Pissssssssssssh those sissy HE-500 ain't got no bass. You need some real BASS cans/ iems that has amble amounts but also have crazy nice mids/ highs. The ATH WS99s, JVC FXZ200s and the gr07 BEs all have this and then some. I WANT IT ALL cuz i am a greedy bastard!!! But your H-500s probably has a Sh!T load more soundstage though.
Those Philips X1s might be more of my liking than Hifimans offerings. But not ready for serious open cans like those just yet.