How loud is loud?

Seems like a rhetorical question, but I'm curious what other folks think is "ok, now that's loud"

For me, if something's hitting 100dB as measured from where I'm seated while listening, and not just for a brief moments, but with some regularity, that's loud.

I used to listen at higher average volume than I do these days. Typically, I'm finding that at the right volume, the recording is more nuanced then when it's running full throttle.

If I'm not mistaken, the late Peter Walker observed that every recording has it's one correct or optimum playback level. I think generally he was correct, though once we are willing to forge optimum there's a range of acceptable.