What is a low frequency speaker

- Sep 05, 2019-

For a variety of different speakers, the quality factor of the low-frequency speaker-Q0 value requirements are different. For closed boxes and inverter boxes, Q0 is generally the best between 0.3 and 0.6. In general, the larger the diameter of the low-frequency speaker, the diameter of the magnet and the voice coil, the better the low-frequency playback performance and transient characteristics, and the higher the sensitivity. The structure of the woofer is mostly cone-shaped, and a few are flat. There are many types of diaphragms in the woofer, including aluminum alloy diaphragm, aluminum-magnesium alloy diaphragm, ceramic diaphragm, carbon fiber diaphragm, bulletproof cloth diaphragm, glass fiber diaphragm, acrylic diaphragm, paper diaphragm and so on. The bass unit using aluminum alloy diaphragm and glass fiber diaphragm is generally smaller in diameter and can withstand larger power, while the bass unit using reinforced paper cone and glass fiber diaphragm is more accurate when replaying music, and the overall balance is good.

Q0: The figure of merit of a speaker unit is an important parameter that must be understood before designing and manufacturing a speaker. On the impedance characteristic curve of the speaker unit, it shows that the sharpness of the impedance peak at the resonance frequency of the impedance curve reflects the damping state of the speaker vibration system to a certain extent, referred to as the Q0 value. The higher the quality factor of the speaker unit, The more difficult it is to control the resonant frequency. The low frequency characteristics of a speaker are usually determined by the quality factor value and resonance frequency of the speaker unit, where the size of the quality factor is related to the sound pressure output by the speaker unit at the resonance frequency. When the Q0 value is too low, the output sound pressure of the speaker drops quickly before it reaches F0, and the speaker is in an overdamped state, causing the low-frequency attenuation to be excessive. When the Q0 value is too high, the speaker is under-damped, and the low frequency is excessively strengthened. The larger the Q0 value, the steeper the peak. Therefore, we say that the quality factor of the speaker can neither be too high nor too low, usually we take its critical damping value Q0 equal to 0.5-5. 7 as the optimal value range.