Open low B-flat still flat with slide all the way in

[doublebuzzing]

I have an old Cerveny tuba and it's a lovely sounding tuba but has some intonation quirks. The B-flat below the staff is usually about 20 cents flat with the tuning slide all the way in. The next open F, Bb above that, next F, and Bb on the top of the staff are all pretty much in tune (or within 5 cents) with the slide all the way in. Anyone know the reason this might happen? Lipping that note makes it sound thin.

[Donn]

Is there a good clear note there, but just flat, or is it kind of vague and dull? Not that I have any answers, I just had a baritone at one time with the latter problem; I understand it was likely a leak, but I couldn't find it nor could the repairman I took it to.

[doublebuzzing]

It's a clear note but just not in tune. I did find out today that a shallower mouthpiece does bring it up just a little.

[imperialbari]

A mouthpiece that slots less rigidly may be helpful.

The cylindrical part of the throat should be as short as possible, down to non-existent.

The backbore should be what I call candle-shaped. Denis Wick calls it barrel-shaped. Same thing.

I prefer these features combined with a wide and deep cup.

The downside of this type of mouthpiece is that you are left totally responsible for the intonation. When you have a high degree of control, you have to exercise that control, or the pitch will be all over the place.

Klaus

[TheGoyWonder]

The kaiser-size ones are known to do that.

[doublebuzzing]

A mouthpiece that slots less rigidly may be helpful.

The cylindrical part of the throat should be as short as possible, down to non-existent.

The backbore should be what I call candle-shaped. Denis Wick calls it barrel-shaped. Same thing.

I prefer these features combined with a wide and deep cup.

The downside of this type of mouthpiece is that you are left totally responsible for the intonation. When you have a high degree of control, you have to exercise that control, or the pitch will be all over the place.

Klaus

Do you have a few examples of that type of mouthpiece?

[imperialbari]

PT-50 in two samples, where I have opened up the backbore. More on the older one than on the newer one. I invariably use the old one.

Same with the Yamaha Yeo Signature for bassbone and euph, where I also have opened up the backbore. I later on bought the Yamaha replica of the same model to check whether I had overdone the opening. Again I invariably prefer the old one, even if I have opened up the new one somewhat also. And this is not because I prefer the gold plated surface of the old one, as I actually prefer the silver plated surface.

Klaus

[Mike-Johnson-Custom]

Which model is it.
Many of the Cerveny instruments seem to have a wide octave between 2nd and 4th harmonic. However they have a very wide slot and its easy to correct if you have a strong embouchure. As mentioned above, If your previous instrument had a sharp 2nd harmonic, then it's a matter of retraining your chops. A good friend of mine has had a Yamayork for 10 years now. He finds he pulls slides now a lot less than in the early years.
I have a Cerveny CBB 693. I tune it to the low 2nd harmonic and pull down the sharp 4th harmonic because the slots are wide enough to do that with a good sound

[doublebuzzing]

It's called a Symphonia--not a common model.