Have not used or heard a Darkvoice.
Went closed-back with wood cups and Yaxi Alcantara pads. Made it darker sounding, but also more spacious, warmer and fuller sounding, and a better low end presence with smoother sound and same detail. They've pretty much replaced my TH-X00 Purplehearts...subbass master but in a darker, more pleasing sound with better, less fatiguing highs. They do everything well though... vocals are some of my favorite in a headphone (though not as forward as on the Porta Pro with Yaxi pads) and there is no lack of detail in the highs even though they are a little relaxed.
With EQ and on the Garage 1217 Project Ember sounds absolutely beautiful - supposed to be listening to my new Kaldas RR1 but would much rather listen to the HD58X on the Project Ember amp with the JJ Electronic 12BH7-A tube... that amp is something else. I've pretty much decided to eventually sell my Gustard H10 amps after the short time I've spent thusfar with the Ember... I want to try the Garage 1217 Project Polaris before getting rid of them first to see if it will work for some of my other headphones that don't quite like 'tubification' - mainly the DT-177X GO.