Apart from the purpose of having a relatively similar Transparency thus a nice Audio continuity of your headphones,I.E.M's etc .So music produced on one type of headphone will sound reasonably similar on another headphone or I.E.M .That's an issue I have with westone 3's .I'd produce a track using M50's and or HD25's and parts in the lower frequency would sound substantially different on the W3's with some tracks .
Anyway I have no Desire to Argue this particular point. I only mentioned it as to be helpful.
I have found Jokers Interpretation of headphones such as M50's , HD25 and yuin G2a to be Accurate .Not only Accurately describing the Detail of these headphones independently,but also there transparency being relatively well match . HD25 being close to M50's and the clip on yuin G2a having a Transparency that doesn't leave you feeling Disappointed after you've been listening with the Bigger headphones,though the G2a it does need EQ or a tight fit .
CK10 seems to be another Audio device with that Transparency signature .Though with slightly risen Highs which can at first listen veil the sub bass region .
So merely as a helpful suggestion for people whom feel CK10's are too sibilant ,Try turning down the High end Frequencies spectrum /Treble .Then you can turn the volume up more to hear the bass without the highs sounding Sibilant .
I'm trying this method out just to see if I can recalibrate my ears.Maybe using westone 3's I've become too used to the bass being in my face .
But if after a few days I still feel that the CK10's are too Sibilant .....?
Moving on