hi , I'm new here and I want to get to upgrade to better headphones , currently I'm undecided between the hifiman he4xx , sennheiser hd6xx and the beyerdynamic dt990 pro , I'm currently not planning on purchasing an amp , I'm a heavy user , mainly watching very HQ media on my phone and laptop for long periods of time , I currently have closed back headphones , I have never listened to open back ones , I care mainly about the sound , and the like 10% about comfort , but I'll prefer headphones that sound the best rather than the most comfortable. thanks in advance.(btw , I'm from Israel).