Lowering pitch

[Erik_Sweden]

Based on Klaus post I get following result:
For a 440 Hz main tuning slide with a extra lenght of 40 mm (20 mm pull) I get following needed slide pulls:
1st: 1.3 mm
2nd: 1.2 mm
3rd: 1.4 mm
4th: 1.6 mm

[imperialbari]

Based on Klaus post I get following result:
For a 440 Hz main tuning slide with a extra lenght of 40 mm (20 mm pull) I get following needed slide pulls:
1st: 1.3 mm
2nd: 1.2 mm
3rd: 1.4 mm
4th: 1.6 mm

Aside from the length for the 2nd valve those numbers obviously are wrong and don’t represent an understanding of the formula I set up. That formula expresses the math behind the equal temperature tuning system. High 2 means ’i 2. potens’ in my language.

With 3 spaces behin the dot the pulling lengths are:

1st: 1.189 mm
2nd: 2.449 mm
3rd: 3.784 mm
4th: 6.697 mm

The dimensions may, at least for the 1st, 3rd, and 4th valves, be checked by the equalent Pythagorean pulls, which would be 1/8, 1/5, and ⅓ respectively of the main tuning additional pull of 20mm.

Klaus

[Matt Walters]

Based on Klaus post I get following result:
For a 440 Hz main tuning slide with a extra lenght of 40 mm (20 mm pull) I get following needed slide pulls:
1st: 1.3 mm
2nd: 1.2 mm
3rd: 1.4 mm
4th: 1.6 mm

Combined with:

You have factory settings? Is the inner slide marked with a scratch ring or something? That's very interesting, I just didn't know there was such a thing.

Miraphone designs their tubas so that SOME slide pull is needed on all the slides to get the horn "tuned up". The advantage of having a slide such as the easy to reach 1st valve slide out a bit for most notes, means that you can push the slide in while playing to raise the pitch of some flat notes to bring them in-tune.

Since even the artist who helped them designed that particular tuba never feels the same two days in a row and never has the exact same environmental situation to play in two days in a row, at some point a real person has to..................

ADJUST THE SLIDES A BIT AND THEN PLAY THE D**N THING TO THE BEST OF THEIR ABILITY THAT DAY.

Set your main tuning slide so that the Bb's are in tune.
Set your second slide so that "A's" are in tune or 2-3 cents flat.
Set your 1st slide so that "Eb's" are in tune. Check the "Ab's" and decide to personal taste if you want to set the slides so that you split the difference.
Set your 3rd slide so that the "Db's" played 2&3 are in tune. You'll play more Db's than Gb's.
Set the 4th slide so that the "C" below the staff is in-tune.

After you set up a 4 valve BBb tuba like I suggest above, you are ready to "man-up" and play it. Now you can compare your mouthpieces to see which gets you the most (warm fuzzy feelings, sound, good intonation, compliments, sweet smelling beath, etc.) whatever you are looking for.

There is no math formula that will bypass the fact humans can screw up anything.

[Erik_Sweden]

You are correct Klaus. I hade my serie: 2^(1/12), 2^(1/11)... but correct is 2^(1/12), 2^(2/12)... I also had 4th as 4 semi tones but it is of course 5

You are also correct Matt. In the end it up to my playing. I was just curios about the theoretical pull

[swillafew]

Hello Erik,
Matt's answer is the science you are seeking. Comments in this thread are in basic agreement, apart from the choice of terms used to describe it.
As for the science of pitch: You are blowing into something cooler than you are. The pitch is changing every time your breath warms the instrument (constantly).

A research scientist I know plays horn and gave me an elegant description of the temperature effect. Still, not a person says, "let's tune, who has the thermometer?". Or, "who has the ruler?"

[Donn]

A research scientist I know plays horn and gave me an elegant description of the temperature effect.

Since I just happened across this recently - The Effect of Temperature Changes on a Brass Instrument, thanks to Art Hovey. I'm going to assume that it's valid.

I don't think any of this really addresses the point, though. He was not looking for a way to play his tuba better in tune. He is concerned with this aspect of his mouthpiece selection, though, and while evaluating the mouthpieces he wants to return the tuba to a "vanilla" tuning that ought to play in tune under ideal conditions. That way he can recognize the ideal mouthpiece when it comes along. You don't have to agree that this is worth thinking about, but that's the idea, as I understand it.

[swillafew]

I don't think any of this really addresses the point, though

The one who addresses the question is Matt. The question in the post is "how far should the slides be pulled to match the main slide". The answer is, start pulling and see what works. It's not an equation, it's a horn that is changing from moment to moment, the air inside not even being equal temperature from one end to the other. As musicians we function without the math.

[Donn]

As musicians we function without the math.

I don't think Erik intends to use math to play, either, but it applies fairly well to what he was trying to do.

[iiipopes]

Hell, everybody is overthinking this: pull the 2nd valve slide a hair. Pull the 1st valve slide two hairs or a smidgen Actually, pull it so Eb and Ab are in tune. If 3rd space C is flat, figure out how flat and have the outer tubes shortened this amount so that you can push for C and leave it out a proper amount for Eb and Ab. Pull the 3rd valve slide 3 about half what the tuning slide needs to be pulled out to tune to 440 at room temperature. the 4th valve slide is probably too short anyway and needs to be pulled a significant amount, whether 440 or 443.

On all the tubas I have played, everything has needed to be pulled, from a hair to almost the length of the adjustment, whatever pitch was being played. This is especially so on 3-valve instruments, where 3rd has to be pulled to get 2+3 in tune, or play a hair flat, so 1+3 is lippable, if the 1st can't be pulled.