and trying with cd quality audio? from my recollection (using a bose qc 25 in passive mode) from my first setup it changed it a little but i cannot describe it nowadays, i concluded the difference was "better" and kept it for (too?) many years now. funny thing i do remember was adding AutoEQ in twice - once through APO and once through Peace. but i notice it now more when im not listening via my headset, its subtle.

sounds like a win though on the Koss KSC75 regardless though, just makes em more portable to other devices for you