Try to shelf up the treble region that you like and then drop the hurting frequencys as much as you need.
Although a combination of pad swap, a -1 or -2 db treble shelf and even changing your source will help reduce that sharpness all the better.
What I did when I owned them was use a chifi tube buffer with treble knob, or a schiit loki reduced the 9k annoyance more than software eq for me. (More like reduced the spike less than eq but with better overall sounds, if its very sibilant you may need to change cans)