According to this Microsoft support article Lumia phones support the AHJ standard, except the Lumia 920 and 820 which also support OMTP.
The article makes no mention of newer models, so I pinged @LumiaHelp on Twitter to check if it's still up-to-date. They confirmed that it is, and that the Lumia 950 supports AHJ headsets.
(Update: unfortunately the @...
The issue here is the impedance difference between your Lumia 525, and the headphones (MDR-AS200).
Lumia 525 jack: 8 Ω speculation, see comments
MDR-AS200: 16 Ω
Your issue is a typical situation where the device that transmit the audio signal over the jack has a lower impedance than the speaker.
This usually results in what you ...
There is nothing more I could think of other than Hard reset.
Have you performed any hard resets after upgrading from 8.1?
As I have seen many users have faced problems after the upgrade which are solved by a Hard reset. Even websites like Windows central, MS power user advised a hard reset after upgrading to W10M for better experience. Note that hard ...
The problem is not the headset as you have mentioned using 3 different headsets. The problem may be in your phones audio jack.
As far as I see any software errors such as turning on battery saver mode will affect playing music via speaker phone also.
The only viable solution may be to take your phone to nearest Service centre.