Changzhou Su Yang Electronics Co., Ltd.
Address: Changzhou City, the western suburbs of Benniu Town Road No. 30 Taurus
Phone: 133824846598
Fax: 0519-83211109
Official website: www.suyangdz.cn
The speaker is a kind of electrical signal into sound signals of electro acoustic devices. Exactly speaking, speaker is actually a range of audio frequency electric power signal by can change (electric energy, mechanical energy, sound energy) into distortion is small and has enough sound pressure level of audible sound.
There are many types of speakers, the classification method is also varied, generally according to its working principle, the shape of the diaphragm and the frequency range of the frequency range.
1、 the structure of the speaker
Our most common speakers for electric cone paper. Electric cone speaker that in the past, we often say the speaker cone, although now diaphragm still to paper basin mainly, but at the same time, there many vibration membrane of polymer materials, metal diaphragm, with cone loudspeaker calling worthy. The conical paper bowl speakers generally consist of three parts:
1、The magnetic loop system (permanent magnet, magnet, column, U, T, magnetic iron or iron plate, Hua Si).
2、Vibration system (vibrating plate, sound, film, sound).
3、The auxiliary supporting system (damper frame, elastic wave, < > pads, terminal board).
For the above three systems in detail:
1、Voice coil, voice coil is tapered paper cone loudspeaker drive unit, it is very fine copper wire (copper / aluminum) divided into two layers (four layers) around the bone with (paper tube / aluminum / film, etc.), generally around a few laps, placed in the magnetic core and the guide magnetic plate constitutes a magnetic suspected gap. The voice coil is fixed with the paper bowl. When the sound current signal is connected to the voice coil, the vibration of the voice coil is driven by the vibration of the paper.
2、Paper basin (drum paper): cone shaped paper bowl speakers of the conical diaphragm used in many types of materials, there are generally two types of natural and man-made fibers. Natural fiber cotton, wood, often using wool, silk, rayon, nylon, rayon just using glass fiber etc.. Because the paper basin is a speaker of the sound radiation device, in a large extent determines the speaker's voice performance, so no matter what kind of paper bowl, the requirements of both light and rigid, can not be due to environmental temperature, humidity changes and deformation.
3、Edge flange: folding ring is to ensure that the paper basin along the speaker of the axial movement, limit horizontal movement and set up, and at the same time to stop the paper before and after the air dare to flow. The material of the folding ring is used for the material of the common paper basin. It is also used in plastic, natural rubber and so on.
Formed by the hanging side and elastic wave of rigid or compliant mobile speed of the cone, the horn all flexible, elastic wave provides about 80%, suspension side to provide about 20%, there are two functions of suspension side, its original work is to keep the voice coil on the center pole gap however, for the
mode of vibration cone edge, damping effect caused by the suspension side is very important, choose drama hanging edge thickness and material to change the reaction of cone horn, distortion of damping and preventing back cone rear sonic reflection can change with the distorted model in the amplitude and phase of the cone, makes it a complete element and can implement response tools.
4, damper (Dan Bo): o.d.meter tablets for the binding site support voice coil and cone, the vertical and not skew. Centering support chip has many concentric rings, the voice coil in the magnetic gap freely on the move without lateral movement, to ensure sound does not ring and the guide magnetic plates collide. Centering support chip dust cover is to prevent external dust fall in the magnetic gap, to avoid dust and voice coil friction, and the speaker occurrence of abnormal sounds. < br / > (centering support chip) elastic wave has some features. The second function is keep the voice coil centered in the gap, also put forward to apply for a avoid external layer of ash particles penetrated inside the gap. At the beginning of the elastic wave is to provide the horn monomer of restoring force. However, elastic wave of hardness and impact horn resonance (FO), the loudspeaker resonance is supple and quality function.
(4)Bracket
(2) Diaphragm
(7) Magnetic field
(3) Suspension
(8) Back mixing hole
(5) Permanent magnet
(6) Magnetic circuit
(1)Voice coil
Positive voice coil force +fD
(9) The front cover
(10) Dust cover
(11) Mixing paper
2、Speaker classification
According to the principle of work: according to the work principle of different speakers are mainly divided into electric speakers, electromagnetic speakers, electrostatic speakers and piezoelectric speakers, etc..
1、Electric speaker: the speaker uses a power conductor to make a sound circle, and when an audio current signal is entered in the voice coil, the voice coil is equivalent to a current carrying conductor. If it is placed in a fixed magnetic field, according to the principle of the action of the current carrying conductor in a magnetic field, the voice coil is proportional to the frequency of the audio frequency and the direction changes with the audio current. In this way, the voice coil will vibrate in the magnetic field, and drive the vibration of the diaphragm, and the air around the diaphragm is also vibrating, so that the electrical signal is converted into sound waves. This speaker is the most widely used.2、Electromagnetic loudspeaker: also called reed loudspeaker, the sound source signal current through the voice coil will put soft material made of reed magnetized and magnetized can vibration reed and magnet mutual attraction or rejection, generating a driving force, so that the vibration of the vibrating diaphragm and pronunciation.
3, electrostatic speaker: this speaker is the use of the principle of capacitance, the electric diaphragm and fixed electrode in the opposite polarity configuration, forming a capacitor. The sound source signal is applied to the poles of the capacitor, and the electric field intensity is changed to produce the attraction, which drives the vibration of the diaphragm.
4、Piezoelectric speaker: the use of piezoelectric material by the electric field role in the occurrence of deformation of the principle, the piezoelectric element placed in the electric field of the audio current signal, so that the occurrence of displacement, and thus produce a reverse voltage effect, and finally drive the diaphragm sound.
according to the shape of the film shape: the main speakers have a cone, Hira Igata, ball shaped, ribbon shaped, thin, etc..
1、The most widely used in the conical diaphragm loudspeaker is the conical paper bowl loudspeaker, which is the most common and widely used speaker in the electric loudspeaker, especially the application of the low.
2, flat panel speaker: it is also a kind of electric loudspeaker, its vibrating film is flat, and the whole vibration directly radiate sound wave.
its plane vibration film is a round peak of the nest plate, the plate is made of aluminum foil with the peak nest core, two sides covered with glass fiber. Its frequency characteristic is relatively flat, bandwidth and distortion is small, but the rated power is small.
3, ball top - shaped Speaker: the ball top - shaped speaker is one of the electric speakers, and the working principle is the same as the paper bowl. The salient features of the spherical dome shaped speaker are good transient response, low distortion, good directivity, and low efficiency, which are used as the medium and high - high unit of the speaker system.
4, horn speaker: working principle and electric horn loudspeaker cone loudspeakers same. Diaphragm horn loudspeaker is ball shaped, or other shapes. The difference between the speaker and the other speakers mainly lies in its acoustic radiation mode, the cone loudspeaker and dome loudspeaker is composed of a vibrating diaphragm directly encouraged the surrounding air will sound radiated out of the direct radiation, and horn loudspeaker is the diaphragm generates sound the horn radiation into space, and indirectly radiation. Horn loudspeaker biggest advantage is high efficiency, harmonic distortion is smaller and strong direction, but the band is narrow, poor low-frequency response. So much as a speaker system, the use of high and medium. < br / > frequency amplifier according to the burst frequency, can be divided into the bass speaker, mediant loudspeaker, tweeter, full band loudspeaker.
1, bass speaker: the main player of the low frequency signal is called the bass speaker, the bass performance is very good. Bass speaker for the lower limit of low frequency playback down as far as possible extension and the caliber of the speaker do are relatively large, generally 200mm, 300-380mm specifications of different caliber woofer, with large input power. In order to improve the tolerance value of the amplitude of the vibration cone, often with soft and wide support edge, such as edge, edge, edge skin insulation etc.. Under normal circumstances, the larger the bass speaker's caliber, the better the low frequency sound quality, the greater the input power.
2、Midrange speaker: speaker mainly play the intermediate frequency signal known as midrange loudspeaker. Can achieve convergence of frequency Squawker woofer and tweeter's music playback. Because if accounted for the entire range of leading range and feeling of the human ear of intermediate frequency than other bands sensitive and mediant loudspeaker sound quality requirement is high. A cone shaped, dome and horn type etc.. As the main performance requirement is the mediant loudspeaker, sound pressure frequency characteristics of Qu Xianping bear, small distortion, good directivity.
3, high pitched speakers: the main player of the high frequency signal is called the high pitched speakers. Treble speaker for playback of high frequency limit frequency access to human ears upper limit of hearing frequency 20KHz and smaller diameter, membrane vibration is tough. And low, mediant loudspeaker compared, tweeter performance requirements in addition to the same and the tenor unit, also called the playback frequency upper limit to the high input capacity to. The commonly used high - frequency speaker is a variety of forms, such as paper basin, Hira Igata, ball top, ribbon, etc..
4, full frequency speaker: full frequency speaker is refers to the ability to also cover bass, midrange and treble the band speakers can play the whole range of audio signals. The theoretical frequency range is from tens of Hz to 20kHz, but in fact it is very difficult to use a speaker, so most of them are made of double paper basin speakers or coaxial speakers. Double paper basin speakers in the large diameter of the speaker with a small caliber of the paper bowl, used to replay the high frequency sound signal, which is conducive to the improvement of the upper limit value of the frequency response. Coaxial speaker is a two different caliber of the bass speaker with a high pitched speakers installed on the same central axis. < br / >, speaker performance index < br / > speaker is key parts of the speaker system (commonly known as the speaker), speaker sound reproduction quality is mainly composed of the performance index of the speaker decided and determine the set of playback indicator. The performance index of the speaker mainly has the rated power, the rated impedance, the frequency characteristic, the harmonic distortion, the sensitivity, the direction and so on.
The performance of the pros and cons of the speaker mainly through the following indicators to measure:
1, rated power (W) < br / > the speaker's rated power is refers to a loudspeaker to the output power of the work for a long time, also known as no distortion power, which are generally marked on the nameplate of the rear end of the speaker. When the speaker works at the rated power, the voice coil will not produce overheating or mechanical vibration overload phenomenon, the sound does not show distortion. Rated power is a kind of average power, and actually speaker in state power, it change with the input audio signal strength, in weak music and sound signal peak pulse signal will exceed the rated power many times, due to the short duration without damage to the speaker, but there may be distorted. Therefore, in order to ensure that the peak pulse still can get a good sound quality, speakers need to stay enough power margin. The maximum power that the general speaker can follow is 2-4 times the rated power.
2、Frequency characteristic(Hz)
Frequency is a measure of speaker playback bandwidth index. Should be able to replay 20Hz-2000Hz ear audible range high fidelity audio speaker system requirements system. Due to using one speaker is not easy to achieve the range. Therefore, the high fidelity speaker system by high, middle and low three speakers to achieve full band replay coverage. In addition, the frequency characteristic of the high fidelity speaker should be flat, otherwise it will introduce the frequency distortion of the replay. High fidelity audio speaker system requirements in playback frequency range frequency characteristic not flatness is less than 10dB. The nominal impedance of the
, the rated impedance (
3) is the ratio of the speaker to the voltage at the input end of the speaker and the current flowing through the speaker at the rated state. Now, the rated impedance of the speakers are generally 2, 4, 16, 32, 8 and so on. < br / > speakers rated impedance is measured in Hz signal input voltage, and the loudspeaker voice coil DC resistance R straight about 0.9R amount. DC impedance
speaker (DCR) and AC impedance (ACR) between the ratio of about 1.1; ACR/ DCR = 0.925
4、Harmonic distortion (TMD%) < br / > speaker distortion has a lot of kinds, common have harmonic distortion (many by speaker magnetic field inhomogeneity and vibration system distortion caused by, often happen at low frequencies), intermodulation distortion (distortion due to two different frequency signals at the same time with a loudspeaker, mutual modulation caused by the degradation of sound quality) and transient (due to inertia vibration system can not follow the change of signal change, causing the signal distortion). When the harmonic distortion is reproduced, the harmonic components of the original signal are added. The harmonic distortion of the loudspeaker is derived from the nonlinear distortion of the magnetic field, the characteristics of the vibration film, the displacement of the voice coil. At present, the harmonic distortion of the better speaker is not more than 5%.
5, sensitivity (dB/W)
The sensitivity of the speaker is usually measured by the sound pressure of the loudspeaker, when the input power is 1W of the noise voltage. The sensitivity is a measure of the speaker of the audio signal in detail whether the reproduction index slip over nothing whether big or small. The higher the sensitivity, the speaker's response to all the details of the audio signal. The sensitivity of the Hi-Fi (high fidelity) speakers should be greater than 86dB/W. The radiation of
6 and directional
speakers in different directions is different, and the sound pressure frequency characteristic is different, which is called the directivity of the loudspeaker. It is related to the size of the speaker, the diameter of the pointed at the point of a large, wide range of hours. Directivity is also related to frequency, generally speaking, there is no obvious directional signal to 250Hz. High frequency signal of the following 1.5kHz has obvious directivity. < - magnet -- >!