Discussion on the selection of frequency dividing points in loudspeaker system

    The choice of frequency division point is a technical work, involving many aspects of knowledge, such as speaker unit knowledge, auditory physiology knowledge, music literacy, etc., more complex, but also more difficult to master, which is also the root of the speaker system personalized. In general, the home speaker system usually adopts a two-frequency or three-frequency design, and the two designs have different requirements for the unit, but there is a basic principle that needs to be grasped in the range of the human voice frequency band as far as possible not to divide the frequency. Because the human ear has a resonance peak near 3000Hz, that is to say, the human ear is particularly sensitive to sounds around 3000Hz, if you are not very sure, when doing the frequency division design, try not to choose the frequency division point here; At the same time, the voice of the person can be about 4.5kHz, so that the frequency division after 5kHz May be greater for the designer; Of course, people familiar with the design of the speaker system know that many things are contradictory on electroacoustics, most of the time is in the balance, try to find a compromise and the most satisfactory scheme, the same is true on the choice of frequency division points above, especially for the two-frequency speaker system, the bass unit axial frequency response can even be more than 10kHz, But once it deviates from the axis, it will be found that the frequency response is very poor, which is usually referred to as the directivity problem, so in the design of the speaker system, do not take into account the pointing characteristics of the speaker unit, not a mature design, such as 8-inch speaker unit, if the use of exponential paper basin can even do more than 8kHz frequency band, but if you examine its pointing characteristics, It will be found that after a deviation of 30 degrees, the frequency response after 3kHz~4kHz is significantly worse, so when used as the bass unit of the two-frequency speaker system, it can only be used about 3kHz at most, and the crossover point setting should also be about 3kHz, so the design of the two-frequency speaker system with 8-inch speaker mono is an embarrassing choice, and there are not many successful cases. Because the electroacoustic design itself is a contradiction, the requirement of such a wide frequency band must sacrifice a lot of other performance, such as power, efficiency, sensitivity, etc., and can only make a compromise choice. There is no doubt that the design of the three-frequency speaker system should be a lot more calm, here also hope that in the human voice band (especially the middle and high frequency part) as far as possible not to divide the frequency, and the upper and lower limits of the working band of the mezzo speaker should be at least higher than 3 octave (FHFL>8) so as to ensure that the frequency band is flat.

    1) The frequency division point should be higher than the resonant frequency of the speaker monomer one octave or more;

    2) Effective frequency range and frequency response;

    3) pointing characteristics;

    4) Power bearing capacity;

    5) Musical instrument spectrum;

    6) speech spectrum;

    7) Characteristics of hearing;