What's the deal?

[Donn]

I could be wrong, but I'm saying it's a big bell thing. Some seem to think York's to blame.

You don't mean bell flare?

What I think would be really interesting is the diameter at different places. A couple around the end of the bell, then maybe every 30 inches. Plot them and see what comes out, maybe referring to "Rick Denney"'s bi-radial vs. exponential idea and that sort of thing.

[Donn]

Sounds like some of us might be suffering from bell envy. Mine is bigger than yours, if it matters.

[tbonesullivan]

At least "recording" bells have fallen out of favor. Big, forward facing, and often hard to see around.

[BrassKicksArse]

An easy comparison is with a Miraphone 186 and a King 2341. Both types of tubas play great, but their sound is quite different. King is a small bore, big bell, while the Miraphone is larger bore with a smaller bell. Both offer completely different bell profiles as well. One offers a much more fluffy sound, while the other is much thicker.

[Worth]

I've always thought MOST horns with very large bells sounded "woofy", but poofy is a good descriptor, too.

Likewise smaller bells can sound "barky" if pushed too hard

Quote from Wyvern 2009 on another thread
"The larger bell certainly does change its tone to broader, more American. The old 15" bell I think was rather small as old Imperial's can too easily 'bark' if played hard, but going by my Melton 2040/5, a 17" bell might have been a good balance between character and broadness."

[2ba4t]

Yes, that bell width does make a big difference. The sound is, yes, ‘broader’ to our ears for good reason. The larger bore in last few yards also has an effect. And this not just because we imagine the difference.

The bell and the leadpipe control the physics as follows:

The vibration/push [sound wave] created by one single buzz [resonance] of your lips travels down the tube [air column]. [When you play the note A at 440 Hz your lips vibrate 440 times a second.] It then bounces back when it hits the ‘wall’ of the outside world air pressure AT THE BELL. The air pressure inside the tube is less than outside so the waves bounce back. [This is why instruments with open bells - are called ‘closed’ tubes!!!. [reflection in a ‘closed’ tube].] This all happens in a nano-second. That returning wave must fit perfectly with the very next split-second buzz coming down the tube from your lips.[positive interference] It finally reaches your lips in perfect time to be bounced back down the tube by your next buzz. That must match the next and the next etc. This pattern produces the best sound when the [standing] waves of pressure - travelling in opposite directions - meet in perfect synchronisation and ‘smash’ into each other [merge, high pressure points/ nodes] and then are immediately followed by the gaps - no pressure ‘spaces’ just behind each push [antinodes]. These must be perfectly aligned down the air column.

A vital point to note is that the LEADPIPE is central to all this because it handles the RETURNING WAVE and affects how it hits the lips So leadpipes really should be as narrow as possible to refine the return ‘flow’ and increase the reflection - but this would restrict the energy the player is putting in and feel too ‘tight’. Also, too wide a bell will dissipate so much energy that it will exhaust the player when he must put in raw energy [amplitude] to make a loud sound.

Millennia of experimentation produced Egyptian trumpets, Roman war tubas, natural trumpets, horns and sackbuts with profiles that did this best. Then valves were added. These chewed up the evenness of the air column [constructive interference of the standing wave(!!)] but not enough to outweigh their usefulness. So, you ended up with our modern tuba.

From all this, we see that the ‘bouncing back’ from the ‘wall’ at the bell is absolutely fundamental to each note. A bell will make the lower resonances respond better. This is why the fundamental harmonic is easier to play when the bell is larger. This is because the bell graduates the change to the outside air pressure and allows the sound waves to, conceptually, ‘slow down’ and bounce back with less interference. Perhaps imagine you are hurling hundreds of rubber balls down a pipe. The end is blocked. They bounce back and bang into each other as they do this. Now widen the end of that pipe like a tuba bell. Hurl them down again. They bounce back but interfere with one another far less inside that wider bell and jostle less violently as they eventually settle down in their path of journeying back up the narrowing tube.

So, yes, big bells make for easier fundamentals and a broader sound. However, they militate powerfully against a focussed clarity, immediacy of response, a ringing sound higher up and can produce an over-bearing, booming, un-brass-like sound when played as loud as possible. If this is above the bass clef, it destroys the effect of a brass section in, for example, Berlioz overtures etc. This also completely ruins all scoring for French tuba and old small bass tubas. Go replace a cello section with string basses. They are played brilliantly and with great beauty by our genius players today. But, except for Russians and 20th century composers, they are string bass players forced by fashion to play cello parts.

PS Like the rest of the instrument, the bell material - raw brass, lacquer, silver plating, satin finish etc is utterly, utterly irrelevant despite the mythology. The manufacturers have made millions out of this false news. It is a bare-faced lie.

From Subjective testing of Bells R. A. Smith, Unpublished Report, Boosey & Hawkes Ltd. (1977).

" Having taken precautions to equalise the weight and balance of the bells, ten of the best trombonists were put through a double blind test where the player is presented with a prescribed random order of instruments. (all players play the same order) {13} to ascertain whether they could distinguish between the six bells. The statistical results showed that the difference between thin and thick bells was so small that it could not be detected by any of the players. At a later stage in the testing an electroformed pure copper bell (made on a similar - but not the same mandrel) was added into the playing sequence. Under test conditions this was not noticeably any different to the brass bells but when subsequently played in non-blind tests it gained magical properties!
These results indicate that the bell thickness does have a significant affect on the sound spectra measured at the players' ear position due to some sound radiation from the material itself. However, under controlled conditions players seem unable to distinguish between thick and thin materials.

Proceedings of The Institute of Acoustics Vol.8 Part 1 (1986) - Traduction en français
The effect of material in brass instruments: a review.
Richard Smith
Richard Smith (Musical Instruments Ltd), 110 The Vale, London, N14 6AY

[windshieldbug]

All you need to do next is emote while you play.

People often mistake my horn for a flute, I move so much...

[Donn]

And more difficult to hear, for any fellow player who isn't located in front of you. Bass drum player complained after last show. "Lap sousaphones", indeed.

[roughrider]

At least "recording" bells have fallen out of favor. Big, forward facing, and often hard to see around.

LOL! Too bad, I say! A full and focused sound that works very well in the hands of a skilled player. YMMV!

[Heavy_Metal]

Thanks for sharing that, 2ba4t.

So who's gonna step up and admit "I like big bells and I cannot lie......"

[The Big Ben]

At least "recording" bells have fallen out of favor. Big, forward facing, and often hard to see around.

But nice in an outdoor concert band. Or any outdoor playing for that matter. And, you can put a cloth cover over the bell that says "Fritz Swinhundt and His Polka All-Stars". That's got to be worth something.

[Donn]

So who's gonna step up and admit "I like big bells and I cannot lie......"

I don't know about others, but for me, you'd have to be more specific. All tubas have big bells, and in my opinion it's a good thing they do. Please define.

[Donn]

He calls those results "significant", with the 2nd & 4th harmonic (partial?), but I'm unable to spot where he defines that term. If a bunch of good trombonists can't hear that 2 dB difference in those partials, then is it really significant? Meters can detect a lot of things that my senses don't. If it makes everyone happy that the differences due to bell thickness have 1) been discovered in the laboratory, 2) even if practically no one can hear them out in front, then I guess we're good.

[Matt G]

He calls those results "significant", with the 2nd & 4th harmonic (partial?), but I'm unable to spot where he defines that term. If a bunch of good trombonists can't hear that 2 dB difference in those partials, then is it really significant? Meters can detect a lot of things that my senses don't. If it makes everyone happy that the differences due to bell thickness have 1) been discovered in the laboratory, 2) even if practically no one can hear them out in front, then I guess we're good.

Yeah, even though the human ear works as a DFT (discrete Fourier transform), the psychological perception of the spectrum does things in analog space with approximations. That’s why we perceive the difference in overall timbre but unless trained on what a stronger second partial sounds like, we won’t know the difference. And 2dB differences of specific narrowband components are going to be really hard to perceive regardless. Especially with samples across non-calibrated sensors (people’s ears). To nail this study down, it could be done subjectively if you have a decent number of subjects, say 36 or so, have them all take a hearing test and determine their spectral response, and then have them listen to a bunch of different bells with several players and have them rank things and provide subjective feedback. You get some quantitative control that way.

[tbonesullivan]

At least "recording" bells have fallen out of favor. Big, forward facing, and often hard to see around.

But nice in an outdoor concert band. Or any outdoor playing for that matter. And, you can put a cloth cover over the bell that says "Fritz Swinhundt and His Polka All-Stars". That's got to be worth something.

True, but you can do that with a sousaphone too, and it's a bit easier to hold and see with.

of course part of me just wants everyone to go back to Helicons, which just look cool.

[Donn]

True, but you can do that with a sousaphone too, and it's a bit easier to hold and see with.

Maybe I'm doing something wrong, but in a sit-down situation, I sit a lot easier with my "lap sousaphone" than with my real sousaphone. The sousaphone doesn't get along with the chair.

[toobagrowl]

Especially with samples across non-calibrated sensors (people’s ears). To nail this study down, it could be done subjectively if you have a decent number of subjects, say 36 or so, have them all take a hearing test and determine their spectral response, and then have them listen to a bunch of different bells with several players and have them rank things and provide subjective feedback. You get some quantitative control that way.

Putting aside various levels of hearing loss for some ppl, I've often thought how everyone's ears have thier own "EQ", and that's at least part of why we all hear things a little differently, and have our own sonic preferences

[tbonesullivan]

Maybe I'm doing something wrong, but in a sit-down situation, I sit a lot easier with my "lap sousaphone" than with my real sousaphone. The sousaphone doesn't get along with the chair.

A good number of my tuba playing friends have drum thrones as their chairs, as they can more easily adjust the height, and it also allows them to get their tuba stand in a good position too. Doesn't get in the way of a Helicon or Sousaphone. Though, most sousaphones aren't really as "good" in many ways as most tubas, so I guess it's kind of a moot point.

[Donn]

My sousaphone is great, but I'll stand up before I'd bring my own chair!

The forward bell thread here is tangent to the "big bell" topic, I guess because forward bell flares are regularly larger than the alternative. As the very forward facing sousaphone bell flare is distinctly larger.

The way I understand this, the reason for this (perhaps contrary to intuition) to reduce the directionality of the sound - large bell flares broaden the sound projection, small flares focus it more. True? The same principles in operation on an upright bell.