Speakers are also called "speakers". It is a very common electroacoustic energy conversion device, which can be seen in the electronic and electrical equipment making sound.
Composition structure
Loudspeaker is a kind of energy conversion device that converts electrical signal into acoustic signal. The performance of loudspeaker has a great impact on sound quality. Loudspeaker is the weakest device in audio equipment, and it is the most important component for audio effect.
There are many kinds of speakers, and the prices vary greatly. Audio electric energy makes its paper basin or diaphragm vibrate and resonate with the surrounding air through electromagnetic, piezoelectric or electrostatic effects.
Low grade plastic speakers have no sound quality because of their thin box, which can not overcome resonance (some designed plastic speakers are far better than inferior wooden speakers); Wooden speakers reduce the sound pollution caused by box resonance, and the sound quality is generally better than plastic speakers.
Usually, multimedia speakers are designed with two units and two frequency division. A smaller speaker is responsible for the output of medium and high tones, while another larger speaker is responsible for the output of medium and low tones.
The materials of these two speakers should be considered when selecting the speaker: the tweeter unit of the multimedia active speaker is now dominated by the soft ball top (in addition to the titanium film ball top used for analog sound source), which can reduce the stiff feeling of high-frequency signal and give people a gentle, smooth and greasy feeling when combined with the digital sound source.
Multimedia speakers are now dominated by soft ball tops such as high-quality silk film and low-cost PV film.
Bass unit, which determines the sound characteristics of the speaker, is relatively important to choose. The most common are the following: paper basin, adhesive paper basin, paper-based wool basin, tight pressing basin, etc.
The paper basin has natural sound, low cost, good rigidity, light material and high sensitivity. The disadvantages are poor moisture resistance and difficult to control the consistency during manufacturing. However, the paper basin is made everywhere in the top hifi system because the sound output is very average and the reducibility is good.
Bulletproof cloth, with wide frequency response and low distortion, is the first choice for those who love strong bass. Its disadvantages are high cost, complex production process, low sensitivity and light music effect.
The wool woven basin has a soft texture. It performs very well for soft music and light music, but the bass effect is poor and lacks strength and shock.
PP (polypropylene) basin, which is widely popular in high-grade speakers, has good consistency, low distortion and commendable performance in all aspects. In addition, fiber diaphragm and composite diaphragm are rarely used in popular speakers due to their high price.
Naturally, the larger the speaker size, the better. Large caliber bass speakers can perform better in the low-frequency part, which can be selected in the purchase. Speakers made with high-performance speakers mean lower transient distortion and better sound quality.
Most of the speakers of ordinary multimedia speakers are between 3 and 5 inches. Speakers made with high-performance speakers also mean lower transient distortion and better sound quality.
Our most common electric cone-shaped paper basin speaker. In the past, we often referred to the electric conical loudspeaker as the paper basin loudspeaker. Although the diaphragm was still dominated by the paper basin in 2014, there were many polymer diaphragm and metal diaphragm at the same time, which is worthy of the name of the conical loudspeaker.
The conical paper basin loudspeaker is generally composed of three parts: magnetic circuit system (permanent magnet, core column and magnetic guide plate), vibration system (paper basin and voice coil) and support auxiliary system (centering support, basin frame and cushion edge).
1. Voice coil: the voice coil is the driving unit of the cone-shaped paper basin loudspeaker. It is wound on the paper tube in two layers with a very thin copper conductor. It is generally wound with dozens of turns, also known as the coil, and placed in the magnetic gap composed of the magnetic core column and the magnetic plate.
The voice coil and the paper basin are fixed together. When the sound current signal is connected to the voice coil, the voice coil vibration drives the paper basin vibration.
2. Paper basin: there are many kinds of materials used for the conical diaphragm of conical paper basin loudspeaker, generally including natural fiber and man-made fiber. Natural fibers often use cotton, wood, wool, silk, etc., while man-made fibers use man-made silk, nylon, glass fiber, etc. As the paper basin is the sound radiation device of the loudspeaker, which determines the sound reproduction performance of the loudspeaker to a considerable extent, no matter which kind of paper basin is required to be light and rigid, and can not be deformed due to the change of ambient temperature and humidity.
3. Folding ring: the folding ring is set to ensure the axial movement of the paper basin along the loudspeaker and limit the transverse movement. At the same time, it plays the role of blocking the air flow in front of and behind the paper basin. The material of the folding ring is not only commonly used as the material of the paper basin, but also bonded to the paper basin by hot pressing with plastics, natural rubber, etc.
4. Centering support: the centering support is used to support the joint of voice coil and paper basin to ensure that it is vertical without skew. There are many concentric rings on the centering support, so that the voice coil can move up and down freely in the magnetic gap without transverse movement, so as to ensure that the voice coil does not collide with the magnetic guide plate.
The dust cover on the centering support is to prevent external dust from falling magnetic gap and avoid friction between dust and voice coil, resulting in abnormal sound of loudspeaker.