I would have to agree with you as the added volume control should be left up to the music player.
Well a friend of mine i work with have an old set of PX 100 and seem to be open back. Yea i was looking at the 448s for noise cancelling for train but then thought may aswell play louder and create my own noise cancelling haha

Alright yeah thats a good idea actually how loud should it be played at during the break in period??