What about mobile phone wire control headphones !! [Zz]

Regarding Xiaomi's headphones, many friends recently asked questions about compatibility. Can we use Nokia's headphones or HTC's headphones...

The following is an analysis of the headset connector of the mobile phone:

At present, the most standard of mobile phones is 5mm headphones, and 3.5 of headphones have two poles in history (the earliest mono headphones for WALKMAN), three Poles (walkman, MP3 stereo headphones) and quad-pole (stereo with microphone.

First, let's talk about the three-pole headphones, which are stereo headphones for general Walkman, such as Schur, magic sound, senhaiser, iron triangle, Sony, and Philips on the market. Of course these headphones can be used directly, there is no problem with listening to music, but because there is no microphone and no wire control, you can only wear headphones, carry a mobile phone, and call the phone microphone.

Mobile phone headphones (including wire-controlled headphones) are four-pole. Because of the different contact definitions, there is a large compatibility problem.

Although they are all 5mm in diameter, they seem to be standard and general, but they are actually not general.

First, the contact sequence is different. Assume that the sequence from the top of the plug to the wiring at the root of the plug is defined as A, B, C, and D:

* General mobile phones (including Nokia and Samsung) are: l, R, mic,Gnd

* Xiaomi, iPhone, and HTC are: l, R, Gnd,Mic

For details, see:

 

 

Therefore, these two types of Four-pole headphones are not applicable. For example, Samsung's ear plug-in On Xiaomi will find that the voice part is like KaraOKFor such a sound, it is normal to press and hold the call button on the headset without sound. This is mainly becauseGndAndMicMisaligned.

, except L all external links are connected to Gnd , that is to say, you can use the left-side sound channel to transmit the video to both sides of the ear. Only Gnd , L two valid contacts.

Plug the Three-pole earphone, which isGnd,MicConnectGnd, YesGnd,R,LThree valid contacts, which are enough for use by stereo signals.

For mobile phone radio functions (Gnd) Provides the external antenna function.

Similarly,3.5In terms of the video output plug, the sequence isGnd,Video,R,L.

As for the line control, it is throughMicAndGndLoop. This is different for different series of mobile phones, although the contact location is the same, it cannot guarantee compatibility.

After actual tests, Apple headphones are used on Xiaomi and there is no problem with listening to music. In line control, only the middle key is valid, the volume key is invalid, and the microphone is invalid.

WhileHTC desirehdThe headset is completely compatible with Xiaomi. All music controls (playing, pause, first and last), microphones, and call control (call and hanging up) can be used normally.

 

These two standards are the European and American standards, but the impedance of headphones designed by different manufacturers is different, resulting in incompatibility in many cases, especiallyIPhoneAlthough it is a US logo designMicImpedance ratio Generally, the headset is large, or evenIphone2AndIPhone 4OfMicThere is a big difference in impedance, it is recommended to use the phone manufacturers standard headphones, manufacturers may want to protect themselves. Expected standard for headphones