Master the basic details and ability of loudspeaker 2

- Sep 18, 2020-

First order splitter

The first-order splitter has a frequency division slope of 20 dB / decade (6 dB / octave), and has a phase error of 90 ° at the output. In the high pass, it has a positive 45 ° error with the input signal, and a negative 45 ° error in the low-pass aspect. There may be such an error near the frequency division point.

The first-order splitter is regarded as an ideal splitter by many audio enthusiasts, because it has good instantaneous response, that is, in the conduction band of the filter, the frequency response and phase response are very flat; in addition, it uses the least electronic components to complete the frequency division work, resulting in relatively low loss. However, due to the low slope of the first-order splitter, more unwanted signals are retained outside the conduction band. In this way, the bass unit is easy to receive the high-frequency components above the frequency division point and produce large distortion; the high-frequency unit is easy to receive the low-frequency components below the frequency division point, which is more likely to be damaged in addition to distortion.

In practical application, it is not easy to design a loudspeaker system with a first-order splitter because it must be matched with a loudspeaker unit with a very wide frequency response, and the interference between the units is more obvious due to the lower frequency division and oblique filtering, that is, the off-axis frequency response of the loudspeaker will change dramatically.

Second order splitter

The second-order splitter has exactly twice as many parts as the first. The second-order splitter has a division slope of 40 dB / decade (12 dB / octave), and twice the parts cause more 90 ° rotation because it is a steeper attenuation. This means that there is an error of 180 ° at the frequency division point, which takes 12dB as the division slope. 12dB splitter is generally used in car audio, and the common loudspeaker is also suitable for this kind of splitting mode.

This kind of splitter is the most common in passive splitter because it achieves a reasonable balance between design complexity, frequency response and treble protection. When all the units of the loudspeaker are aligned, the second-order splitter and all even order splitter can provide symmetrical polarity response.

Third and fourth order splitters

The third-order splitter has more parts, of course, its phase error is also larger. It is attenuated by 18 dB and has a division slope of 60 dB / decade (18 dB / octave). There is a phase error of 270 ° between high pass and low pass. The fourth-order splitter has an 80 dB / decade (24 dB / octave) division slope and a 360 ° phase error between high pass and low pass. This kind of splitter can ensure that the low frequency part is far away from the high sensitivity tweeter, so that the sound field is deeper, especially the 24dB bass, you can feel the deeper bass. The design of the splitter needs to be tested by the instrument, which can not be changed at will.

Three tone splitter

The advantage of high-order frequency divider is that the filter attenuation slope is larger, the frequency division effect is better, and it is also conducive to the design of frequency division compensation circuit (because the more thoroughly "divided" frequency divider, the cleaner the frequency divider is, theoretically speaking, the two signal curves after frequency division are completely consistent with the original curve, which is the real good divider).

Basic judgment of sound splitter

The splitter can completely determine the sound direction of the loudspeaker, so the design of the splitter is very important. How to design a good sound splitter? First of all, according to the characteristic curve of single unit, select the best frequency segment, and then determine the frequency division point of the loudspeaker. In addition, according to the efficiency and impedance of high and low tone unit, we should design the most suitable splitter for this speaker and monomer.

In the field of home use, the design of the splitter is to make the loudspeaker have the most flat frequency curve as far as possible. But it is not the case in professional fields, such as the loudspeaker in the ballroom. In order to make the loudspeaker have strong power, the splitter will be specially strengthened in the low and medium frequency band. In addition, the design of the splitter will also affect the efficiency of the loudspeaker. When the more parts are used, the overall efficiency of the loudspeaker will be reduced.

To sum up, you should first know what kind of sound splitting method is adopted for the loudspeaker when purchasing, which is the second-order, third-order or other design. Sometimes, the manufacturer will explain in the marketing that the sound splitting network with good materials is used, which will help the performance of the loudspeaker.

Understand the combination and configuration of monomer specifications

Another important item you can learn from the speaker specification list is the drive units used. Bookshelf type speakers are usually designed with two-way splitting design, equipped with high and low-frequency units; floor type speakers mostly use three-way split, with three or more single high, medium and low-end. And satellite speakers or entry-level multimedia speakers are mostly just a single body.

Arendal 1961 series horn. There are two to five individual loudspeakers.

It should be noted that the size of the unit, usually the higher the order of the horn, the more large the monomer. For example, two or more medium and low-frequency monomers, so that if or low-frequency output and control better. The larger the diameter of the monomer, the better the diving of the bass, the stronger the amplitude and the greater the sound pressure. But of course, these must be well matched with diaphragm, drive circuit, splitter and other components. Therefore, monomer size has reference value, but it is not an absolute indicator. Take the treble unit as an example. Half inch, 1 inch and 1 / 2 inch are common sizes, 4-6 inch is common in midrange unit, and 5-10 inch is common in bass