Out-of-tune tubas

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Rick Denney
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Re: Out-of-tune tubas

Post by Rick Denney »

DP wrote:That may be true, but so fragging what?? Doesn't your face, your flexibility, your ear, your musicianship have anything to contribute?
Excuse the reductio ad absurdum, but if the length and shape of the tubing wasn't important, then we wouldn't need valves or slides.

So, at some level, the length and shape of the tubing is important. If so, there is a frequency of buzz that most easily achieves the fullest resonance, that is the most effective frequency for that length and shape of tubing. As the frequency of buzz departs from that optimum, some qualities diminish. There are those who can play a Bb while fingering a C, but they don't sound their best when they are doing it.

If we define the resulting sound of the instrument with a single quality factor (which is an oversimplification), then we could probably draw something that would look sort of like a bell curve. The X axis would be buzz frequency and the Y axis would be resulting quality. As some buzz frequency (our optimum), the curve would be at a peak, and it would fall away on either side of it.

We could postulate a second curve where instead of the resulting quality, we plot the ease with which an acceptable sound can be achieved at that buzz frequency. Again, there is a buzz frequency where it is easiest to get an acceptable result, and the further we are from it the harder it is.

Of course, the buzz frequency must be consistent with the pitches being played by the other musicians in the group. That's where our musicianship and ears come into play.

But what if that buzz frequency that matches the other musicians is not in the middle of that quality (or ease of play) bell curve? Then, we have to do something to improve the quality. I'm not sure that can always be done with the embouchure, because of where I started above--at some point, the embouchure cannot overcome the error in the instrument without losing something. We can adjust the length of the instrument as we play, which shifts the whole curve to where we want to do our buzzing.

I read Joe's remarks to mean that he wants a tuba where the center of the bell curve falls within the usual range of buzz frequencies needed to play with other musicians. I did not read it to mean that he wants a tuba that relieves him of the responsibility to hear and play correct pitches.

I think this was really my answer to the other thread that you started, but your post here is the first time I had an idea of what you were getting at.

To go on, some tubas have wide, flat quality and ease of play curves (and it may be that those curves are the same). Some tubas have narrow curves. Players who buzz accurately appreciate those tubas with wider and flatter response curves, because the sound on those tubas degrades less as they buzz away from the optimum frequency. Joe has described the CSO York that way, based on his one brief opportunity to play it. I think I would describe my Holton that way, too.

And we can perhaps widen and flatten that curve with a mouthpiece choice.

In practice, I use a several alternate fingerings on my Holton, often different depending on the group in which I'm playing. And I usually push the first slide in for the 5th-partial C. For example, I often play the 6th-partial F and the 8th-partial Gb and G using 7th-partial fingerings. That part of the scale of the Holton tends sharp for me.

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Re: Out-of-tune tubas

Post by Charlie Goodman »

MikeMason wrote:Scoob,your post subject is on my mind currently regarding my f tuba low register intonation.I'm getting better at playing the notes,but its a bit"fretless" down there.The pitches can be bent a half step pretty easily.I think this won't work for my quintet where I'm supposed to set the intonation much of the time.Great for matching others.Not so good for setting the pitch.I can play a note where it feels right and be 40c off.I can play watching a tuner or with a drone and line everything up pretty easy.Pick a low A out of thin air-could be waaayyy off.It's nice to be steered at least close to a slot.I'm starting to lose hope on using my f for quintet,but it's still great for solos and high orchestra.I guess it'll be the Thor for now.
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Re: Out-of-tune tubas

Post by MikeMason »

Well,my choice as I see it is, a great blending,appropriate size tuba with a nebulous low register,or a great sounding tuba with great intonation in all ranges but just too big.I guess the Thor wins for now.Quintet horn size is somewhat up for debate.Low A with a 40c wide slot is pretty much agreed upon as not good...I may take both and see how it goes.
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Re: Out-of-tune tubas

Post by Art Hovey »

Several folks above made remarks to the effect that the woodwind instruments are way ahead of us in terms of intonation, and I suspect that may be correct. Funny thing is, it's the woodwind players who seem to have the most intonation problems in the several different groups that I play with. Is it because they are unable to adjust their pitch, or is it because, like piano players, they never learn how?
Surely the good Lord distributed tin ears evenly through every section of the band, yet it's in the woodwind section where they are always most apparent!

Getting back to the original question: the "standing sound wave" in a brass instrument has "pressure antinodes" at several locations in the instrument, and that set of locations is different for each note. If the region near one of those antinodes is altered slightly by a dent or a manufacturing irregularity it makes very little difference. But if several of them are altered in similar fashion the combined effect becomes significant for that particular note even if the individual irregularities are nearly invisible.
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Re: Out-of-tune tubas

Post by iiipopes »

Art, I respectfully disagree about one point: if the antinode is in just the right place, a dent or misplaced brace can really alter the intonation and perceived "stuffiness" of a particular note. For example, on my Besson, there is an antinode on mid line D right in the middle of my valve block. Some time ago I had a dent taken out of the knuckle between the first and second valves that had occluded that particular port about 50%, and my mid line D went from perfectly in tune to 20 cents flat. I actually took the round end of a ball peen hammer, and gently tapped on that knuckle, ever so slightly putting a bit of the dent back into the knuckle until I got my intonation back. It did not, and has not, affected the intonation of any other note on the tuba.

Disclaimer: I discourage anyone else to try this at home. I was lucky to be able to experience a singular event in that I was able to see a direct effect on one particular note from one particular action at one specific place without having to consider multiple variables. Moreover, I have less than $750 invested in this tuba, including original purchase price, shipping, a couple of mandatory repairs, mouthpiece, and a few elective repairs. So if I had screwed it up, there is no significant loss. It would be just one more aspect of "personality," along with the holes in the rim from the tuba being improperly stored on its bell sometime along its 35 years before it got to me.
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Re: Out-of-tune tubas

Post by MaryAnn »

MikeMason wrote:Well,my choice as I see it is, a great blending,appropriate size tuba with a nebulous low register,or a great sounding tuba with great intonation in all ranges but just too big.I guess the Thor wins for now.Quintet horn size is somewhat up for debate.Low A with a 40c wide slot is pretty much agreed upon as not good...I may take both and see how it goes.
Methinks you'd be out some of your bank account just from trying a Norwegian Star. Perfect quintet horn, just dandy all-round. I'd get the Star Light if I felt like throwing the $$ around.

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Re: Out-of-tune tubas

Post by sloan »

Rick Denney wrote:

Good reading: The Physics of Musical Instruments by Fletcher and Rossing.

Rick "noting that this has been discussed in the past but without a clue as to how to search for it" Denney
Bingo on the reference. I'm out of town - can you please post the page number of the "figure that explains it all"? You know the one I mean... I love seeing the light bulb go off above people's heads when they first see that figure.

Better yet - can you please scan it and post a picture. Then we'd always have something to point at.
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Re: Out-of-tune tubas

Post by Rick Denney »

sloan wrote:
Rick Denney wrote:

Good reading: The Physics of Musical Instruments by Fletcher and Rossing.

Rick "noting that this has been discussed in the past but without a clue as to how to search for it" Denney
Bingo on the reference. I'm out of town - can you please post the page number of the "figure that explains it all"? You know the one I mean... I love seeing the light bulb go off above people's heads when they first see that figure.

Better yet - can you please scan it and post a picture. Then we'd always have something to point at.
Okay, here it is. From Page 217 of the book referenced above.

It shows that the pitches of the impedance peaks vary with respect to each other quite significantly with the ratio of straight to conical tubing in a compound horn. In English: The relative tuning of partials vary with each other a lot on the basis of the ratio of straight and conical tubing.

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Re: Out-of-tune tubas

Post by sloan »

And now...just for giggles...note that the "ratio of cylindrical to conical tubing" changes every time you mash a button...
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Re: Out-of-tune tubas

Post by Rick Denney »

bloke wrote:I've even heard of a manufacturer that made a bottom bow for a 6/4 BBb too narrow and too short...

Rather than starting over on the bow, they "V"-ed it out to line up with the bell and upper bow. Of course, the instrument played a bit sharp. Pitches that were normally flat on that particular model "seemed" in tune, but other pitches were horribly sharp...

:shock:
You're being a nasty bastard, heh, heh.

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Re: Out-of-tune tubas

Post by iiipopes »

At the last community band concert, warmup went well so we had a few extra minutes before actually starting the concert. I was able to lay my 1971 186 along side my colleague's newer 17 3/4 inch bell 186. The overall length of the horn is the same, but my bottom bow is tighter, and my overall wrap is tighter, necessitating the lengthened tuning slide to accomodate the retrofit upright bell that Dan Schultz did a superlative job for me.

His horn has a more "vanilla" tonality, and the usual trend of slightly flat 5th partials. Mine is right on for 2nd space C first valve, possibly slightly sharp for 12 B nat, alright for 2nd valve Db, and only needs the alternate fingering of 12 for midline D, and not always then, if we're somewhere in proximity to a 1st inversion Bb major chord.

But with the change in the overall balance between cylindrical and conical tubing, effectively delaying the start of the conical bugle, and then with the shorter St Pete bell being as wide or wider in the throat, so there is more expansion in less linear space, even if only a few inches, I can tell you that just like a flugel, my low range can go sharp if I'm not careful, and the top 1/2 octave of the bass clef can go flat if I'm not focused.

The tradeoff is more even overtones and a broader sound, which projects better, sounds "rounder" in all registers, and starts glimpsing east towards Alex territory.

I'm with bloke that the lower bow must have more to do with overall tone and intonation than most people would like to consider.
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Re: Out-of-tune tubas

Post by kingconn »

The thing is that all of the horn has alot to do with it. Although when you play the second partial the antinode falls somewhere 2/3 through the horn so generally problems in the lower partials tend to be in the last 2/3 of the horn. If you move your hand around when you play a long tone you can feel antinodes, any enlargment in the bore in these places will lower those pitches. You can lower the same pitch if you shrink the bore or the expansion of the bore at the node. The problem is when an adjustment is made and the node or antinode for another partial falls along the same area. Again ,only bore changes will affect intonation. Brace placement will only affect the response.
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Re: Out-of-tune tubas

Post by MaryAnn »

I just knew that picture was going to show up sometime in this thread!

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