The frequency divider refers to distinguish the sound signals of different frequency bands, respectively amplify them, and then send them to speakers in the corresponding frequency bands for replay. When reproducing high-quality sound, electronic frequency division processing is required.
The frequency divider is a circuit device in the speaker, used to separate the input analog audio signal into different parts such as treble, midrange and bass, and then sent to the corresponding high, middle and woofer units for playback. The reason for this is that no single speaker can perfectly reproduce the sound in all frequency bands.
The crossover is the "brain" in the speaker, which is crucial to the sound quality. The music signal output by the power amplifier must be processed by the filter element in the frequency divider to let the signal of a specific frequency of each unit pass. It is necessary to design the frequency divider of the speaker scientifically, reasonably and rigorously to effectively modify the different characteristics of the speaker unit and optimize the combination so that each unit can develop its strengths and avoid its shortcomings. Only smooth, accurate image phase can make the high, middle, and low-pitched music layer have clear, coherent, bright, comfortable, wide, and natural sound quality effects.
In a speaker system, people call the cabinet, crossover circuit, and speaker unit as the three major parts of the speaker system, and the crossover is the "brain" in the speaker. Can the crossover circuit restore the speaker system with high quality? Electroacoustic signals play an extremely important role. Especially in the middle and high frequency parts, the role played by the frequency dividing circuit is more obvious.
In general, the frequency divider can be defined as: the input electrical signal is separated into two separate signals, and the bandwidth of each signal is smaller than the bandwidth of the original signal. This is composed of one or more pairs of filters The constituted device is called a frequency divider. It may also be called "frequency allocation network".
The frequency divider is usually composed of a high-pass (low-cut) filter (referred to as HPF) and a low-pass (high-cut) filter (referred to as LPF). A filter is a frequency selection device that can block other frequencies from passing through the selected frequency. The filter usually has the following three parameters: cutoff frequency, network type, and slope. The cutoff frequency refers to the frequency at which the filter response drops to a certain point below its maximum level, which is usually 0.707 times or 0.5 times the maximum level, or the frequency at which it drops by 3dB or 6dB.
In general, the frequency divider includes three basic parameters: frequency division point, path and order. The meaning of each parameter is introduced in detail below.
Crossover point
The crossover point refers to the dividing point between the high-pass, band-pass and low-pass filters of the crossover. It is usually expressed in terms of frequency and the unit is Hertz. The high and low frequency two-way speakers have only one crossover point, and the high, middle and low three-way speakers have two crossover points. The crossover points should be determined according to the frequency characteristics and power distribution of the speaker unit or speaker in each frequency band.
The crossover point is usually defined as the frequency at which the response of two frequency dividers (generally composed of an LPF and an HPF) cross each other, which may be the frequency division of the electrical characteristics of the two electronic frequency dividers (driven or active) Point, or the crossover point on the two acoustic filters. Any speaker unit is essentially a filter, and each has their own inherent high-pass and low-pass filters, as well as inherent cut-off frequency, slope, and network type.
The overall acoustic crossover point of a system depends on the mathematical combination of the frequency response of the electronic filter and the speaker unit in this system. When an electronic filter is added to an acoustic filter system, their frequency response will be superimposed to form a brand new Response curve.
The difference in sound level / sensitivity between two different units, as well as the phase lag of high-frequency devices, are obvious. The high-frequency part is likely to be fixed to a horn with a long throat, so it produces a delay relative to the low-frequency speaker. In order to better reproduce the signal of the system, the newly developed frequency divider requires a smooth frequency response curve.
Selection principle
The choice of crossover point is more flexible, but there are several dominant theories in general.
1. For the frequency characteristics of the high and low speakers, the crossover point should be selected between the two to make the full frequency band smooth.
2. High and low speakers are suitable for the sound performance of different frequencies, some units are suitable, and some are not suitable.
3. The quality of the tweeter, especially when the crossover frequency is low, requires high timbre and power carrying capacity.
Method of choosing
1. Consider the practical boundary frequency f = 345 / d (d = effective diameter of the unit diaphragm) for the directivity of the middle and low units. Generally, the boundary frequency of the 8 "unit is 2k, the boundary frequency of the 6.5" unit is 2.7k, the 5 "unit is 3.4k, and the 4" unit is 4.3k. In other words, when using the above units, the crossover frequency cannot be greater than the practical boundary frequency corresponding to each unit.
2. Considering the resonance frequency of the tweeter, the crossover frequency should be greater than three times the resonance frequency. In other words, from the point of view of the tweeter, the frequency division point should usually be greater than 2.5k.
3. Consider the mid-bass unit high-end response Fh, usually the crossover frequency should not be greater than 1 / 2Fh. In fact, the above conditions for two-way speakers are difficult to meet at the same time. At this time, the designer should have a better choice among the three. However, it must be emphasized that the first condition, that is, the practical boundary frequency should be satisfied first.
4. In the case of three frequency division, the farther the two frequency division points should be separated (should be above three octave bands), the better the combined system response will be. Otherwise, complex interference radiation will occur.
5. The crossover point of bass and midrange should consider the problem of vocal and sound image localization. The reproduction of vocals should be undertaken by the mid-range unit as much as possible to avoid excessive changes in the sound localization tone of the vocals. This is often easily overlooked by designers. Usually this crossover point should be 200-300HZ.
ZTTEK Batteries, For 5G backup base station .Customize the lithium ion battery packs according to the application and product requirements of the customers.
Lithium ion battery integration requires a special set of skill and expertise to optimize the performance and battery life.ZTTEK Batteries , using the most advanced technology delivers the best quality battery packs.
Our batteries are safe to use, better performance, higher shelf life and a very low maintenance cost.
48V200Ah Lithium Ion Battery,Lifepo4 Battery 48V 200Ah,Rechargeable Battery 48V 200Ah,48V 200Ah Lifepo4 Battery Pack
Jiangsu Zhitai New Energy Technology Co.,Ltd , https://www.zhitainewenergy.com