I think I found an alternative to just playing noise or sine waves to burn in those headphone things. For best results (for me), I'll just play orchestral tracks for extended periods of time. Those ones feature all the frequencies and details, and if recorded and mixed well, provide perfect burn-in material.
That is actually what I have been doing to be honest, I was going to be using the London Philharmonic Orchestra, which is a great orchestra group that covers a lot of classic songs and bands like Pink Floyd and Led Zeppelin, but then also video game music like Elder scrolls etc. I actually say check them out because they have a lot of unique music and noise. I do not know how well it will help the burn in process, but I will let every one know if I see a difference. Getting the new phones tomorrow noon time.