Bell size and sound

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DouglasJB
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Bell size and sound

Post by DouglasJB »

For those who have worked on custom horn, have built horns or have messed with altering parts, how does the size of the bell on a horn alter the sound?
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bort
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Re: Bell size and sound

Post by bort »

The effects of a bigger bell will be greater if you also use a bigger bottom bow.
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Roger Lewis
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Re: Bell size and sound

Post by Roger Lewis »

I worked with Jens Bjorn Larson on the development of the Thor which had a 17 3/4 inch bell in the original release. It tended to play rather aggressively. A year later at the factory I asked them to put a 19” bell on one for me to try. They did and the difference was that the larger bell took the aggressive tendency out of the sound. You could still make it play the way it did in the first design but the larger bell melllowed it out a bit and added more projection. That is why Miraphone went with a larger bell on the 1293. It was to balance out the sound through all registers.

Just my $0.02.

Roger
"The music business is a cruel and shallow trench, a long plastic hallway where thieves and pimps run free and good men die like dogs. There's also a negative side." Hunter S Thompson
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Donn
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Re: Bell size and sound

Post by Donn »

DouglasJB wrote:the size of the bell on a horn
Do you mean the bell flare, or the entire bell, the whole large conical last piece on the tuba?
Lee Stofer
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Re: Bell size and sound

Post by Lee Stofer »

Douglas,
In one question you are asking about a number of variables.

The bell flare makes a difference, in that a smaller bell diameter on a given throat will make for quicker response but less radiation of sound, whereas a larger bell flare tallkes a little longer to respond, but is also a larger radiator of sound. This is also affected by a number of aspects of construction, such as metal thickness, metal hardness, the alloy used, and whether the bell rim has a steel wire inside, a bronze wire, or is hollow, and whether or not it is fitted with a nickel-silver outer rim.

The bell throat makes a lot of difference. J.W. York used the same bell flare for it's monster Eb tubas, and all of the contrabass tubas. If you set a York monster Eb tuba, a model 33 4/4 BBb, a model 712 5/4 BBb, a model 91 6/4 BBb and a CSO York CC tuba side-by side, the only difference you'll notice in the bell flares are that the throats of each model are different, and that the rim of the 6/4 BBb was spun out to 22". Otherwise, the flares are all the same. On the monster Eb and 4/4 BBb, the effect is a large bell flare on a very conical, short bell throat that allows one to get a tremendous amount of sound from a relatively compact instrument. The 5/4 York bell has the same bottom bow as the 4/4 York, so the longer bell throat is less conical and the bell flare is proportionately slightly smaller, and having owned one and worked on several of these, as much as I love playing one, they do not respond as easily as the model 33. They sound great and will rattle the chandeliers, but they take more effort to play. The 6/4 York BBb's have an enormous body, bottom bow and bell throat, so a 22" bell flare actually works quite well on these giant tubas. The CSO Yorks are two one-off, custom made instruments that are in fact smaller than the 6/4 BBb's. The most highly-considered of these (#1) has a shorter bell throat, so the bottom bow was most likely made a little larger on the large side to accomodate the bell throat starting at a slightly larger size than that of the other CSO York or the BBb Yorks. And, not widely known amongst players is the fact that bore affects pitch, so the larger the bore of an instrument generally, the shorter it must be made to be in tune. The result with the CSO York #1 is that it is an extremely conical, short, large-bore CC tuba with a bell flare no larger than that of a 4/4 York model 33, which allows this very short, fat CC tuba to have a real immediacy of response, while a 20" bell rim allows for plenty of radiation of sound. In an A-B test at Symphony Hall in Chicago of a Rudolf Meinl 5/4 CC (6/4 tuba) and CSO York #1, it was noted that the York responded slightly quicker, but the sound of the Rudolf Meinl had a slightly longer resonance afterward. The Rudolf Meinl has a slightly larger and longer bell throat, and the same bell rim size as the York at 50cm/20".

One could study for years all of the variables and how they interact.

If you're thinking of tinkering with the bell on your Kanstul model 80 F-tuba, my advice is - DON'T. That is one of the best-responding, most gorgeous-sounding F-tubas ever made, and messing with the bell will not improve it. My $0.02.
Lee A. Stofer, Jr.
DouglasJB
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Re: Bell size and sound

Post by DouglasJB »

No, I'm not messing with my Kanstul, no worries about that, it is an awesome little horn.

Maybe to make it a bit easier to answer for everyone... looking at Eb tubas, with similar bell throats, what are the pros and cons of having a 17 or 19 inch bell? Im just trying to understand why one is preferred over the other and fornwhat reason. I realize I left the question vague.
Heavy_Metal
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Re: Bell size and sound

Post by Heavy_Metal »

A related discussion. See the linked Rick Denney article:

viewtopic.php?f=2&t=87986&start=20" target="_blank
Principal tuba, Bel Air Community Band
Old (early 1900s?) Alexander BBb proto-163
1976 Sonora (B&S 101) 4-rotor BBb
1964 Conn 20J/21J BBb (one body, both bells)
1970s Marzan Slant-rotor BBb
~1904 York 3P BBb Helicon
Old Alex Comp.F, in shop
euphomate
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Re: Bell size and sound

Post by euphomate »

bloke wrote:
DouglasJB wrote:No, I'm not messing with my Kanstul, no worries about that, it is an awesome little horn.

Maybe to make it a bit easier to answer for everyone... looking at Eb tubas, with similar bell throats, what are the pros and cons of having a 17 or 19 inch bell? Im just trying to understand why one is preferred over the other and fornwhat reason. I realize I left the question vague.
Typically, the contours of the 15", 17", and 19" bells (found on 3+1 Eb tubas) sport identical contours (particularly if all the same make). The pancake just grows from one size to the next.
I DO NOT NEED but would LOVE TO HAVE a really great condition modern-pitch 3+1 Edgware Street 15" bell Eb tuba.
Does this mean a 15" bell Boosey & Hawkes Imperial compensating Eb? I use one, they were made from leftover British army tanks after WW2, and were dropped by the Royal Air Force as bomb ordinance when they ran out of ammo. Made to last for ever, but take a lot of work to speak, compared to the later Besson Sovereigns.
Besson BE982 Sovereign EEb tuba
Wessex Champion EEb tuba
Stencil compensating euphonium
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