My experience involved using a Sennheiser HD700 and a Parrot Zik 3.0 headphone with all kinds of music.   Headphones plugged into the X7: The HD700, and Zic 3.0 have sounds that are completely different on the X7.  The HD700 sounds excellent with perfectly layered, robotic,  precision sound, while the Parrot is a little wilder sounding on the X7.  The Parrot looses musicality because of the fun it has with low bass, elevated highs, etc.  I think the Parrot is more fun with the X7 when you just want to hear the party and not necessarily the...