This time I wanted to offer realistic sound samples for all the IEMs shown, unfortunately it's not that easy to get reliable results. Using the Free Pro 2 with my reference tuning as base, all the other IEMs should more or less sound like themselves when listened over the Free Pro 2. While this worked for the major part of the IEMs I recorded here, I coudln't get any decent result for the Nothing Ear 1, also the Apple Airpods Pro needed an additional correction, which I quickly applied by ear to get a result which was more similar to what I was actually hearing in real life.
The measuring couplers obviously lack precision and consistency among different IEMs, which makes it close to impossible to get valid sound samples from different IEMs. I will try to do further experiments in future to see if I can at least manage usable results for at least the most important IEMs I own.
I also remember someone having posted a comment about the Airpods Pro some time ago suggesting an app which should allow you to import your hearing profiles and edit them, to be used as a more flexible sound correction for the Airpods Pros (and other Apple headphones too). If you know this app, or if you can still find the comment somewhere, I would love to take a look at the app and try improving the sound of the Airpods Pro if possible. Thanks!