For those who expected that in the wild west everything is unified and standardized ... Already many users mobile phones(smartphones) encountered a headset compatibility issue. Usually complaints go as follows: “It happens that you connect an old headset to a new smartphone, but the microphone does not work and the sound in the headphones is somehow deaf. But if you hold down the “answer” button on the headset remote at the same time, the sound in the headphones becomes much better.” As a result, someone may decide that this headset is defective. But in fact, a specific headset is simply not compatible with a specific smartphone (phone).
Mobile phone headsets with a TRRS ("Jack") plug, developed up to and including 2011, were soldered according to the scheme OMTP(Open Mobile Terminal Platform):
- Ring 2 (Ring2) - Microphone (Mic)
- Base (Sleeve) - General (Gnd)
In 2012, the developers, as they say, got a harness under the tail, and they began to implement the pinout CTIA(Cellular Telephone Industries Association), aka AHJ (American Headset Jack):
- Tip (Tip) - Left channel (Left)
- Ring 1 (Ring1) - Right channel (Right)
- Ring 2 (Ring2) - Common (Gnd)
- Base (Sleeve) - Microphone (Mic)
But in fact, in these wirings, only the contacts of the microphone and the “ground” change places. If you connect a headset with an inappropriate pinout to the device (for example, connect the classic Nokia WH-205 to the iPhone), the sound in the headphones will be noticeably muffled, and it is not a fact that the microphone will work (in the worst case, the device will not detect the headphones at all).
To determine what standard the headset is made to, you need to measure the resistance between the extreme contacts of the TRRS plug (between the tip and the base). If the resistance is about 30 Ohm(headphone impedance), then we are dealing with a good old headset OMTP. If we see cliff, and when you press the button on the remote control, our 30 Ohms appear, which means we have a new headset CTIA.
What to do?
To ensure the compatibility of devices and headsets of different standards, there are adapters " CTIA and OMTP headphone converter», "miniJack-miniJack FiiO", "FiiO LU1/LU2" etc... The beauty is that this adapter converts both CTIA to OMTP and OMTP to CTIA. It's nice that some manufacturers carefully complete their headsets with such adapters. An example is Ergo VM-901, Jabra RHYTHM, Philips SHE3595 headsets.
But other people do not bother with such "nonsense" at all. They have different tasks and priorities. For example, they (people with other priorities) may be important and demand the sale of real estate in Ivano-Frankivsk! Since Ivano-Frankivsk has established good conditions for people's lives and businesses. And if you want to settle in this city, you may need real estate. In short, you understand who has what priorities ...
You will laugh but...
As it turns out, the variety of headphone pinouts is not limited to the two above standards - CTIA and OMTP. And that's half the problem. And alas, the tragedy of the incompatibility of the gadget and the headset is not limited to the pinout alone. There are many headsets on the market with circuit bells and whistles, “thanks to” which even a compatible (in terms of pinout) headset may not be recognized by your smartphone. In this case, the headset at best will perform the functions of headphones.
If a gadget (for example, some kind of android phone) do not support multi-button headset, then no adapter and no soldering of this headset (for example, from an iPhone) will allow you to use the convenience of the “Rewind”, “Volume”, etc. buttons. In this sense, the alteration of just simple one-button headsets, in which between the 3rd and 4th contacts there is only a microphone, a button and a capacitor, leaves a firm hope.
Well, the last fly in the ointment. In decent headsets, the microphone core (or even the entire cord) is made with a shielded wire, and the common wire (GND) performs the screen functions. Of course, after altering the headset or using an adapter, the common wire becomes a microphone wire, and the microphone wire becomes a common one. Thus, the common wire ceases to function as a screen and the consumer qualities of such a headset are somewhat reduced. Of course, a headset, the cord of which is made with an ordinary wire, cannot be spoiled by such an alteration.