As a devoted David Clark headset user, I thought the X11 would be the best of the best. I have had DC headsets for over 30 years and currently have four. After using the new headset I determined it was defective. I simply couldn't understand the controllers. It seemed as if the voices in the earpieces were out of sync.
I returned it to David Clark and they changed the left headset and the headset controller. That brought an improvement. Then I read your first evaluation of the headset and I agree it isn't as good as previous Clark headsets. It has weak and muddy audio.
I have since returned to my DC H10-13X. It may not have the comfort of the X11, but I can hear the controllers clearly. My X11 is in the back, in the bag for the passengers if they want one. We have a Bose in the co-pilot seat of our MU-2. I have used it off and on and agree it's very good. I think Clark needs to redo the circuitry and put more soundproofing in the X11.
Kenneth Earl Germantown, Tennessee