The speaker is the device we use every day. I believe everyone is familiar with it. But do you know how the speaker sounds? This little tip will take you through 8 common speakers and their sounding principles.
1:Electric speaker
Also known as moving coil speakers, it is the most widely used and widely used speaker. The basic principle of its vocalization comes from Fleming's left-hand law. A current line and a magnetic line are placed perpendicularly between the north and south poles of the magnet. The wire is moved by the interaction of magnetic lines and currents. The membrane is attached to this line, and the diaphragm moves forward and backward as the current changes. At present, more than 90% of the cones are designed in a moving coil type.
2:Electromagnetic speaker
A movable neodymium iron piece (armature) is placed in the middle of a U-shaped magnet. When a current flows through the coil, the armature is magnetized and the magnet generates a repellent phenomenon, and at the same time, the diaphragm moves. This design is inexpensive but not effective, so it is often used on telephone and small earphones.
3: Inductive speaker
Similar to the electromagnetic principle, but the armature is doubled, and the two voice coils on the magnet are asymmetrical. When the signal current passes, the two armatures move with each other for different magnetic fluxes. The difference from electromagnetic is that the inductor can regenerate a lower frequency, but the efficiency is very low.
4:Electrostatic speaker
The basic principle is Coulomb's law, which is usually vacuum-vaporized with a plastic diaphragm and an inductive material such as aluminum. The two diaphragms are placed face to face. When one of them is positively charged with high voltage, the other one will sense. A small current is generated, and the sound can be emitted by pushing the air to each other. Due to the light weight and low vibration dispersion of the electrostatic monomer, it is easy to obtain a clear and transparent mid-high pitch, which has an effect on the bass power, and its efficiency is not high, and it is easy to collect dust by using a DC power source. At present, manufacturers such as Martin-Logan have successfully developed electrostatic and dynamic hybrid speakers, which solves the problem of insufficient electrostatic bass, and the electrostatic application on headphones is also extensive.
5:Flat speaker
The earliest design developed by Japan's SONY, the voice coil design is still the theme of the moving coil, but the cone diaphragm is changed into the plane diaphragm of the honeycomb structure. Because of the small hole effect, the characteristics are better, but the efficiency is also low. .
6:Ribbon speaker
Without the traditional voice coil design, the diaphragm is made of very thin metal, and current flows directly into the conductor to make it vibrate. Because its diaphragm is a voice coil, the quality is very light, the performance response is excellent, and the high frequency response is also very good. However, the efficiency and low impedance of the ribbon speaker has always been a big challenge for the amplifier, Apogee can be represented. Another way is to have a voice coil, but the voice coil is printed directly on the plastic sheet, which can solve some of the low-impedance problems, such as Magnepang's design.
7:Horn speaker
The diaphragm works by pushing the air at the bottom of the horn. Because the sound is not diffused, the efficiency is very high. However, since the shape and length of the horn affect the tone, it is not easy to replay the low frequency. Most of them are now used in giant PA systems or On the tweeter, the US Klipsch is the old horn speaker manufacturer.
8:other
The ribbon-shaped improved design developed by Dr. Haier in 1973, called the Haier loudspeaker, is theoretically excellent, but Taiwanese users are rare.
Piezoelectric is a design that uses piezoelectric materials such as titanic acid and voltage to make it stretch or shrink. Pioneer has improved piezoelectric design with high polymer and used it on their tweeters.
Ion speakers (Ion) are protons that use high-voltage discharge to make air charged. When an alternating voltage is applied, these free charged molecules will vibrate due to vibration. Currently, they can only be used at higher frequencies.
Philips has also developed Active Feedback Speakers (MFB) with active feedback lines in the speakers to significantly reduce distortion.
