TubaForum.net

bloke wrote: ↑Tue Jul 13, 2021 12:14 pm bloke "Please do not ask me to record myself 'saying' the Pledge of Allegiance on the trombone. "

Uncle Buck wrote: ↑Wed Jul 14, 2021 12:30 pm

bloke wrote: ↑Tue Jul 13, 2021 12:14 pm bloke "Please do not ask me to record myself 'saying' the Pledge of Allegiance on the trombone. "

Please record yourself 'saying' the Pledge of Allegiance on the trombone. Pretty please.

bloke wrote: ↑Wed Jul 14, 2021 12:32 pm If you will make a recording of yourself play-saying along with it, once I upload it.

bloke wrote: ↑Mon Jul 12, 2021 8:14 am Rather, it’s a means. Again, we really don’t have a way to vibrate our lips without blowing air between them, but – if we did – I submit that the air column would still vibrate sympathetically with the vibration of the lips.

Three Valves wrote: ↑Fri Jul 16, 2021 7:14 am Vibration with no flow??

Say it ain't so!!

Three Valves wrote: ↑Fri Jul 16, 2021 7:14 am Vibration with no flow??

Say it ain't so!!

bloke wrote: ↑Wed Jul 14, 2021 2:53 pm For personal religio-philosophical reasons, I just don’t embrace/recite pledges to things that are controlled by men (particularly when goals/objectives can change drastically every 2 to 4 years). I wouldn’t mind doing this for one person - who might find it amusing, but there are quite a few people who would probably be offended, so I’m not going to make a video/post a link.

peterbas wrote: ↑Sat Jul 17, 2021 3:46 am

iiipopes wrote: ↑Fri Jul 16, 2021 8:33 am

Three Valves wrote: ↑Fri Jul 16, 2021 7:14 am Vibration with no flow??

Say it ain't so!!

It's called static wave theory. The best example is waves on a body of water with an unattached buoy with no or very little wind to drive the buoy. As the waves flow across the body of water, it is due to static wave theory, not flow theory. The buoy bobs up and down with the waves, but does not travel with them, except possibly slightly due to the wind which causes the waves. Same thing in a music instrument. The other classic example is the ball park spectator crowd: as "the wave" goes around the ball park, it looks like it is moving, but each person only raises his/her arms then puts them down, but doesn't move from the assigned seat. Once the energy transitions the throat of the mouthpiece, it sets up the pattern of compressions and rarefactions that constitute the vibrations we call pitch, but without flow. There is a famous experiment that smoke is blown into the lead pipe of a tuba. Then the tuba is played normally, observing when the smoke might be seen to be coming out the bell. Because there is minimal, if any, actual flow of the air after the transition, it takes a long, long time for there to be any wisps of smoke to come out the bell. Light photons work in a similar way, as photons are (oversimplified) both matter and energy, but I'm not going to digress into the physics equations. Yes, in some circumstances, there is vibration with no flow. A tutorial:
https://www.physicsclassroom.com/class/sound/u11l1c.cfm

To many misconceptions to let this slide by.
First, it is called a standing wave and it is no theory because these wave exist in real life. The theory is how we explain the wave occurs, but the wave doesn't care about that.
The example of the bobbing buoy is not very good because the move mostly because of transversal waves in the water. Standing waves or hard to detect in open water. Take a surfer, with a transversal wave he moves up/down and also forward. With a standing wave he would just go up/down but he would never reach the beach.
There are standing waves in open water like in the North Sea where there is a standing wave with a period off 36 hours. Now that is what we call a pedal note.

Second, standing sound waves are longitudinal waves. So are surfer would now move back and forth but also never reach the beach.
A perfect standing wave in a tube needs an energy source and two perfect reflection points and it would go on forever. But we need all kind of stuff like a mouthpiece as a player to get energy inside the tuba. Then when a standing wave is formed we should mimic a perfect reflection point as to loose as minimal as possible energy to get a high efficiency.
On the other side we surely don´t want a perfect reflection point because the there would be no sound. So the bell/atmosphere transition is made so bad in energy transfer that most of the wave is reflected to keep it going and a small part is projected into the surroundings so people can be in awe with us, the fantastic tuba players.

The most famous instrument without an air generator must be a tuning fork. Just give it a whack and instant sound occurs.
Another one is a singing glass, there the movement of your fingers is the generator.
https://www.youtube.com/watch?v=gDm4IphrlYg

I think the confusion is because sound waves need a medium to travel through and most of the time that is air. So it can be difficult to make a distinction between air as a generator and air as a medium.