[sandy1010]

does any such product exist?

Virtually every pair I’ve heard maxes out at a pretty tepid volume.

Would love a recommendation.

 

[ProtegeManiac]

does any such product exist?
Virtually every pair I’ve heard maxes out at a pretty tepid volume.
Would love a recommendation.

I wouldn't bet on complete systems out of the box being able to do that. As much as they go with high efficiency drivers and you have decent enough isolation, there's just barely any space for an amp circuit on those (even the ones that have what looks like a remote on the cable that goes around the head connecting the earbuds) let alone a battery.

Best option for you is to get any IEM with 100dB/1mW++ sensitivity and use it with the Fiio BTR1. Clip it to your collar or something, then just manage the cables, gut a section of it and reinstall a new, compact 3.5mm plug, or use a short IEM cable. Fiio is supposed to come up with a few short cables to make the BTR1 easier to use (ie less cable slack) but chances are it might be MMCX (or at least initially) so, if anything, might be safe to pick an IEM that has MMCX.