| Jorge,
I'm afraid to answer without hearing you, but it sounds like you need more milage on your embouchure change (?) Long tones, flow studies, and countless, patient, hours might do the trick. Once you're making a clear, easy, sound in all registers you simply articulate it.
Which leads me to a point (forgive the generalization for a moment). Often a problem that surfaces in our fundamental technique is caused by something else preceeding it. Remember to balance flow & focus. Easy to say, hard to achieve.
Cheers,
EC |