I am going to audition on both the Eb and Bb clarinet. I was wondering if anyone had any tips on how i can improve on the Eb [i can play on the Bb perfectly fine]. Anything higher than a high C will not come out.

thanks

Have you already had the audition yet because mine is a week away. If not, i'll get this really good guy in my section (that is trying out on E flat) to post here under my account or something.

Could be a number of problems. Please post what equipment you're playing on. Reed, reed strength, mouthpiece, and lastly ... what kind of horn are you playing. Any flaws on the mouthpiece table or tip can destroy your chances of sounding good on Eb. Also, a reed that is too soft will tend to stop on you in the upper register. Try taking more mouthpiece, or raising your reed a bit. Make sure the reed isn't warped at all. If it is, then flatten it. One more thing... there are tons of crappy Eb mouthpieces out there made by companies who make student-quality horns. Make sure you have a top-line mouthpiece if you want success. Good luck on your auditions!

my audition is in 3 weeks

Great! Even though you've already gotten help, I'll get him on here. You're so lucky to get more time.