The speaker is also called the "horn". It is a very common electro-acoustic transducing device, which can be seen in audible electrical and electronic equipment.
The speaker is one of the weakest devices in audio equipment, and it is one of the most important components for sound effects. There are many different types of speakers, and the prices vary greatly. Audio power passes through electromagnetic, piezoelectric or electrostatic effects, causing the cone or diaphragm to vibrate and resonate (resonate) with the surrounding air to produce sound. According to the conversion mechanism and structure, the split coil type (electric type), capacitive type (electrostatic type), piezoelectric type (crystal or ceramic), electromagnetic type (pressure spring type), electric ion type and pneumatic type speaker, etc. The speaker has the advantages of good electroacoustic performance, firm structure and low cost, and is widely used; according to the sound radiation material, the paper basin type, the horn type, the diaphragm type; the paper cone shape is divided into round, oval, double paper cone and rubber Folding ring; sub-bass, mid-range, high-pitched according to working frequency, and some are also divided into recorder-specific, TV-specific, ordinary and high-fidelity speakers; low-impedance and high-impedance according to voice coil impedance; Sound and so on.
Speakers are divided into built-in speakers and external speakers, while external speakers are commonly referred to as speakers. The built-in speaker means that the MP4 player has a built-in speaker, so that the user can listen to the sound of the MP4 player through the headphone jack or through the built-in speaker. The MP4 player with built-in speaker eliminates the need for an external speaker and avoids the inconvenience of wearing a headset for a long time.
Speaker construction
Our most common electric cone cone speaker. Electric cone-shaped speakers are often used as paper cone speakers. Although the diaphragm is still dominated by paper cones, many polymer diaphragms and metal diaphragms have appeared at the same time. It is. Conical cone speakers are mainly composed of magnetic circuit system (permanent magnet, core column, magnetic guide plate), vibration system (paper cone, voice coil) and support auxiliary system (centering piece, basin frame, cushion). Partial composition.
1. Voice coil: The voice coil is the driving unit of the cone cone speaker. It is wound on the paper tube in two layers with a very thin copper wire. It is usually wound around several tens of turns and placed on the core and magnetically permeable. The magnetic structure of the plate is formed. The voice coil is fixed with the paper cone. When the sound current signal enters the voice coil, the voice coil vibration drives the paper cone to vibrate.
2. Paper cone: There are many kinds of materials used for the cone diaphragm of the cone cone speaker. There are two types of natural fiber and man-made fiber. Natural fibers are usually made of cotton, wood, wool, silk, etc., and artificial fibers are just made of rayon, nylon, and glass fiber. Since the paper cone is the sound radiating device of the speaker, the sounding performance of the speaker is determined to a considerable extent, so no matter which kind of paper cone, 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 cone along the speaker and limit the lateral movement, and at the same time, it acts to block the front and back of the paper cone. In addition to the material of the paper cone, the material of the folding ring is also bonded to the paper cone by hot pressing using plastic, natural rubber or the like.
4. Centering piece: The centering piece is used to support the joint of the voice coil and the paper cone to ensure that it is vertical without skewing. There are many concentric rings on the centering piece, so that the voice coil can freely move up and down in the magnetic gap without lateral movement, ensuring that the voice coil does not touch the magnetic plate. The dust cover on the centering piece is to prevent the external dust from falling into the magnetic gap, avoiding the friction between the dust and the voice coil, and causing the speaker to produce an abnormal sound.
