Basically I have noticed that if I have the scroll wheel on the back of the right cup turned around 70% up(made up number but somewhere around there) you can slowely hear the left cup volume catch up to the right cup basically making all the background sounds be heared on both sides, but like voices/stronger instruments or honestly most things on the right cup until you reach this threshold where all of a sudden the left cup volume goes way up to be on the same level as the right one.
(this can be done wired or wireless)
so to test it just find a good song that has continues sound with voices prefered. set your computer sounds lower so you can reach the max volumes from the headphones without killing your ears. then go slowly up with the volume on the headphones itself, and somewhere around 70% you can hear the right cup overly being louder than the left one and then like 75% the left one will catch up.
I have contacted support twice, cause i already send back my first pair and got myself from a different store another one, both having exact same issue that can't be just hardware failure as the support has told me