What makes the sound?

[peterbas]

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[bloke]

non sequitur

Once the engineer understands the mechanics, they're stop.
If they never understand them, they'll never stop.

The air column and the air pressure (via air restriction - a venturi) cause the lips to (individually) vibrate.

Jamming the lips together and making a fart sound into an input receptacle does not cause the air column to vibrate.

[MiBrassFS]

My upper lip and lower lip are different. How to they coordinate to vibrate together and not produce their own frequencies?

Anyone cares to is welcome and invited to give their opinion.

[bloke]

My upper lip and lower lip are different. How to they coordinate to vibrate together and not produce their own frequencies?

Anyone cares to is welcome and invited to give their opinion.

It is because the frequency at which they vibrate is caused by the length of the column of air and the amount of air pressure sent past the lips.

How often - do you suppose - that the two blades of an oboe or bassoon reed are absolutely identical?

Those who believe that the two blades of a bassoon reed (as stiff as they are, and with a c. 1/8th-inch space at their arc, and only about 1/2-inch wide) actually bang against each other...well, I can only smh. Those who believe that the steel vibrating reed of a jaw harp wouldn't vibrate were it not that it's attached to a steel frame (even though that frame is dampened by being bitten down against by upper and lower teeth, and these being the very same people)...well, I can only smh at that belief as well. Those who believe that strings (whereby the apex of their vibration can easily be seen far away from either ends of the strings) that the only reason they make a sound is because the ends of them (which are nearly stationary when the central portions of strings are vibrating wildly) set the bridge and nut (or felt) of a stringed instrument into motion...again: I can only smh. (strings: I'm not referring to the obviously acoustic amplification which occurs - typically due to large wood structures to which the holding ends of strings are attached, and only referring to the fact that the string itself is vibrating - with the ends only acting as supports designed to interfere with that vibration as little as possible).

Though straying off to a completely different topic, these may (??) be some of the same people who believe that the mass of a brass instrument mouthpiece contributes significantly to the timbre produced (though the overwhelming majority never had two identical-interior mouthpieces - more-mass/less-mass - to A/B, and to even make a completely non-scientific judgement call, with many fooling themselves by what they expect to hear, and - further - the overwhelming majority of higher-mass versions of mouthpieces ALSO being interior-altered in some way - typically: larger throat opening).

ie. "Every time I pee outside, the mailman comes by the very next day."

[donn]

Those who believe that the two blades of a bassoon reed (as stiff as they are, and with a c. 1/8th-inch space at their arc, and only about 1/2-inch wide) actually bang against each other...well, I can only smh.

Meanwhile we're smh about 1) that "bang against each other" story that thoroughly misrepresents what happens, and 2) the denial of photographic evidence.

As far as I can tell, everyone else is talking about wind instruments. If you really think strings, jaw harp etc. are going to shed some light on this, you've taken on a fairly big job if you hope for anyone to see it. Ironically, it's the (invalid) string instrument analogy that leads people to the mouthpiece material/weight gimmicks, in hopes of "resonance" etc. Which is important for soundboards.

Photos/videos are from people actually playing.

Sure, and they show what happens when those people played, when the photos were taken. This is tautological. I don't think it proves that all players on every brass instrument always look the same - especially when the article says they don't. Without photos of a tuba player, moderate volume, middle range note like lower half of the bass clef ... I can't guarantee that lips would close in that case. They likely do, sure, but there's no inherent reason they must.

[bloke]

This picture is even crappier than that lips movie...

crappy pic.png (1.69 KiB) Viewed 679 times

...but
- The movie is low resolution.
- It's not known where the mouthpiece was drilled to insert the tiny camera. The ideal angle would be just below center (as most trumpet players play "down-stream", but that spot would interfere with the throat).
- The higher the pitch, the tinier the space between the lips (just as with the epic difference between oboe double reed and bassoon double reed openings). With trumpet playing, the arc becomes - again - just about microscopic, and the blurry movie is anything-but at the microscopic level, and nor (from what I've seen) is it pointed straight on at the nearly-microscopic space between the lips...so there's really nothing to be seen that demonstrates anything for certain.
- As you (finally) admit that you "can't guarantee that lips would close in that case" (as I contend that closing them would stop the vibration), why would they necessarily close at higher frequencies - such as a tuba player "squealing" out pitches way up at the top of the treble clef staff and above?
Why would a higher frequency range necessarily create an allowance or an exception?

summary:
- crappy low-res micro-camera movie
- unknown filming angle (which could well not reveal the opening, due to where the hole is trilled and how the mouthpiece is "clocked")
- admission that lips could possibly vibrate without touching each other
- as lips (and oboe reed blades vs. bassoon reed blades) become infinitely closer to each other (as the frequency increases) they can certainly become closer-and-closer to each other, YET never actually touch (at the tinier-and-tinier spot where they continue to vibrate at higher and higher frequencies).

One of you just loves charts and graphs. Here's a graph showing an arc whereby the arc creeps infinitely closer to nothing, YET never reaches nothing:
(something I was shown in elementary school)





Seriously, you two guys are pm-ing each other and coordinating your trolls, yes?

Also:
I've heard that people who deal in "engineering" and "science" stuff - who encounter others who disagree with their observations - often embrace a hobby of (regardless of what actually is - which isn't the point) attempting to demonstrate that those - who disagree with their findings - are foolish or stupid...(again: a whole bunch like the totalitarian/equal distribution/keynesian -vs- libertarian/free-market/hayekian arguments on social media). I'll READILY ADMIT that I am both foolish AND stupid, if that's what y'all are attempting to pull off.

[donn]

- As you (finally) admit that you "can't guarantee that lips would close in that case" (as I contend that closing them would stop the vibration), why would they necessarily close at higher frequencies - such as a tuba player "squealing" out pitches way up at the top of the treble clef staff and above?

It's tedious to be interrogated by someone who doesn't seem to have read what I wrote. I have been at some pains to repeatedly point out that, as i understand it, whether the lips touch does not matter to the production of sound. I have several times on preceding pages of this thread presented quotes wherein the physics story is that the lips apparently do not touch in some playing situations. When is that? They say, with high notes, and they say why. You can go back and read it if that's interesting to you.

As you have defined the corner you back yourself into, it's entirely appropriate that you can define your way out of it by means of infinitesimal approximation. Where the rest of us see the bassoon reeds in contact, your faith allows you to know that even so there's that molecule layer of air in there. OK, suit yourself. The point is, it doesn't matter. The resonating air column will bring the closed reed back to fully open position, just the same way as it would if there were really that tiny space. When the player has a working balance of air flow vs. the air column, the tone generator vibrates with the air. Closing is neither essential, nor disruptive, it's just an effect of the particular tone generator.

[Stryk]

[peterbas]

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[peterbas]

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[peterbas]

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[donn]

My upper lip and lower lip are different. How to they coordinate to vibrate together and not produce their own frequencies?

Anyone cares to is welcome and invited to give their opinion.

The standing wave makes the air pressure in the mouthpiece positive and negative.
Both lips follow the change in pressure, what doesn't mean that one can be longer then the other.

Yes, it isn't like your lips produce frequencies the way a guitar string does, out of their own resonant properties. The air column is the resonating element, here. Lips play a role, but not that role, so it luckily doesn't matter that a lip really doesn't have any resonant property at all.

Here we could go back to where we started on this wacky journey years ago: what about when you buzz into the air, no tuba and no resonating air column for your lips to work with? But of course we're not going there. Who cares about that?

[donn]

It isn't that because of some exceptions which will probably exist that you can dismiss the positive and negative pressure in the mouthpiece forcing the lips in and out and the fact that the efficiency of the standing wave being reflected is the highest when it hits a solid object and not one with a hole in it, that you can state no inherent reason with a high probability factor.

If I understand you ... I'm just going from the resource you posted, where 1) they believe that under some playing regimes the mouth doesn't actually close, and 2) they explicitly say

For a sound wave, the tiny aperture between the lips – which is on average a much smaller cross section than the bore of the instrument – is enough to cause a reflection approximately like that from a completely closed end.

I.e., a hole is enough like a solid object, if the hole is relatively small. If you think that's too sloppy, maybe you'd like to present a discussion of the acoustical closed pipe in terms of a regime where the solid object appears at only one point in the cycle, and during other parts of the cycle there's a hole. I don't know enough about it myself, to say whether that's sound - if the reflection effect happens to apply only at that bottom pressure.

[edit] You may obtain extra credit for a discussion of the same principle in the saxophone or clarinet, where I believe we agree that the reed doesn't always close. [/edit]

[peterbas]

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[peterbas]

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[peterbas]

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[MiBrassFS]

I have a “double buzz.” I am generating two waves, but they are different and out of phase. Sometimes slightly out of phase, sometimes completely out of phase. This results in varying degrees of severity.

Any and all are invited to address and explain this phenomenon from your point of view.

[russiantuba]

I don’t think about my lips when I play or think about embouchure nor do I teach it. Then again, I’m rooted in Jacobs/Rocco pedagogy.

If everyone participating in this thread put the same amount of time spent in they spent on this thread into developing their sound, a few more people than the “Tuba God” might have a world class sound

[bloke]

@MiBrassFS

You need to take some lessons, so you can tune up your double buzz.

Hey...
Did you notice that I trolled some more charts and graphs?

[MiBrassFS]

Hey...
Did you notice that I trolled some more charts and graphs?

Hey…
Did you notice that my couple of shots of anti-troll spray ground this thread to a halt?