The appearance of the speakers is diverse, most of them are rectangular, so what about other speaker shapes? The editor below collects and organizes the speaker shape classification for everyone, I hope it will be helpful to the sound engineers.
1. (Closed Enclosure)
The simplest structure of the speaker system, 1923 was proposed by Frederick, composed of speaker units installed in a fully sealed box. It can completely block the forward and backward radiated sound waves of the loudspeaker, but because of the existence of the closed box, the rigidity of the loudspeaker's moving mass is added to resonate, so that the lowest resonant frequency of the loudspeaker is increased. The sound and color of airtight speakers are a bit deep, but the low sound analysis is good. When using the usual hard-folded ring speakers, in order to obtain satisfactory low sound reproduction, a large cabinet with a large volume is required. Most of the new airtight speakers choose the appropriate Q value The high compliance speaker. Using the elastic effect of the compressed air quality closed in the box, although the speaker is installed in a smaller box, the air cushion behind the cone will exert a reaction force on the cone, so this small closed speaker is also called an air cushion speaker .
2. (Bass-Reflex Enclosure)
Also called Acoustical Phase Inverter, created by Thuras in 1930. In its load, there is a sound port opening on a panel of the box. The opening position and shape are various, but most of the holes are also equipped with sound tubes. The connection between the internal volume of the box and the sound duct hole is based on the principle of resonance, and resonance occurs at a certain frequency, which is called the anti-resonance frequency. The sound waves radiated from the rear of the loudspeaker are inverted through the guide tube, and then radiated from the sound port to the front, and are superimposed in phase with the sound waves radiated from the front of the loudspeaker. It can provide a wider bandwidth, higher sensitivity, and smaller distortion. Ideally, the lower limit of the low frequency playback frequency can be as much as 20% lower than the speaker resonance frequency. This kind of loudspeaker can reproduce rich low sound with a small box, and it is the most widely used type.
3. (Acoustic resistance Enclosure)
It is essentially a deformation of a phase-inverted speaker, which is filled with sound-absorbing material or structure in the sound port tube, and acts as a semi-closed box to control the phase-inversion effect, so as to buffer it, and reduce the anti-resonance frequency to broaden the low sound weight. Amplify the frequency band.
4. (Labyrinth Enclosure)
The transmission line speaker is named after the transmission line of the classical electrical theory. On the back of the speaker, there is a sound tube made of sound-absorbing wall panels, the length of which is 1/4 or 1/8 of the wavelength of the low-frequency sound. Theoretically, it attenuates the sound waves coming from the back of the cone to prevent it from being reflected to the open end and affecting the sound radiation of the subwoofer, but in fact, the transmission line speaker has a mild damping and tuning effect, adding that the speaker is near or below the resonance frequency The sound output is enhanced, and the stroke volume is reduced together with the enhancement of the low sound output. Usually, the sound ducts of this kind of speakers are mostly stacked in a labyrinth shape, so they are also called labyrinth or tortuous.
5. (Drone Cone Enclosure)
The'branch of the low-sound reflection speaker, also known as the empty cone speaker, was announced by Olson and Preston in the United States in 1954. Its opening is an empty cone without a magnetic circuit and voice coil (passive cone). Instead, the radiation generated by the passive cone oscillation and the forward radiated sound of the speaker are in the same phase working condition, and the composite sound formed by the air in the box and the passive cone support component and the passive cone mass form resonance to enhance the low sound. The main advantage of this kind of speaker is to avoid the unstable sound caused by reflection as the sound hole, even if the volume is not large, it can achieve outstanding sound radiation, so the sensitivity is high, which can effectively reduce the speaker's working amplitude and the influence of standing waves. Small, the sound is clear and clear.
6. (Coupled cavity speaker)
A box structure between a closed type and a low sound reflection type. In 1953, Henry Lang of the United States announced that its output is driven by a sound hole driven by one side of the cone, and the other side of the cone is connected to a closed box. coupling. The advantage of this type of speaker is that the amount of air propelled by the speaker at low frequencies is greatly increased, because the coupling cavity is a tuning system. When the cone movement is restricted, the output of the sound port does not exceed the sound output of a single cone, which broadens the low frequency weight. Increase the scale, so the distortion is reduced, and the receiving power increases. In 1969, the A·S·W (Acoustic Super Woofer) speaker announced by Yukihiko Kawashima of Lo-d in Japan is a coupled cavity speaker, suitable for reproducing low sounds without distortion with small-diameter long-stroke speakers.
7. (Horn type Enclosure)
For household models, the Folded Horn method is often used. Its horn mouth is coupled with a larger air load at the mouth, and the driving end has a small diameter. The back of this type of speaker is fully sealed, and the inside of the chamber The pressure is mostly on the reverse side of the speaker cone. In order to maintain a balance between the front and rear pressures of the cone, an inverted horn is installed in front of the speaker. The folding horn speaker is a derivative of the phase-inverted speaker, and its sound effect is better than the usual low-sound reflective speaker of the enclosed speaker.