hi guys, i could really use some help here. two particular notes on my Eb clarinet, the high C# and D are very stuffy and resistant. The highest range of the instrument, from the Eb to the F# is fine, so i doubt it's a leak or technical problem. I really need these two notes to be more responsive, and to actually respond. I have tried several alternate fingerings for the notes, )which usually either respond worse, or are really flat), and i dont feel like spending $200 on a fancy-shmancy backun barrel, which might not help at all. any ideas?