So in the end who is the best?
Or King - R10?:)
apples and oranges.
While HE90 and STAX are somewhat comparable, they are both likely to be highly different to the R10, different driver entirely (Electrostat vs dynamic)
Would depend completeley on what sound sig floats your boat.
IMO, speakers (Magnepan comes to mind). But for headphones, to me it's the stax 009s because they have detail that imo trounces speakers in the five and even six figure price range. The orpheus has a nice presentation, great warmth but I find it is outperformed by speakers and doesn't really beat speakers in anything