[xxAMAROKxx]

Pre- over sampling DACs have a steep high end roll off. My guess is your headphones have a spike in the upper range and the roll off tames it.

Looks like I have bat ears.
Why can't I hear Post (or Pre) Echo? I can hear clearly that Pre Echo makes bass intrusive and Post Echo artificial treble.
Are those filters with echoes intended for listening to headphones/earphone at all?