Your site was really slow on Big Sale day. Somehow I was able to place an order.Can I now cancel it?

[ABrock]

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[ABrock]

Howabout just one character

[ABrock]

What is the best answer? This is for

[arone_clarke]

Various types of transducer are used to convert electrical signals to Soundin headphones. http://bit.ly/YsuGvw

1. Moving-coil

A typical moving-coil headphone transducer

The moving coil driver, more commonly referred to as a "dynamic" driver is the most common type used in headphones. The operating principle consists of a stationary magnetic element affixed to the frame of the headphone which sets up a static magnetic field. The magnetic element in headphones is typically composed of ferrite or neodymium. The diaphragm, typically fabricated from lightweight, high stiffness to mass ratio cellulose, polymer, carbon material, or the like, is attached to a coil of wire (voice coil) which is immersed in the static magnetic field of the stationary magnet. The diaphragm is actuated by the attached voice coil, when the varying current of an audio signal is passed through the coil. The alternating magnetic field produced by the current through the coil reacts against the static magnetic field in turn, causing the coil and attached diaphragm to move the air, thus producing sound. Modern moving-coil headphone drivers are derived from microphone capsule technology.

• Electrostatic

Electrostatic loudspeaker diagram

Electrostatic drivers consist of a thin, electrically charged diaphragm, typically a coated PET film membrane, suspended between two perforated metal plates (electrodes). The electrical sound signal is applied to the electrodes creating an electrical field; depending on the polarity of this field, the diaphragm is drawn towards one of the plates. Air is forced through the perforations; combined with a continuously changing electrical signal driving the membrane, a sound wave is generated. Electrostatic headphones are usually more expensive than moving-coil ones, and are comparatively uncommon. In addition, a special amplifier is required to amplify the signal to deflect the membrane, which often requires electrical potentials in the range of 100 to 1000 volts.

Due to the extremely thin and light diaphragm membrane, often only a few micrometers thick, and the complete absence of moving metalwork, the frequency response of electrostatic headphones usually extends well above the audible limit of approximately 20 kHz. The high frequency response means that the low midband distortion level is maintained to the top of the audible frequency band, which is generally not the case with moving coil drivers. Also, the frequency response peakiness regularly seen in the high frequency region with moving coil drivers is absent. Well-designed electrostatic headphones can produce significantly better sound quality than other types.^{[citation needed]}

Electrostatic headphones require a voltage source generating 100 V to over 1 kV, and are on the user's head. They do not need to deliver significant electric current, which limits the electrical hazard to the wearer in case of fault.

Electret

An electret driver functions along the same electromechanical means as an electrostatic driver. However the electret driver has a permanent charge built into it, where electrostatics have the charge applied to the driver by an external generator. Electret and electrostatic headphones are relatively uncommon. Original electrets were also typically cheaper and lower in technical capability and fidelity than electrostatics.Patent applications from 2009-2013 have been approved that show by using different materials,i.e a "Flourinated cyclic olefin electret film", Frequency response chart readings can reach 50Khz at 100db.When these new improved electrets are combined with a traditional dome headphone driver, Headphones can be produced that are recognised by the Japan Audio Society as worthy of joining the Hi Res Audio program.US patents 8,559,660 B2. 7,732,547 B2.7,879,446 B2.7,498,699 B2 .

Orthodynamic

Orthodynamic (also known as Planar Magnetic) headphones use similar technology to electrostatic headphones, with some fundamental differences. They operate similarly to Planar Magnetic Loudspeakers.

An orthodynamic driver consists of a relatively large membrane which contains an embedded wire pattern. This membrane is suspended between two sets of permanent, oppositely aligned, magnets. When current is passed through the wires which are embedded in the membrane, the magnetic field produced by the current reacts with the field caused by the permanent magnets and induces movement in the membrane, producing sound.

Balanced armature

Balanced armature transducer with armature balanced and exerting no force on diaphragm

A balanced armature is a sound transducer design primarily intended to increase the electrical efficiency of the element by eliminating the stress on the diaphragm characteristic of many other magnetic transducer systems. As shown schematically in the first diagram, it consists of a moving magnetic armature that is pivoted so it can move in the field of the permanent magnet. When precisely centered in the magnetic field there is no net force on the armature, hence the term 'balanced.' As illustrated in the second diagram, when there is electric current through the coil, it magnetizes the armature one way or the other, causing it to rotate slightly one way or the other about the pivot thus moving the diaphragm to make sound.

The JH Audio JH16 custom in-ear monitor utilizes 8 balanced armatures in a triple crossover configuration (4 low/2 mid/2 high). Multiple balanced armatures are often used to provide a higher fidelity sound.

The design is not mechanically stable; a slight imbalance makes the armature stick to one pole of the magnet. A fairly stiff restoring force is required to hold the armature in the 'balance' position. Although this reduces its efficiency, this design can still produce more sound from less power than any other^{[clarification needed]}. Popularized in the 1920s as Baldwin Mica Diaphragm radio headphones, balanced armature transducers were refined during World War II for use in military sound powered telephones. Some of these achieved astonishing electro-acoustic conversion efficiencies, in the range of 20% to 40%, for narrow bandwidth voice signals.

Today they are typically used only in in-ear headphones and hearing aids, where their diminutive size is a major advantage. They generally are limited at the extremes of the hearing spectrum (e.g. below 20 Hz and above 16 kHz) and require a better seal than other types of drivers to deliver their full potential. Higher-end models may employ multiple armature drivers, dividing the frequency ranges between them using a passive crossover network. A few combine an armature driver with a small moving-coil driver for increased bass output.

The earliest loudspeakers for radio receivers used balanced armature drivers for their cones.

Thermoacoustic technology