Sorry to all the guys who have been asking for IRS or DDC recently, I haven't been active in this area lately and these days I prefer to have the earphones in question in my hand before trying to correct them.
In some good news though, EVERYONE can have a try of my corrections, thanks to a dollar store pair of earphones that literally anyone should be able to find and afford:
These were hanging around at my local Kmart by the dozens at $2 a pop so I grabbed a pair to try out, and they were expectedly hideous to listen to out of the box. But you should try listening to them with my corrections applied
These may come with one channel wired in reverse relative to the other, so I've made two versions of the corrections, one assuming correct polarity and one assuming reversed relative polarity:
Try on one or the other with these dollar earphones to see which one is right for you