Pedal C

You could literally go on forever trying new places until you sound good. Any new place is not going to be "trained," if you will, to play the trumpet. It's an unnatural act to blow into a tube, buzz our lips and sound great, so it takes time for the chops to learn how to sound good. There are lots of great teachers who can give you exercizes to do that will train the chops without your concious knowledge of exactly what the lips are doing, so the only advice I can give to seek one out. Most often a change to the chops will result in some losses before the eventual gains.

Many times a "change" isn't even needed as the right teacher can "evolve" an ineffiecent embouchure into a functional one without having to restart. Again, consulting a great teacher in person is the way to go...

Changing you embouchure without continued guidance is kind of like performing surgery on yourself. Not the easiest thing to do and not usually successful.
Good luck!

Jason.

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"The oboe's A is to make sure we still play it 1 and 2" - Bud Herseth

"One way or another, every patient stops bleeding." - Scrubs