I am currently a college student that has played with an open embouchure for quite a while now. However, I have begun experimenting with a closed setting, due to potential gains in flexibility, decreased mouthpiece pressure, and, of course, a better range. This is due to my troubles over the years with developing a quick flexibility, and problems with extending my range above high F without excessive pressure or ridiculous horn pivot.
I will note that for the early stages (it has been a couple days since I've begun) my flexibility has increased with the help of lip compression, I have more dynamic/tonal control, and mouthpiece pressure no longer does much for me (helps me resist the urge to use it, haha). I still have facility of my open setting, as well, but my tone on the closed setting seems very similar, so there seems to be not much need...however...
I know it may be early to be concerned, but I have noticed that it is very difficult for me to articulate above a top line F with this setting, and in fact my usable range has decreased considerably (although I realize that it may be due to new muscle involvement). Also, I'll on occasion get a crackling response from my horn when I attempt to play in the range of 4th line D to that F at a soft dynamic -- I'm required to use much air in order to get a pure tone. However, this increase in air usage also seems to aid in attaining the higher notes (which seems contradictory --- shouldn't a smaller aperture facilitate high range?)
I was just wondering if anyone had any ideas as to what I could improve in continuing my transference to this new setting. I have been doing my best to follow Pops' advice that I can find on the forums, but I feel I need feedback that is more specific to my situation. Thanks!