Is the dynamic speaker electromagnetic induction?

Dynamic Speaker

A loudspeaker, commonly known as a speaker, is a common device that converts electrical signals into audible signals. For example, a radio receives radio waves transmitted from the air, which are demodulated and amplified by the internal circuit to become audio electrical signals. These electrical signals must be converted by a loudspeaker to become sound signals that can be heard by the human ear.

Speakers are divided into many types according to different principles. Dynamic (also called electric) speakers are the most common type. Its basic structure is to place a coil (voice coil) in the magnetic field of a magnet. When audio current passes through the coil, the coil will generate a magnetic field that changes with the audio current. This changing magnetic field interacts with the magnetic field generated by the magnet (attracting or repelling), causing the coil to vibrate.

The coil is connected to the speaker's paper cone, which drives the cone to vibrate, and the cone makes the surrounding air vibrate, which produces the sound we can hear. The principle and structure of a dynamic speaker are not complicated. We can make one by ourselves to deepen our understanding of it.

The speaker consists of two parts: the magnet and the vibration system, as shown in the figure below. The magnet consists of a magnet and a soft iron core, while the paper cone (diaphragm), centering support, voice coil and dust cover constitute the vibration system. When the audio current is passed through the voice coil of the speaker, the voice coil generates an alternating magnetic field under the action of the current, and the permanent magnet also generates a constant magnetic field with constant size and direction. Since the size and direction of the magnetic field generated by the voice coil are constantly changing with the change of the audio current, the interaction of the two magnetic fields causes the voice coil to move perpendicular to the direction of the current in the voice coil. Since the voice coil and the diaphragm are connected, the voice coil drives the diaphragm to vibrate, and the vibration of the diaphragm causes the vibration surface of the air to make a sound.

The greater the current output to the voice coil, the greater the force of its magnetic field. The greater the amplitude of the vibration of the diaphragm, the louder the sound. The high-pitched part of the Bluetooth speaker is mainly in the center of the diaphragm, and the bass part of the speaker is mainly at the edge of the diaphragm. If the edge of the speaker's diaphragm is softer and the diameter of the paper cone is larger, the bass effect of the speaker will be better.

Is the dynamic speaker electromagnetic induction?

Dynamic speakers are an application of electromagnetic induction. Dynamic speakers convert electric current into sound signals through the principle of electromagnetic induction.

The working principle of dynamic speakers is to use the phenomenon of electromagnetic induction. When current passes through the coil in the speaker, it will generate force in the magnetic field, causing the vibration system on the coil to vibrate, thereby driving the speaker cone diaphragm or vibration system, and then produce sound.

Therefore, a dynamic speaker is a device that uses the principle of electromagnetic induction to convert electric current into sound, and is one of the applications of electromagnetic induction in the field of sound.