[hestipod]

I find the lowest settings on any phone I have tried too loud with any headphones or bluetooth device. I gave up trying. Even in a normal room its painfully loud. Per your username I do have tinnitus also and some minor hearing loss but not massive. No idea why this is so miserable.

[seemack]

I had a similar issue where I bought a pair of in-ear monitors with very low impedance and the lowest settings on my phone/laptop is still too loud. I solved it buying a small headphone amp: https://www.radsone.com/earstudio

It's worked out really well. It's much smaller than most headphone amps and has the added bonus (for me) of making my headphones wireless.

[LeoTinnitus]

I currently use Music Volume EQ for android and it works. It's annoying sometimes cause I may need to restart every once in a while or reinstall it, but it allows me to turn the equalizer at the lowest level, turn it on, and then listen to that base "quiet" as the new lowest level.