety a ...

mid-range drivers are

compression driver A compression driver is a small specialized diaphragm loudspeaker which generates the sound in a horn loudspeaker. It is attached to an acoustic horn, a widening duct which serves to radiate the sound efficiently into the air. It works in a "co ...

s coupled to

horns Horns or The Horns may refer to: * Plural of Horn (instrument), a group of musical instruments all with a horn-shaped bells * The Horns (Colorado), a summit on Cheyenne Mountain * ''Horns'' (novel), a dark fantasy novel written in 2010 by Joe Hill ...

. A very few mid-ranges are

electrostatic Electrostatics is a branch of physics that studies electric charges at rest (static electricity). Since classical times, it has been known that some materials, such as amber, attract lightweight particles after rubbing. The Greek word for amber ...

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 Fundamental may refer to: * Foundation of reality * Fundamental frequency, as in music or phonetics, often referred to as simply a "fundamental" * Fundamentalism, the belief in, and usually the strict adherence to, the simple or "fundamental" idea ...

s emitted by musical instruments and, most importantly, the human voice, lie. This region contains most sounds which 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 the television, TV, TV set, telly, tele, or tube, is a device that combines a tuner, display, and loudspeakers, for the purpose of viewing and hearing television broadcasts, or using ...

s and small radios have only a single mid-range driver, or two for stereo sound. Since, in the case of television the most important aspect is the talking, 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 (

s) and the high frequency drivers (

tweeter A tweeter or treble speaker is a special type of loudspeaker (usually dome, inverse dome or horn-type) that is designed to produce high audio frequencies, typically deliver high frequencies up to 100 kHz. The name is derived from the high ...

s). 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 enclosures all controlled by a mixing console that makes live or pre-recorded sounds louder and may also distribute those sounds ...

s. Placement of the mid-range (and tweeter) drivers on the enclosure baffle significantly affects 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

, 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