Obviously I don't relax the mouth muscles involved to play on the right harmonics.
I felt for the first time after years of playing brass instruments that the skull can "resonate", I think because of the pressure not totally channeled throught the airstream but pulsing the most on eyes and also on all head.
I'm feeling less stress but no totally stability on the air.
Do you think is a wrong approach?
I would like to remove stress from my playing but maybe this is too much Yogi

Have you ever tried?