1. Different equipment:
Conventional three-level plug, corresponding to the line, left channel +, right channel +, ground -, the earphone is mainly used for listening to songs, and there is no wire-controlled microphone;
Four-level plug, mainly used for headphones with wire control or microphone, corresponding to the line, left channel +, right channel +, ground -, microphone +, headphones can listen to songs, you can also use wire control or microphone
Four-level plug, can also correspond to some hifi players, as a balanced interface, corresponding to the line, left channel +, left channel -, right channel +, right channel -, separate the negative pole of the left and right channels independently, no Like the first two, they share the same ground; for different brands of hifi players, the corresponding four-section plugs are defined differently.
2. Different interfaces:
The positions of the last two MIC and ground wires are different, which leads to dislocation, and then when listening to music, it is like listening to karaoke accompaniment. The middle three isolation rings of American Standard are generally white. The national standard is generally black in order to distinguish it.
3. Compatibility is different:
The four-stage functional difference is divided into two camps - the N version and the i version. The N version of the headset is the left channel, right channel, microphone and ground wire from left to right.
From its structure, it can be seen that the i version of the headset is suitable for digital devices such as PC and MP3. These two sets of standards are incompatible with each other, but they each occupy a huge user group, resulting in the N version of the headset and the i version of the headset market.
