Some two weeks ago I got a pair of Beyerdynamics DT770s. They seemed okay for a while but they developed a crackle in the right driver after two days or so, which would play no matter what audio sample. I sent them back (Amazon) and got a new pair, and these ones have a crackle/pop in the left driver; (I've only noticed this for this wiring test so far).
Should I send them back again and try again? Is beyerdynamics QC really that bad or have I just been extremely unlucky? What other closed-backs could I look into (at a similar price and frequency response)?