The loudspeaker is also called "horn". It is a very commonly used electroacoustic transducer, which can be seen in the acoustic electronic and electrical equipment.

Loudspeaker is the weakest component 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 through electromagnetic, piezoelectric or electrostatic effects and produce resonance (resonance) with the surrounding air to produce sound. According to the energy conversion mechanism and structure, the electric speaker has the advantages of good electro acoustic performance, firm structure, low cost, etc., and is widely used; According to the sound radiation material, it is divided into paper basin type, horn type and diaphragm type; According to the shape of the paper pot, it can be divided into round, oval, double paper pots and rubber folding rings; According to the working frequency, it can be divided into bass, midrange and treble. Some are also divided into special audio recorders, TV sets, ordinary and high fidelity speakers, etc; According to voice coil impedance, it can be divided into low impedance and high impedance; According to the effect, it can be divided into straight radiation and ambient sound.

Speakers are divided into internal speakers and external speakers, and external speakers are generally referred to as speakers. The built-in speaker means that the MP4 player has a built-in speaker, so that users can listen to the sound of the MP4 player not only through the headphone jack, but also through the built-in speaker. The MP4 player with built-in speaker can avoid external speakers and the inconvenience of wearing headphones for a long time.

Speaker structure

Our most common electric cone cone speaker. The electric cone speaker is what we used to call a paper cone speaker. Although the diaphragm is still mainly a paper cone speaker, there are many polymer material diaphragm and metal diaphragm at the same time, which is worthy of the name of the cone speaker. The conical paper cone speaker is mainly composed of three parts: magnetic circuit system (permanent magnet, core column, magnetic guide plate), vibration system (paper cone, voice coil) and supporting auxiliary system (centering support, basin frame, padding).

1. Voice coil: The voice coil is the driving unit of the conical paper cone speaker. It is wound on the paper tube by very thin copper wires in two layers, usually dozens of times, and placed in the magnetic gap formed by the magnetic core column and the magnetic plate. The voice coil and the paper cone are fixed together. When the sound current signal is passed into the voice coil, the voice coil vibration drives the paper cone vibration.

2. Paper cone: There are many kinds of materials used for the conical diaphragm of the conical paper cone speaker, including natural fiber and artificial fiber. Natural fibers are often cotton, wood, wool, spun silk, etc., while man-made fibers are just rayon, nylon, glass fiber, etc. As the paper basin is the sound radiation device of the loudspeaker, it determines the sound release performance of the loudspeaker to a considerable extent. Therefore, no matter what kind of paper basin, it is required to be light and rigid, and cannot be deformed due to changes in 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 lateral movement, and also plays a role in blocking the air flow of the paper basin in front of and behind. The material of the folding ring is not only commonly used in the paper basin, but also used in plastic, natural rubber, etc., which are bonded to the paper basin by hot pressing.

4. Centering support piece: The centering support piece is used to support the joint part of voice coil and paper basin, ensuring that it is vertical without deflection. There are many concentric rings on the centering support piece, so that the voice coil can move up and down freely in the magnetic gap without lateral 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 into the magnetic gap, so as to prevent dust from rubbing against the voice coil and causing abnormal sound to the loudspeaker.