Thought I need to share this. So I tried to play with different tips, none of them really gave me a complete seal. Foam usually gives best result for me on ER2 or my TWS Melomania 1+. However the stock foam on S12 even at its largest size still doesn’t seem to give me a complete seal. So I tried the stock medium white tip with black core, since it still doesn’t give me complete seal, I tried to push it really in, like deep inside my ear canals (almost similar deep like the ER2 but much more comfy) and wow a world of difference, sound stage open up more like holographic, treble tame down a bit since the bass is more present and overall a much warmer sound just to my liking. I guess I need to look for another tips or just keep using the stock and push them deep inside. If you haven’t try this, please try and let me know if that works for you as well. Now I see all the rave and hype about this IEM lol