Low-frequency Horn

For various types of speakers, the requirements for the quality factor of low-frequency speakers - Q0 value are different. For closed and inverted boxes, the Q0 value is generally best between 0.3 and 0.6. Generally speaking, the larger the aperture, magnet, and voice coil diameter of a low-frequency horn, the better its low-frequency playback performance, transient characteristics, and sensitivity. The structural form of the bass unit is mostly cone basin type, and there are also a few flat plate types. There are various types of diaphragms for bass units, including aluminum alloy diaphragms, aluminum magnesium alloy diaphragms, ceramic diaphragms, carbon fiber diaphragms, bulletproof cloth diaphragms, glass fiber diaphragms, acrylic diaphragms, paper diaphragms, and so on. Low frequency units using aluminum alloy diaphragms and fiberglass diaphragms generally have a smaller aperture and higher power capacity, while those using reinforced paper bowls and fiberglass diaphragms produce more accurate sound reproduction and overall good balance when replaying music.
Q0: The quality factor of the speaker unit is an important parameter that must be understood before designing and manufacturing speakers. On the impedance characteristic curve of the horn unit, it represents the sharpness of the impedance peak at the resonant frequency, which to a certain extent reflects the damping state of the horn vibration system, abbreviated as Q0 value. The higher the quality factor of the horn unit, the more difficult it is to control the resonant frequency. The low-frequency characteristics of a horn are usually determined by the quality factor value and resonant frequency of the horn unit, where the magnitude of the quality factor is related to the sound pressure output by the horn unit at the resonant frequency. When the Q0 value is too low, the output sound pressure of the horn rapidly decreases before reaching F0, causing the horn to be in an over damped state, resulting in excessive low-frequency attenuation. When the Q0 value is too high, the horn is in an underdamped state, and the low frequency is excessively strengthened. The higher the Q0 value, the steeper the peak. Therefore, we say that the quality factor of a speaker cannot be too high or too low. Usually, we take its critical damping value Q0 equal to 0. 5-0. 7 is the optimal value range.