Frequency response, early commonly known as power bandwidth, refers to the harmonic distortion does not exceed the specified value, the 1/2 rated power frequency band width of the power amplifier, namely the frequency band included between the two frequency points of concave and convex end drop -3dB, called power bandwidth. Damping coefficient, mainly for low frequency, is a very important technical parameter that directly affects the quality of low sound.

As we all know, the larger the caliber of the horn, the better the relatively low voice, but the larger the basin of the movement inertia is also increased, this inertia makes it difficult to synchronizes with the audio signal movement, often show the sound of cloudy, especially in 100-400Hz low frequency, simple formation of sound staining, make people sound blurred, very unnatural. Some of the modified car's low horn, low frequency signal when the chatter is strong, low tail stern, which is caused by the sound basin inertia.

In power amplifier design engineer for power amplifier to adopt some technical measures, such as selection of multi-tube parallel, low internal resistance (milliohm level) high power tube, progressive work voltage, choose high quality wire, etc., to progress, damping coefficient, so that it can target the horn inertia motion, "electrical damping effect, make the movement and the audio signal synchronous movement of basin.