Electronic – TRRS connector with iphone circuit board, how to get mic compatible with PC input (Bose Q25)

iphone

I have a Bose Q25 headset, it uses an iphone compatible trrs jack.
It contains stereo input, mic output and the button controls.

I split it into 2xTRS jacks using a commercial splitter, the mic is still disfunctional.
I tried to contact Bose support and asked them how to connect it to the PC.
Their answer:

Due to the fact that Bose Corporation is a privately held company, we
consider the information that you have requested to be proprietary in
nature.

That's absolutely ridiculous, as if the iphone connector standard would be a proprietary secret. There are hundreds of companies making such connectors/headsets.

However, I am not familiar with it.
Does anyone here have any knowledge how the mic is connected, what sort of circuit would be required to get it compatible with PC input? (either line in or active mic)

I have a standard TRRS headset without buttons (just mic and speakers), that one works flawless. So the button circuit board does something that needs to be taken into account.
It can not be a big thing as all the smart phones (Android as well) can interface with it.

Maybe it's just polarity (I don't want to risk damaging the 300€ headset) or some simple circuit I have to apply to the connector to get the mic through.
Anyone ?

P.S.
As I found Boses answer to be very customer disrespectful (I did not ask for a schematic or the DSP programming..) I would like to keep this question updated until I have it solved so other people can benefit from the information.

Best Answer

Here is an in depth explanation of jack pinouts http://www.cablechick.com.au/blog/understanding-trrs-and-audio-jacks/

Its super late and im glancing at your problem in my seprate search on a different subject that lead me here but based on what i read from your problem and what that websites says it seems like BOSE swapped the pin locations on the TRRS jack to make it hard for people to use it with anything other than a bose product. One thought I had would be to make your own "adapter" by taking a female TRRS jack from some other bose component (if you dont mind partially screwing it up) and wiring that female jack to a regular male TRRS. Hope this helps man JUST NOTICED I overlooked some info in your post. but im too tired to delet the irrelavent stuff i suggest you take a look at the diagram for an Iphone TRRS on that link i posted i feel like it will answer your problem. let me know how it goes!