[yavormoskov]

I just got Amperior, but the left cup where is the short cable moves basically on its own up or down. There is almost no resistance where the plastic strip goes trough the cup. The other cup moves easily up and down but is no loose at all and stays firmly on my head. The other cup adjust itself on my head. Is it normal? Have you experienced something like this? What is a possible solution? 

 

[moriez]

No, that's not normal. Had it happen to the HD-25 myself. I recommend contacting the seller and get a replacement. If possible ask to test your new pair before it's being shipped to you.