Without a Doubt it is the difference of humans hearing various frequencies at low volume, as documented by Fletcher Munson.
The biggest difference a LOUDNESS (stupid name for a low volume listening adjustment) is boosting the BASS. That is what maintains involvement, keeps low volume from becoming background music.
Tone control, boost bass some should perk things up.
Lots of modern equipment omit tone controls, most omit 'loudness' eq circuits.
The Chase RLC-1 Remote Line Controller unit I mention tooooo often, has an automatic and progressive Fletcher Munson curve that begins at low volume, and increases progressively as you further lower the volume.
you can download manual from hifiengine
https://www.hifiengine.com/manual_library/chase-technologies/rlc-1.shtml
this one is ridiculously overpriced, but it shows the unit well. They pop up occasionally for around $100.
You need the remote, no controls are on the unit.