Ember-hifi how to set header to request

I try to use ember-hifi. It works grate from the local store. But i have troubles to play sound from server. My server demands auth header to be present. And the url looks like http://ift.tt/2Dbgr9f. When i send get request, the server return file that can be of mp3 or wav. But i do not know the format before get it. That way i get warning about mime type. But if hifi service try to get record from server the conection refused because there is no auth header in request. How to add header to requests from addon? I do not understand what options i can set to play method.