How to connect wires of headphone correctly?

[Android Central Question]

I have to record internal audio on android without root and no pc. I also watched videos on YouTube. One person showed that cutting and conneting headphone wires can record internal audio. But my headphone has different wires.It has Green, Red, White and red-green(combined) wires. I don't know how to connect that wires.please help me I have one channel on youtube.

 

[Rukbat]

You need some way of determining which wire is which, relative to the plug. The tip is left, the next ring up is right. You want to connect one of the earphone wires (preferably with the phone set to mono, to the mic connection through a capacitor of about 0.1 µf. (The voltage of the capacitor is unimportant - there's only 5 Volts in the phone and you're not going to find a capacitor that can't handle at least 5 times that much.)

But finding the wires ...

You carefully cut away about an inch of the covering of the wires. Then you stick a really thin needle through one at a time, and test continuity to each part of the plug (tip, each ring and shell), and write down which wire connects to the first ring (if you can't get mono, a lot of mono audio is on the right earphone) and the shell. Then carefully melt insulation on the 2 wires you need (mic and right earphone) and connect the capacitor between them. (Don't connect the wires together - there's voltage on the mic wire, and the earphone is an output- you can blow that channel if you feed voltage into it.)

Depending on the level of the audio, the impedance of the audio output and the mic circuit impedance, it may work - or it may not. And that varies by phone, so it may work on that person's, but not on yours.

The most sensible way, but it requires a knowledge of soldering in small places, is to buy a 4 pole plug (like the one on a hands-free earphone) and wire it, and a cheap earphone, together. (The cheap earphone is so that you can hear the sound.)

Or find a friend who's an electronic do-it-yourselfer to do it for you. S/he can just google android earphone schematic - there are hundreds of them on the web.