Headphones Bose QuietComfort 35 Problem?

Have a short a question for you.

Namely, I bought the headphones mentioned above today and I'm a new customer in Bose things, so to speak. The headphones were also wireless but I would like to use them with my Mp3 player, so cable was included anyway, the problem now is that they sound extremely quiet and synonymous only on one side, so really terrible as if the things were broken, even if I do not click on loud, nothing like it when I connect it to my laptop, I do something wrong, the connection cables are broken I do not know? I thought plug in and finished…

Plug is probably not quite in it. Firmly squeeze.

Ha! In fact my mistake.