We already know that the acoustic signal is to convert the waveform of music into the waveform of electrical signals, so we can also make the sound of music by pushing the waveform of the signal into the air as well. The equipment in the audio system that converts electrical signals into sound is the "amplified speaker", which is commonly known as the "speaker". At present, the most mainstream technology for converting electrical energy into sound waves is electromagnetic. The amplified speakers on the market today are mainly designed and produced to take the electromagnetic principle.
The complete amplified speakers will consist of several parts: the speaker unit, the crossover network, and the speaker. The speaker unit basically reverses the working principle of the microphone. The electrical signal is input to the coil on the voice coil in the magnetic system. The coil will change magnetically with the signal, and drive the voice coil to move in the magnetic system in a sound wave. The voice coil then pushes the diaphragm or cone of the speaker unit to push the air to generate sound waves, and the sound is emitted.
It is not difficult to say, but it is another matter to make the electrical signal sound as low distortion as possible according to the original waveform and response. The audio range from low frequencies (20Hz) to high frequencies (18kHz) is more than ten octaves, and a single speaker unit is structurally limited in volume to cover this audio range. However, now the technology of the full-range monoblock is mature and developed, and there are many full-range monoblocks with good performance available on the market.