True Conical Bore

circusboy · Post by **circusboy** » Thu Apr 13, 2006 1:29 pm

Has anyone ever blown anything like one of these:

http://www.rugs-n-relics.com/brass-phil ... -Tuba.html

This is conical all the way, so no working slides. Obviously, the market has determined that it's not worth the trouble, but . . . .

windshieldbug · Post by **windshieldbug** » Thu Apr 13, 2006 1:47 pm

Not a tuba, but I have a Couturier Conical Bore cornet (just like Phil's, only silver), with the same type of non-adjustable slides. With any mouthpiece (vintage deep 'V' or modern) it plays like, er, well... a cornet.

Later model Couturier horns actually had removable slides. It was pretty much a fad, because unless one uses compensating type valves it's very hard to get a consistant increase in the conical bore and still be able to use valve combinations.

Couturier even had a Conical Bore trombone, which had inserts in the inner slide to keep the bore increasing. Of course, with the slide extended, there was also a lot of cylindrical tubing mixed into the middle of all that...

Chuck(G) · Post by **Chuck(G)** » Thu Apr 13, 2006 4:55 pm

It's not possible to have a uniform continuous concial bore on a valved instrument. Think about it--if the bore is continuously conical for no valves depressed, it can't also be continuously conical with any valves depressed. In fact, even with conical valve branches, the more valves are depressed, the more the valve branches must approximate a cylindrical pipe.

We do have a close relative to the Couturier idea, however--the "graduated bore" where the bore of the 4th and 5th valves is larger than the others.

BTW, Couturier was a cornet soloist with a very interesting career:

http://www.angelfire.com/music2/thecorn ... co-cz.html

iiipopes · Post by **iiipopes** » Thu Apr 13, 2006 5:14 pm

Actually, to our 21st century ears with electronic keyboards and having grown accustomed to equal temperament, we hear the 5th and 7th partials as flat. So, some cylindrical tubing, or at least some steps in the conical tubing, must be engineered in order to make at least the 5th partials acceptable to equal tempered ears.

Chuck(G) · Post by **Chuck(G)** » Thu Apr 13, 2006 5:23 pm

iiipopes wrote:Actually, to our 21st century ears with electronic keyboards and having grown accustomed to equal temperament, we hear the 5th and 7th partials as flat. So, some cylindrical tubing, or at least some steps in the conical tubing, must be engineered in order to make at least the 5th partials acceptable to equal tempered ears.

While the 5ths are out of whack in equal temperament, the thirds are so bad that the beats can hardly be discerned as such.

But then, that's why those of us not playing keyboard instruments have been given the gift of just intonation.

iiipopes · Post by **iiipopes** » Thu Apr 13, 2006 5:36 pm

Yes, and it sounds so much better and solid that way, when you don't have to play with keyboard instruments!

Sam Gnagey · Post by **Sam Gnagey** » Thu Apr 13, 2006 5:38 pm

There's a BBb helicon by that company in the museum at Blue Lake Fine Arts Camp in Michigan. While I was on the faculty there I took it out to play some Dixieland on in a recital. It is a truly awesome instrument. I would rate it at 5/4 size. The bore is at least .750". It has only one tuning slide: the main. It was a lot of fun to dance with playing the "Saints" and some other standards. There was one that came up on ebay a few years back. I wish I would have gotten it.

LoyalTubist · Post by **LoyalTubist** » Thu Apr 13, 2006 5:49 pm

Henry wrote:You want pure conical? Try a saxophone.

Put a cup mouthpiece on it and we are back to the ophicleide!

windshieldbug · Post by **windshieldbug** » Thu Apr 13, 2006 5:58 pm

Sam Gnagey wrote:It has only one tuning slide: the main.

And to keep the cyindrical bore to a minimum, all of Couturier's horns came with a set of three mains of different lengths, so that you'd never have to pull one out very far (or even could).