1. The speaker leads are defective. Usually the voice coil lead is moldy or poorly welded. When the paper cone vibrates frequently, the breakpoint is turned on and sometimes turned off, and when the irregularity occurs, the fault does not sound.

2. The voice coil lead is broken or is about to be shorted.

3. Poor contact of the power amplifier output jack or disconnection of the speaker input line.

1. The performance of the speaker is poor, and the magnetic properties of the magnetic steel are degraded. The sensitivity of the speaker depends mainly on the magnetic properties of the permanent magnet, the quality of the cone and the pros and cons of the assembly process. The ferromagnetic object can be touched by the magnetic steel, and the magnetic strength of the magnetic steel can be roughly estimated according to the magnitude of the attraction. If the magnetic property is too weak, only the speaker can be replaced.

2. The magnetic core is loose. When the magnetic core of the speaker is loose, it will be sucked to one side by the magnetic conductive plate, so that the voice coil is squeezed to hinder the normal sound. You can use the hand to gently press the paper cone during maintenance. If you press it, the voice coil may be pressed by the core post. It needs to be disassembled and re-adhered before it can be used again.

3. The divider is abnormal. When there are components in the crossover, the signal in the corresponding frequency band is blocked, and the speaker in the band has a volume glitch. It is important to check whether the crossover capacitor connected in parallel with the woofer is short-circuited, and whether the crossover inductor coil connected in parallel with the tweeter is short-circuited between layers.