A vote for burson conductor 3 reference. Excellent with Arya Stealth with metal music. I only add a slight bass boost but if the song has prominent bass it won't need it (e.g. modern Opeth).
Do you feel like you need to turn the treble down? Does Burson smooth it out? For example, I tried some Iron Maiden, and could not listen to it due to piercing treble and sibilance - track 'Moonchild' from Seventh Son (but this is due to really poor performance of ifi Zen). Does the treble get under control with Burson?