I have used one day. I 'm really not able to use it longer because it is rotten. I wanted to test AKG headphones in this price range but it has to reconnatre it is hard to find a headphone that resembles the Apex HP60 that I use for 3 years. A deprecated! For 30 euros is Better Apex HP60. Even if it is a semi-closed headphones do not isolate the K77 better and is not worthy of a closed headphone. I tested the headphones with the sounds that I know the voices are not audible enough, it lacks bass ... I have not found a frquence o makes up the headphone. May be that my ears taient HS Lorqui I test. Anyway no one can deny making too plastic.