How do you know when you need a bigger mouthpiece?(such as,going from a 6 1/2 to a 5G) Just curious, b/c a band director once told me i needed a 5G but he had never heard me play. Also, what are the advantages of a bigger mouthpiece?

Usually you will need a bigger mouthpiece if the one you are using does not give you good register, mostly on lower pedal tones. If you have a good sond on hight notes, but lower notes sound fuzzy or weak, a bigger mouthpice must be used.

Its like my low notes are ok , my high notes are pretty good. but my middle register(notes that are on the staff) is kind of airy. I guess those are considered the middle register. idk.

Don't worry about the mouthpiece. There isn't that much of a difference between a 6 1/2 and a 5. Worry more about practicing your fundamentals. Do lots of long tones and lip slurs. You problem is probably not the mouthpiece, but that you aren't using enough air. Practice lots of longtones, playing really loud, and then soft with the same amount of air (or more). Also practice a lot with the mouthpiece alone. It could also be a combo of not enough air and also not being properly set on you embochoure and not getting a good centered sound.

Remember, it's rairly the equipment...

darn.lol.
ok..i will deff. do those. And what exactly am I listening for when buzzing with just the mouthpiece?

also not being properly set on you embochoure and not getting a good centered sound.

how do i know if its that or not? Andhow do i fix that?

I personally prefer smaller mouthpieces as I like higher registers. I'm currently using a yamaha 47.
Big mouthpices gives u a better tone, especially for lower register, but will tire you out much faster than a smaller mouthpiece.
Big mouthpieces train your lips too.

You need to get together with a good private teacher to answer your question. Mouthpiece size is a very personal thing.
Everyone gets so worried about how high and low they can play that they often neglect the "money" register.
Like Erik said.. fundementals. Long tones.
PRIVATE LESSONS
honestly.. I can think of a lot of things that could be making your sound airy.. but without seeing or hearing you play, we really can't help.
maybe put up a recording or video of yourself playing?

just out of curiousity....
How far would it be for you to get to UNC Ashville? There is a professor there Dr. David Wilken who is extremely knowledgeable about embouchure types (which does correlate with mpc size choice). If it's not too much of a road trip, maybe you could work out a lesson with him? Another one would be Doug Elliott, but he's based out of Silver Spring, MD.

Just remember - mouthpiece size really has nothing to do with how high or low you can play. I have basically the same range with a bass trombone mouthpiece as I do with a small tenor mouthpiece. Choose the mouthpiece based on what kind of SOUND you're looking for.

Embouchure type does have a lot to do with what sized mouthpiece you use. Many people actually do well on a 3G rim with a shallower cup. I'm one of them. Other people simply should not be using large rims at all, and that's OK too. Some of the major orchestra players in this country use a 5G, others use mouthpieces with rims as large as a 1 1/2G (with a shallower cup, of course). Bottom line is that they all sound good, because they've determined what works well for them, and stuck with it and practiced.

I don't know much about these embouchure types, but you can find some articles on the OTJ archives. The best way to figure out is to take a lesson with one of the guys mentioned above, or if that's not possible, find a good local private teacher.

Also, I laughed at the first post. How could your band director know what mouthpiece you need if he's never heard you play alone? Sounds like he's not a trombone player, and he's just repeating the standard BS that others have told him about "correct" equipment.

Also, I laughed at the first post. How could your band director know what mouthpiece you need if he's never heard you play alone? Sounds like he's not a trombone player, and he's just repeating the standard BS that others have told him about "correct" equipment.

yea. I wondered the same thing. But um...I have a private lesson teacher or w/e. I just haven't been able to ask her b/c she's been out of town. But, I dont want to ask her and she be all like " What in the world are u thinking??" and like blow up at me or something. lol. Im a worry-wart.

Im abt 4 hrs. from Asheville.

Well, if four hours on the road isn't out of the question, consider contacting Dr. Wilken and see if he's willing to see you for a single lesson for mouthpiece advice and an embouchure checkup. If you are considering, it's only good etiquette to talk to your teacher first, but most teachers are fine with it especially if you're going to see someone for a specific issue. I got together with Doug Elliot to help pick my mouthpiece setups and I tell ya, I wouldn't want to play anything else. The right set up FOR YOU can make a huge difference.
Or, wait until March, come to the Eastern Trombone Workshop in Arlington, VA. You'll get to try just about anything you'd want. Plus, Doug Elliott will most likely be there.

We(the band)are going on a spring trip to VA in March. Which would u recommend I do?

I guess it depends on where in VA you are going?