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I'm trying to gain a better understanding of the effect of bore size on the sound and playing characteristics of various horns.

Logic tells me that a smaller bore would take less air, but maybe have a less open (or--glass half-full--more focused) sound, yet I read that many large-bore horns are easy to play/not needing much air.

Obversely, I know that there are smaller bore horns with broad, orchestral sound.

What gives?

Is bore even something to consider in looking at horns? Do other design elements dictate the bore?

I've had trouble finding much on this topic by searching here and elsewhere on the web. Comments by folks who really know something about this valued over anecdotal information. Thanks.

The bore has very little to do with the performance of a tuba. The overall taper, especially from mouthpiece receiver to the valves, then the bore, plays a much bigger role. A 4 foot leadpipe into a .821 bore will brobably be stuffy. A 1 foot leadpipe into a .625 will probabably be fairly open.

J.c.S.

The way I think I understand it, bore has a much more DIRECT effect on the instruments where the cylindrical portion makes up a larger proportion of the horn (trombones, old-style trumpets, and even a great deal of the cornets we now call trumpets... ). And if the cylindrical portion is larger, things are easier to compare one to another, like size.

As mentioned, it's the overall bore profile that make a tuba sing. Does "the bore" of one section of a tuba matter? Just look at the different places in the "bugle" that the valves of a piston valve tuba occur as opposed to a rotary tuba.

A good tuba looks an awful lot more like a flugelhorn than it does a trumpet or trombone. And even trumpet gearheads rarely talk about their flugelhorn's "bore"...

circusboy wrote:Is bore even something to consider in looking at horns? Do other design elements dictate the bore?

No. Tubas are a system, and all parts have to work compatibly with each other to get a positive result. A King 2341 with a .679 bore blows as open as most instruments with a larger bore, for example.

Yes, other design elements dictate the bore. You have the diameter of the leadpipe at the mouthpiece receiver (less than a half inch) and the diameter of the bell throat 18 feet away. The instrument tapers between the two according to a taper design. That taper design affects the overtones and intonation of the instrument--the conical taper is grossly complicating compared to straight tubing.

The valve bore has to be what it has to be at a point where it can be inserted into the bugle. Because rotary tubas feed the bugle tubing through the valves on the left side of the instrument and the player is on the right side, the leadpipe tends to be rather long. That pushes the valves to a later (and bigger) position in the taper design, and thus the bore is bigger.

Bore is, at best, a surrogate measure for the overall size of the instrument, but even then only within a narrow configuration category. My Holton has a .750 bore, which is a large bore for a front-action piston tuba. My Miraphone has a .770 bore, which is merely medium-sized for a rotary tuba.

If I see a picture of a tuba and know that it has a .750 bore, and another similar looking tuba that has a bore of .656, I can guess the first tuba is quite a bit bigger. For example, my York Master is similar looking in general configuration to a Conn 5J. I could look at separate pictures of the two and not be able to tell that the York Master is MUCH bigger than the Conn. But knowing that the YM has a bore of .750 and the Conn has a bore of .656, I can relate the two. But using bore is not even as descriptive as the quarter size system.

Evaluate instruments on the basis of what comes out of the bell in relation to what you put into the mouthpiece. Choose on that basis. Take the bore that comes with it.

Rick "who has played some really stuffy tubas with really large valve tubing" Denney

the mouthpipe taper will play a big roll in how the horn blows also. A quick taper will be freer blowing,but it won't "slot" as well, and there will be more wiggle room on each note. A long taper will slot great and have great response in the mid range but won't be as free blowing.

The thing I don't like about small-bore tubas (under 0.700") is the way the resistance changes as you put down more valves. I like to feel some resistance, but I don't want it to change while I am playing, and I don't want my tuba to fight back at me when I want to "nail" a low note. For that reason I think the resistance should be in the mouthpiece and leadpipe, not in the valve section. I really like the Nirschl valve section that I grafted onto my old Martin BBb (the smaller model) because the 4th valve has extra-large bore, so that the low register is wide open.

A valve trombone and a baritone horn can have the same bore in the valve section, but they sound very different because of the taper or lack of taper in the bugle. The same thing is true of tubas. Fat tubas make fat sounds, and skinny ones make more penetrating sounds.[/i]

windshieldbug wrote:A good tuba looks an awful lot more like a flugelhorn than it does a trumpet or trombone.

I would hope so! (turn the flugelhorn so the bell is pointing up -- makes it easier to see)

Art Hovey wrote:The thing I don't like about small-bore tubas (under 0.700") is the way the resistance changes as you put down more valves.

Hmmm I'm not so sure it's accurate to state that all "small" bore tubas have this tendency. My Getzen CB-50 (.689") shows no signs of this trait and blows very free regardless of valve combinations. FWIW.