Latest Oneodio Wired Headphones Monitor 80 Hi-Res Almost Unused

Open-back monitor headphones.
They sounded great when I tried them, but at home, they lacked impact, and I had to listen at maximum volume.
I found out that they don't perform to their full potential unless the input impedance is 250Ω or higher.
I considered buying an amplifier but decided to sell them instead. (I later found out that some USB Type-C DACs can output up to 300Ω.)
Still, I listened to them a few times with music apps on my smartphone, and the individual instrument sounds and vocal breaths were so clear it gave me chills. Despite being open-back, the bass is also sufficient.
Music I previously thought was good sounded very amateurish in comparison, as if I had been deceived. This headphone reveals both the good and bad aspects of a song.
Therefore, I believe these are recommended for those who understand.
The accessories are shown in the photos and include:
3.5mm to 3.5mm cable
3.5mm to 6.35mm cable
Carrying case
The box and manual are not included.