The design and characteristics of dynamic loudspeakers (speakers)
We will consider the design and characteristics of the model dynamic loudspeaker (speaker).
External dimensions - usually from 5 to 30 cm in the transfer to the diameter of the diffuser, the weight corresponds to the size.
Diffuser - this thing plays the sound. The material of the diffuser is often pressed paper (cellulose) impregnated mass consumption models. The main thing - to the diffuser is not subjected to deformation during operation. For models designed to work in cars, often use foam plastic as a material is not hygroscopic and has sufficient the stiffness. For more expensive models, the choice of material of the diffuser wider, and mostly depends on the "steepness" of the developer. In Vogue the manufacture of the diffuser is made of aluminum, are often used combined materials (sandwich).
Convolute - diffuser through it attached to the frame body (DiffuseMaterial). Can be molded together with the diffuser in the process of forming, and can be manufactured separately from other material - latex ,polyurethane foam. Most importantly - have to provide minimum resistance to movement of the diffuser during operation. Often convolute paper impregnated with special compounds for greater flexibility and at the same time parasitic damping resonant vibrations. Usually bumps bonded to DiffuseMaterial, but met before construction to mount the pressure ring.
Magnetic system - creates the magnetic field in which the coil moves. Obviously, the stronger this field, the louder "yelling" speaker, so the designers strive use a high-performance magnetic materials. Shocks, self-disassembly of the magnetic system, high temperature - the characteristics can irreversibly deteriorate. Sometimes the magnetic top system escaped (for example, for speakers, built-in TVs and the monitors). Used to date the construction and to enhance the magnetic field of the magnetic system is wound on an additional coil, powered by auxiliary supply.
Kern - transmits a magnetic field inside the coil, but not intended to be magnetized, therefore, is made made of magnetic material.
The coil form the carrier coils are made of thin, durable material, not shielding magnetic field and having a minimum weight. In older designs - exclusively the cardboard, in new - aluminum.
Voice coil - to her and supplied power delivered by the amplifier. Active resistance coil (DC):
from 2 Ohms (for car speakers);
4 - 6 - 8 Ohms (most common);
16 - 32 Ohm (for economic or special purposes).
Coil often is wound in two layers conventional wire in the varnish insulation, but in particularly powerful wire designs may be of rectangular section is to increase the effective fill the gap. The coil is glued to the frame. Poor sizing, or overload the dynamics of the portion of the turns can "hang out" inside and create sound effects that are not related to the category of high quality sound reproduction. In the last century Amateurs independently rewinding voice coils, especially the design many of the speakers is allowed.
Centering washer - appointment it is clear from the title. The main thing - do not interfere with the movement of sound of the coil, and to be breathable, otherwise inside the magnetic system,where there is a coil forms a closed volume. But about its dangers we remember further, when we consider acoustic design the loudspeakers. Washer material - something like impregnated gauze for consumer goods, and anything exclusive.
Because of high humidity or other bad influences can disrupt the alignment, defect exists without disassembly the dynamics. To check the alignment,carefully pressing on the diffuser and listening to the sounds inside - they should not be!
Conclusions coil - run spectrophotome "tinsel" from the mixed thin copper and silk threads. Conclusions should not interfere with the movement of the diffuser. Because of the constant movements have a tendency to dropped near the contact Pyatakov where are soldered to the terminals of the voice coil. A good alternative is wire MGTF with the removed insulation. Too long conclusions can RUB against diffuser and create interesting sounds, giving a unique flavor sounding speakers, but do not appreciate other listeners.
Gap - the gap between the magnetic system and core, which moves the voice coil. The smaller the gap, the higher the inductance, the higher the efficiency of the speaker.
Numerous attempts were made to increase the inductance without increasing the gap by introducing a magnetic back the fluid. But this led to an increase in the resistance to movement diffuser and increase the lower boundary frequency. Getting into clearance of debris is fraught with distortion, so usually close the gap cap (figure not available). At the same time the cap improves playback upper audio frequencies.
Frame - a frame, it DiffuseMaterial. Cheap designs - from plastics, consumer goods - from stamped sheet, the more expensive designs - casting aluminum alloys. Usually present in the frame of the window for free the movement of air, but under high-frequency dynamics is not required. The frame must be very hard, not to resonate, to be comfortable when install the speaker into the housing and to please the eye happy owner device.
About the characteristics that directly affect the sound will cover in the next article.
We reviewed General issues of design speakers now look at some exotic designs.
The shape of the cone is a circle, as the most innovative element.
Elliptical - only to reduce dimensions, and do not have any advantages. And the Japanese were honored to do even square, which fits very nicely in a rectangular case. The material of the diffuser is the thinnest slice of birch, aged in sake*****. True gourmets will certainly appreciate this device.
NASA (USA) to test re-entry vehicles "Gemini" speaker built more than a meter in diameter with MECHANICAL DRIVE. He was subsequently transferred to the disco in Atlanta. The sound of this monster was shaken to the core in words.
For high-performance loudspeakers (tweeters) diffuser as the concept is virtually absent, the sound is played spherical the cap is glued to the coil. To reduce the weight of the cap is made from silk, sometimes from beryllium, applied ceramic or even diamond spraying with the aim of obtaining clear as a diamond, sound.
Very limited quantities available ELECTROSTATIC emitters of sound that cannot be called speakers. In them the role of the diffuser performs thin film sputtered with foil, and it is all Packed into a giant capacitor, polarizable voltage of 1000 Volts. This design does not require special acoustic design and excellent sound at frequencies above 100 Hz.
We have produced in the country ISODYNAMIC the emitters is also a film with a deposited conductors, but it is between the two multi-pole magnets. Perfect emitter frequencies above 5 kHz.
Piezoceramic transducers and speakers-exotic common (see boomboxes with two-three-band emitters). My the cat had not heard a single system, applying for Hi-Fi sound reproduction . All of them can be classified as Hi-Hi.
And the most exotic emitter - Ionian. Exhibited at the national exhibition of creativity hams somewhere in the 50-ies of the last century. The flow of air ions was modulated within sound frequency. The sound quality is beyond praise. Disadvantages - large dimensions and harmful air ionization. Looks like a foreign country trying times to revive such emitters, but in the series they will not go - normal speakers much easier and cheaper , and to capture the difference in the sound you need trained ears. About the complex exercise for the ears, planned special article.
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