I initially had my eyes set on the HE-500s but after some research I decided that the sound signature of the HE-400s may suit my tastes better as I predominantly listen to EDM (Tech House, Minimal, Trance, GOA, Psy). Initial impressions out of the box were quite impressive. For those of you who have yet to try a Planar Magnetic headphone - the detail and clarity are something else compared to dynamic headphones. There is no background distortion or noise at any volume as the background remains completely black.   The soundstage is adequately wide...