...after assuming I've always been a downstream player. Over the past few years and many trumpet teachers, I've undergone changes ranging from air support to rebuilding my embouchure by moving from the side more to the center (horizontally) and positioning 50/50 vertically, where as before (while in high school) I was predominately 1/3 upper, 2/3 lower. I've been cursed with endurance issues, unreliable upper register...the list is endless. Recently I decided not to seek professional instruction after 5 different teachers couldn't really help my issue. Nearly every one suggested the time old answer (More air, blah, blah) and I assure you, I'm putting more than enough air into the horn. My issue is I don't think I'm directing the air right. I get up to F# at the top of the staff and bam, my lips stop vibrating. So my question is this: Would me setting up to play downstream even though I'm an upstream player cause these problems? Or is there a remedy for this that I'm overlooking? I'm in my third year of college, about to transfer to a 4 year university and I really need to figure out a course of action before it's too late. Musically, I can understand how pieces that I'm performing should sound. It seems that physically, I'm being held back. Any suggestions? I'd appreciate any input.