Greetings, I searched for closed embouchures, hoping this would be covered, but met with more results about mouthpiece placement than formation of embouchure. When I place the mouthpiece against my lips, from what I understand, my lips are to be closed in the "MMM" humming position, then the air forces them open to start the note. However, when I do put the mouthpiece to my lip I tend to keep an opening already made between my lips, so that all I feel is the rim, rather than also feeling the cup. I'm not encountering any problems at all, occasionally I get a double buzz, and my extreme register (extreme for me being high F/G as per Brandenburg) is fairly inconsistent from day to day, but I'm not straining to get those notes when I do. My studio professor has never said anything concerning mouthpiece placement/lip strength for these things so I've not thought much about it. I've just always wondered about open vs. closed lips before playing actually commences. Thanks all!