TubeNet

My studies in this issue have revealed a trend. This is by no means scientific but these are the things that have seemed to work for me.

I don't think a shallower cup will be the answer. The 7B you're currently using is a relatively small mouthpiece. It is also a funnel shaped cup and you might try something that is bowl shaped in the cup. Perhaps a Schilke 69C4. I only suggest this if you're unhappy with the sound or the response, I don't believe this will bring the overall pitch of the horn up.

For raising the pitch, I would try a different backbore. My search has led me to believe that it is the backbore of the mouthpiece that best controls pitch. Specifically, I would try something with a bit larger backbore. Perhaps someone like Doug Elliott could piece together a mouthpiece with the appropriate rim, cup, and backbore that would match you and your horn best. The formula I always follow is:

rim = comfort
cup = sound
backbore = intonation

As always there are exceptions but this approach seems to work for me. Best of luck to you!

My opinion for what it's worth..

I vote for cutting down the horn -- POSSIBLY.

When others play it in tune, do they need to pull out the tuning slide a bit to make it in tune, or can they play in tune with the slide all the way in? Do they use the same mouthpiece, or at least something similar?

Are the main slides on their own instruments pulled out farther than on yours?

If one of your friends can play both his tuba & yours at the same, in-tune pitch, but the slide on his is over an inch further out than on yours, I'd examine the possibility of cutting out some tubing to bring it up to pitch.

Yes, it's an ebay special, but that means you won't be hacking up some special, glowing tuba brand that everyone worships.

You could also try shaving the shank of your mouthpiece so that it goes farther into the receiver. You can shorten most tuba mouthpieces by as much as one inch in that way. Just wrap some leather around the rim, mount it in a lathe chuck, file away while it is spinning, and trim off the end. Stop periodically for test fitting. Try it first with an old mouthpiece, not your favorite one, and see if it solves your problem.

wbryan6 wrote:I am possibly in need of a mouthpiece which will accomodate my horn. I am currently playing on a 3/4 no name, Ebay-deal C with a good sound, but which continually reads close to 20 cents flat. I am able to lip the pitch close to correct, but others who have played the horn do not have the same troubles. My lesson teacher recommended looking for a mouthpiece which might make tuning the horn easier. I am currently playing on a gold plated Conn Helleberg 7B. Which direction should I go from here, deeper or shallower cup? wider or narrower throat? Please leave any feedback you have.

Try a mouthpiece with a more open throat. This should step you up more. Take a look at something like the Yamaha Canadian Brass Replica. It is a Medium trait with Helleberg flat rim but a very open throat @ 8.55mm It is also a good economically priced mouthpiece as well. It works the best for me on my 3/4 F.

Here is what many guides say about throat size:
Throat
Large: Increases blowing freedom, volume, tone; sharpens high register (largest sizes also sharpen low register).
Small: Increases resistance, endurance, brilliance; flattens high register.

These seems to be the given facts of your situation:

The pitch of your instrument is constantly 20 cent flat when you play with a good sound.

Others can play the instrument on the correct pitch.

Jay Bertolet has interesting points of view:

“rim = comfort
cup = sound
backbore = intonationâ€