The COP to me sounds like the worst headphone Beyer has made regarding the mid-frequencies. Very recessed, distant and not very energetic. It's bassy, which is it's strongest point. And easy to drive. Also built pretty rugged. The treble is rolled off too, it's not bright like most Beyers. To me, it's not a good sounding headphone unless you just want to hear bass drops and nothing else. I wanted to like it, when I bought mine, but it was just not salvagable even after I changed pads and everything. Requires equalization to sound right to me. The DT250 is frankly better in my eyes. As is the standard DT770.