A series of questions regarding building an instrument

[tubamirum]

Regarding the ringing, get enough aquarium tubing to go around the rim if your bell, slit it and put it on, should do the trick. Pitch for bending is not expensive, I heat mine in a coffee can and bend the tubes around wood forms, be sure you anneal the tubing first. Good luck

[Dan Schultz]

As tubamiran said... a split length of vinyl tubing around the bell should fix the ringing.

As far as adding nine feet of tubing to a BBb sousa goes... you will probably end up with something that is TOTALLY unplayable. Sousaphones aren't widely respected for their intonation anyway... and that much additional tubing would probably REALLY screw things up. About the only choice you would have with a sousaphone configuration would be to add straight bore tubing. You will also have to add the same percentage of lengths to the tuning circuits.

Of course... if you have plenty of time and money... there's absolutely nothing wrong with doing a little experimenting. Let us know how it goes.

Bending DEAD-SOFT (that's important) tubing is no big deal when working with straight-bore stuff. Pitch is messy but will get the job done. I keep a crock-pot full of it and when I see I'm going to need it... I just plug the pot in a couple of hours ahead of time.

[iiipopes]

I absolutely agree. Even adding only 4 inches of cylindrical tubing to make my replacement bell playable changes the intonation characteristics of my horn. Oh, but as for souzys and their intonation -- the 38K I play does very, very well indeed, thank you.

All souzys with a Conn-style block should have the upper loop of the 1st valve circuit made into a left hand tuning slide just like a concert tuba. Then like any 3-valve horn, set 3 long so 2+3 is in tune or slightly flat, and if it is a good quality build it should behave as any other good tuba.

[Tom]

Maybe I'm the only one, but I don't understand what your objective is.

Your first post indicates (to me) that the instrument actually plays pretty well since you described only a "few minor note issues, primarily dealing with the F# ringing after I stop playing."

So you want to add straight bore tubing? To the "open bugle?"
What do you want the pitch to be?
What sort of result are you looking for after you add the tubing?

If you want to spend the big bucks to have a pro build your fantasy tuba/sousaphone/helicon/whatever, then I ask "why?" If you intend to have this be a DIY project, then I'll say that you'll invest a lot of time and money (supplies, tools) into something that might ruin an other wise pretty nice playing instrument.

Remember that no instrument is perfect. If the worst problem you have is an F# that rings, count yourself lucky.

By the way, I would look in an entirely different direction for the source of the ringing as I don't think it has a single thing to do with your valve set, bore, etc.

While some instruments do resonate or ring on a particular pitch, older instruments in particular often buzz or ring because of a beat up bell wreath (probably don't have one on this instrument though), broken bell rim wire, loose/broken solder joints, ill-fitting/out of round receivers (so mouthpiece won't "seat"), etc.

Sometimes objects in the room will buzz or ring too...have you experienced this in multiple locations?

[imperialbari]

You likely would be more successful with a new design for your kilt:

[TUBAD83]

"Don't f--- with success!"

Lucille Ball

[Rick Denney]

If you ever get a chance, you should play an actual subcontrabass tuba before you proceed with your plan. I think you'll find that adding 18 feet of tubing will utterly undermine the resonance of the instrument to the point where you'll have a hard time making any decent pitch at all. And don't think that blowing a 28-Hz Bb is any easier on the second partial of a subcontrabass than it is on the pedal of a contrabass. It will still take the air required to sustain a 28-hz buzz, with reinforcing pulses taking twice as long to come back from the bell (if they make it back). I think you'll find that it will take five of you on subcontrabasses to match the dynamic of one player an octave up.

And even if you achieved a hearable volume, most people can't hear pitch down there anyway, and it will just sound like someone making fart sounds in a brass trash can.

But, as they say, it's your horn.

Rick "who has actually attempted to play a subcontrabass" Denney

[DavidK]

Ringing notes.

If the ringing note can be reproduced at different playing venues or out doors, then it is the horn and a natural resonance. If it is only in your practice room, then the room is a contributing factor.

I have a few of these in my house and found that when I practice in one location that the hardware on the front door (door deadbolt and door knocker) vibrate on concert A's and D's.

If it is your horn, then have a friend pinch your bell rim while you play the offending F#'s. Try holding/pinching the bell rim, working their way around the circumference pinching different locations on the rim. See if any specific locations cause the resonance to stop. You can try this experiment alone with clothes pins or small spring clamps. Mark the spot(s) and then ask Dan Schultz what he would do. Check the soulder, crimp the rim slightly with a vice grip, hit it with a bigger hammer ?!?!

Happy hunting!

[Dan Schultz]

..... Lastly, how do I measure the length of the open bugle - is it all the way to the edge of the bell or just to the opening of it from the gooseneck or bits? And for that matter how to measure slide lengths.....

The 'open bugle' can be measured from the end of the bell to the end of the mouthpiece. It's not an exact measurement and is affected by most everything else including the diameter of the bore, the taper of the bore, and the bell diameter. Actually... 18 feet for a BBb tuba is a half-wave length of the fundamental pitch. The sound waves are reflected and the REAL length is somewhere beyond the end of the bell. I would almost guarantee that a tuba that measures 18 feet from the end of the bell to the end of the mouthpiece will be FLAT.

Here are some dimensions that you can 'fiddle' with but bear in mind that with the acoustical properties of musical instruments... nothing is exact and each 'frankenhorn' has to be approached as a prototype.

BBb Tuba 18 ft. open pipe
CC Tuba 16 ft. open pipe
F Tuba 12 ft. open pipe
Eb Tuba 13.5 ft. open pipe
Bb Euph/Tenor Trombone - 9 ft. open pipe
Bb trumpet/cornet - 4.5 ft. open pipe

Tuba tuning circuit lengths:
Valve tubing lengths:
F
1st valve = 18"
2nd valve = 8"
3rd valve = 27"
4th valve = 48"

Eb
1st valve = 20"
2nd valve = 9 1/2"
3rd valve = 29 1/2"
4th valve = 52"

CC
1st valve = 23.7"
2nd valve = 11.257"
3rd valve = 34.957"
4th valve = 61.62"

BBb
1st valve = 26.66"
2nd valve = 12.66"
3rd valve = 39.32"
4th valve = 69.32"

BTW... the two and three place decimals are only interpolations from the original approximate data. The information here is not intended to be exact.... only a reasonable starting point.

Go with the garden hose trick and trim the length until you get the result you want.

[Dan Schultz]

Dan, if I understand those approximate lengths correctly, I would need to double the length of the Eb and then subtract the BBb length to get these:
1st : 13.34"
2nd : 6.34"
3rd : 19.68"
(4th) : 34.68"

Which would make an approximate EEb subcontrabass sousaphone.

......

I guess I'm a little confused as to what you are trying to accomplish. Using those dimensions for the tuning circuits is going to give you something that is pitched higher that the tuning circuits of a BBb tuba. Is that what you are trying to do?

[MartyNeilan]

Bell ringing:

The easiest way to address this is to get some clear plastic tubing of the appropriate diameter (icemaker line is often good), slit it lengthwise, and wrap it around the bell rim tightly. You can either overlap a couple inches to hold it, crazy glue it, or use a low temp soldering iron to melt it together.

[imperialbari]

Maybe eight years back on old TubeNet There was a couple of threads based on bloke reporting, that the un-denting and un.creasing of the bell of a certain sousaphone, maybe a Reynolds Eb, had introduces a ringing/afterglow that had not been there before.

I remember my own postings based on my then 3 front bells: 26K. 40K, and Your Master BBb (22" bell). My points were:

Creases stiffen the bell like creases are used at will in car designs to create stability. Corrugated iron for barn roofs and corrugated sides of old style iron buckets are other samples.

The larger the bell throat is compared to the bell diameter, the less likely ringing/afterglow will be.

Based on my more recently acquired 28K I got one more experience on this matter. Due to experiments with a K&M stand and with attempts of making a homemade stand I changed the bell rotation a few times. Suddenly there was a ringing/afterglow not heard before. As far as I could deduct, the reason came from the way the collars were joined. Most often they are joined slightly off-axis, so that the bell doesn’t sink down in the formally ideal position. This introduces q tension on the bell, which keeps the ringing/afterglow away. When I by hazard got the bell correctly seated, there came a very pronounced ringing when playing notes derived from fundamental C or its overtones.

Klaus

[Wyvern]

I would think if you just lengthen to EEb, or BBBb then what you will just get is a VERY stuff Sousaphone. To increase the depth of tone, what you need is a larger bell throat. You would be much better to search out a Conn Jumbo 48K to produce the kind of sound you desire.

Good luck!

[imperialbari]

If part of the outer flare area has been dented, creased, or overly flattened, that area actually will be the one least likely to cause the ringing/afterglow.

If the bell is perfect and also is perfectly seated in the body, there is less tension, and the outer flare area is more likely to wander off on its own road causing the ringing/afterglow.

King is said to have done research telling that huge bell flare diminish the sensed playing resistance. But most often the really sought after orchestral tubas don’t exceed a bell diameter of 20".

Klaus

[Wyvern]

I'll be heading down to Okemos tomorrow to have a look at the "Majestic Monster" and I'll post some findings and pictures (!) when I get back.

That will be very interesting - look forward to seeing!

[randy westmoreland]

You are still practicing that gorgeous Holton 345 right. Just hit that Bordogni!

[Oceantuba]

Likely it's all been said but just to be sure....

In general, with brass instrument design, you need to "respect the bore". (Pretty sure this is a loose translation from French) My thinking is that this applies to almost every aspect from mouthpiece to bell.

Conical tubing has to be the right dimensions acoustically.

By the time you add the extra tubing, you would likely exceed the bore of the original instrument.

Bending tubes isn't too hard. I learned a bit about that. We used lead. (oil in bore first) But bending the branches for a Sousaphone requires some big jigs, hooks, lots of lead/pitch etc. Something I was only told about, albeit from an experienced person.

You would need hooks to work the metal when bending conical tubes. Likely the same for straight tubes.

[sloan]

BUT, a couple days ago I had an epiphany; why not just add a bunch of tubing to drop the pitch?

Please - do this with temporary tubing (the right size hose should be OK) and report back on the results.

I'm particularly interested in exactly how badly this will screw up the horn's scale.