The sound box is a mixed sound source of direct sound and diffracted sound during the use of the sound box due to the influence of various aspects such as the structural form, the selection of the box material, and the accuracy of processing. Early labyrinth speakers relied on a longer bass pipe in the speaker box to enhance low-frequency energy. Although the bass relief hole is located directly in front of the speaker panel, the low frequency part it releases is enhanced by multiple reflections from the longer bass channel. Therefore, this part of the low frequency has a strong characteristic of diffracted sound-this is its unique localization uncertainty. The low frequency end of the frequency response of the labyrinth speaker is also more prone to slight disconnection.
The labyrinth speaker is the product of the era of hard folding ring woofer. A few decades ago, the woofer of the loudspeaker had a folding ring on the edge that was mostly a rigid folding ring, made of cloth material with glue added. The folding ring of most civilian products is basically the extension of the paper diaphragm. Due to the high rigidity of the folding ring itself and the small stroke range of the diaphragm, it is called a rigid folding ring unit. The low frequency f L of this type of woofer is relatively high, generally in the range of tens of Hz to 100 Hz, and it works in a vibrating sound state. Due to its own low frequency f L is not low enough and the vibration-type sounding state, it is appropriate to use a labyrinth box structure to enhance the bass.
With the advancement of speaker unit manufacturing technology, a soft folding ring woofer with rubber edges and foam edges was introduced. This type of bass unit has a long stroke, and its own f L is low, generally tens of Hz, and the lowest can reach a few Hz. The soft folding ring woofer works in the piston-shaped sounding state in the low frequency band, so no labyrinth box is needed to enhance the low frequency. Some manufacturers and enthusiasts who do not have a good understanding of the sound generation principle of the speaker have added a long labyrinth bass channel to the soft folding ring woofer, which has caused the bad consequences of poor transient characteristics of the speaker and severe bass disconnection. This is also the theoretical basis for why manufacturers with strong modern technical strength have eliminated the labyrinth speakers.
The working state of the inverted speaker is also in the mixed working state of direct sound, diffraction and reflected sound. Since the length of the inverter tube of the inverter speaker is shorter and the distance to the woofer unit is shorter, the diffraction and reflection ratios of the inverter speaker during working are relatively small, and the sound and phase of the replay are more accurate. This is also the main technical basis for the inverting speakers at this stage.
There is also a type of speaker, which is a closed type speaker. This type of speaker does not have a labyrinth hole and an inverted hole. Theoretically speaking, the enclosed speaker is easy to achieve better frequency response and complete direct sound, but the actual working state is not like this. Due to the strength problem of the box material itself, the box of the closed sound box is subject to high vibration of the air in the box. Under the working state, the box will generate strong vibration (diffraction sound). Due to the semi-open state of the cabinet, the vibration of the cabinet itself will be relatively less due to the labyrinth and inverted speakers. The test curve of the enclosed speaker is relatively straight, because the test is in a low-power working state where only 1W of power is input. During normal use, the input power is much greater than 1W. Due to the restriction of the volume in the cabinet and the influence of the damping material in the cabinet, the frequency response of the low-frequency end of the enclosed speaker will be significantly deteriorated when working at high power, and the transient characteristics of the speaker are not as good as the inverted speaker.
After knowing the working characteristics of the speakers, it is easy to understand that speakers with different structures that have the same frequency response, power, and sensitivity will have very different sound and sound performances during replay.
Guangzhou Ehang Electronic Co., Ltd. , https://www.ehangmobile.com