I already did that, I bought the gear and Measured, and it says 600 ohms, checked out, so now Beyerdynamic has this 600 ohms with no label...
Please help me im worried, I started by testing my headphones with a 200 Ohm test and they started to sound like popping a bit, then I though this was making damage to my headphones, and tried with a bit more 2000hz because I tough 200 could be not enough power demanding and that the cause of them to dont work and popping and not measuring the ohms correctly ... they are kinda 577 ohms with this last DCR test... but Im worried, I think they are not sounding the same after this, I just bought them a couple of days ago