[majkel]

You don't need a better source than Yamaha Piano Craft mini hifi system ro realize differences between HD555 nad HD595. That was the exact way of choosing the headphones in my case. HD555 fall short when compared to HD595 on aggresive music with lots of instruments like nu metal for instance. First - HD595 bass goes lower, second - HD555's midrange gets smeared and loses resolution while HD595s stay cool and articulate all instruments precisely. The last thing, porbably due to midrange flaws in HD555's are clearer and better pronounced trebles. For me, even moderately amped HD595's are at least one class higher than 555's.