① The mobile phone can't directly drive high-power speakers (tens of W to hundreds of W) because the power of the mobile phone itself is too small (about several mW). There must be a device called audio power amplifier between the mobile phone and the high-power speaker or sound box, which is called power amplifier for short. High-power speakers or sound boxes are driven by power amplifiers, and mobile phones are used as sound sources.

② There are two kinds of wires connected between the mobile phone and the power amplifier or low-power audio, one is a 3.5mm public-to-public audio cable, and the other is a 3.5mm dual-showerhead audio cable.

The former is mostly used for low-power audio (such as multimedia active speakers), while the latter is mostly used for the connection of high-power amplifiers (household amplifiers, etc.). ).