A headset consists mainly of four parts: a headband, left and right sounding units, earmuffs and leads.

The function of the headband is to fix the left and right sounding units, and place them on both sides of the head. Its structure and its connection with the unit determine the pressure of the headband and the earmuffs on the head, which affects the wearing comfort of the earphone.

The earmuff is the part of the head that is in contact with the sounding unit. It is essential for the dynamic earphone. Its function is to reflect the low frequency back to ensure low frequency playback. Earmuffs are generally available in two styles, one on the ear, called the Supra-aural, and the other on the cup, around the ear, called the circumnaural. The earmuffs should be as soft and comfortable as possible, and the inside is usually filled with a sponge and covered with leather or flannel. The material used in the earmuff absorbs the mid-frequency and high-frequency, which forms the ear at a distance from the diaphragm and forms a chamber between the earphone and the head. The large ear-shaped earmuffs have a large internal space, and the sound can act on the auricle to form a better sense of space. A well-designed earphone has fully considered the role of the earmuff, so the earmuffs of the high-end earphones can not be damaged or replaced at will.

The lead wire of the earphone is the connection line between the output end of the earphone amplifier circuit and the voice coil of the earphone. The high quality earphone wire often adopts an oxygen-free copper (OFC) wire with multiple cores, and undergoes strict insulation and shielding treatment to prevent impurities in the copper from transmitting signals. Affects interference with outside clutter. The end of the headphone cord is a plug, available in two sizes: 6.35mm and 3.5mm, which is the size of the plug, 6.35mm plug for professional audio and civilian audio equipment, and 3.5mm plug for portable equipment. General high-fidelity headphones will provide plug converters to ensure the use of headphones on a variety of devices. The plugs of the high-end headphones are gold-plated. This is not for the sake of beauty. It is mainly to prevent the plug from oxidizing and affecting the sound. Because the gold is smooth and soft, it can also provide the largest contact area. Low-end headphones often use nickel-plated plugs, which can prevent oxidation and have a negative impact on sound.

The sounding unit of the earphone is the most complicated and technically capable part of the earphone design. The working principle of the dynamic earphone is the same as that of the dynamic ring speaker. After the audio signal is input into the voice coil, the electromagnetic field generated by the voice coil changes with the change of the signal, and the changing electromagnetic field interacts with the magnetic circuit to promote the movement of the voice coil and the diaphragm. Push the air to sound. The dynamic earphone sounding unit is mainly composed of three parts: an acoustic structure such as a magnetic circuit system, a vibration system, a cavity and a hole.

The magnetic circuit system consists of a constant magnet, a pole plate and a pole piece, which has a direct impact on the performance and reliability of the earphone. One side of the constant magnet is a flat plate and the other side is a "T" shaped pole piece. A small annular magnetic gap is formed between the plate and the pole piece, and the voice coil of the vibration system is suspended in this gap. Usually, the constant magnet used in high-fidelity headphones is a high-performance neodymium iron magnet. The earlier earphone models have expensive samarium-cobalt magnets, and the low-end headphones generally use ferrite magnets. The design of the magnetic circuit system is complicated.

The vibration system consists of a voice coil and a diaphragm. The diaphragm is a sound radiating element that pushes the air to vibrate and directly affect the frequency response and sensitivity. Its performance depends primarily on the materials, shapes and manufacturing processes. The material for manufacturing the diaphragm requires the mass per unit area to be as small as possible, high in mechanical strength, and large in internal damping. The higher the mechanical strength and the lighter the weight, the wider the frequency range is, the higher the output sound pressure level is; the internal damping is large, and the distortion is small under large signals. Nowadays, the diaphragm uses a polyester film that is easy to thermoform, light in weight and rigid. Some companies have developed new materials for the diaphragm, such as the "bio-vibration" made by SONY from cellulose isolated from Acetobacter. The membrane is used for its advanced headphones and earplugs, and the high frequency is excellent. The diaphragm is usually circular, the center is designed with a convex arc shape, and the surrounding is designed with reinforcing ribs, which can strengthen the rigidity of the diaphragm and increase the effective area of the diaphragm. Sometimes a small hole is machined in the non-vibrating portion of the diaphragm for the purpose of air pressure balance. The diaphragm manufacturing process is very demanding, and the various differences in the processing are extremely strict.

The voice coil is the vibration source of the dynamic earphone, and most of the parameters of the earphone, such as impedance, sensitivity, and rated power, are related to it. The performance of the voice coil depends mainly on the material used and the number of turns of the voice coil, ie the length of the voice coil wire. The material of the voice coil is generally copper enameled wire. The high-grade earphones often use oxygen-free copper enameled wire and copper-clad aluminum enameled wire. The latter has the advantages of copper enameled wire, but the quality is lighter, and silver is also used as the voice coil material. The cross section of the voice coil's enameled wire is mostly circular, and also has a triangular and regular hexagonal cross section, so that the line is more tightly combined, the capacitance between the lines is reduced, and the quality of the voice coil is further reduced. The size of the voice coil also has a certain impact on the performance of the headphones. The voice coil vibrates in the magnetic gap, and its diameter should ensure that the voice coil is located in the center of the magnetic gap and will not collide with the plates and pole pieces when vibrating. On the other hand, since the magnetic field of the magnetic gap at the surface of the plate is not uniform, the movement of the coil in a non-uniform magnetic field reduces the conversion efficiency of the electro-acoustic energy and causes distortion of the earphone, so the height of the voice coil must have A proper choice.

Acoustic structures such as cavities and holes are an important part of the performance of the headphones. The fixed magnetic circuit system and the vibration system are a plastic frame called a countertop, and the edge of the diaphragm is bonded to the frame. This frame must be rigid enough not to deform due to the fixed magnetic circuit and the vibrating portion, and to transmit vibration as little as possible. Behind the magnetic circuit and the vibration system is the outer casing of the earphone. A cavity is formed between the outer casing and the table. The size and shape of the cavity, the position, type and quantity of the internally filled damping material affect the frequency response of the earphone. The larger the body, the easier it is to obtain high-quality, deep-dive low frequencies.