Use these straight from DAP leave me wanting more on vocals presentation.
It would be nice if the vocal take center stage, and bit more upfront. I mean, vocal is a bit laid back for my taste as it's not projected like my home rigs and don't have proper height. On tones, male voice lack "sweetness" and organic feel (dry). Woman voice at times suffered mild sibilance and thinness(rare, but still there). Other areas is top notch. This impression was based on my times comparing these with my home rigs. I'm not bashing Z1R as I have compared it extensively with HD800S,LCD-X and Mad Dog using same setup, and these also lacking at that area(with varying degree, ofcourse).
It could be DAP which doesn't have enough juice and silver-coated copper cable. i think we have owner here driven his Z1R using OTL. How better you think compared when feed directly via DAPs, smartphone? i believe in cables, i think gold-plated silver could sweeten this up.