Organ Pipes theory & practice #1 - effect of the beard and ears
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- čas přidán 11. 12. 2022
- Disclaimer, not being a professional organ builder, what I say in this video is based on my studies on the subject and on my personal experience as an amateur.
In this series of videos, I'll cover the theory behind organ pipes, with hands-on demonstrations.
Organ Pipes theory & practice #1 - effect of the beard and ears
My channel topics are: Homemade pipe organ, portative organ, positive organ, organ buildings
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Doing the smoke test I found that half of the pipes of the portable organ were leaking at the cap, nice😄
That must be satisfying.
Yes please continue with this content.
I like your construction and performance videos - obviously - but from time to time a small informative video like this one is the cherry on the cake!
Maybe contact the slomo-guys (youtube channel with high speed slow motion) can really show the airflow and impact of it to the tone.
Anyways: BRAVO
Thanks Sir, yes my slow motion is a bit weak..😅
This is fascinating to see in it’s fabricated form, I’ve been wondering about the result of any certain variables being adjusted and how that may alter timbral character. The organ building volumes by George Ashdown Audsley have been so very helpful, but seeing your demonstration has shed a new light for me. Thank you!! 😊
I agree, Thanks for your comment!
Thanks for the video!
Thanks!
Very good.
Thank You Anna!
Molto molto interessante e fatto benissimo come al solito! Spero farai altri video di questo genere e sull’intonazione e dove agire per modificare i parametri del suono! Complimenti vivissimi!
Ciao, grazie. Si ho in programma una serie di video "didattici"
We need attempt to make reed pipes now!!!
I'll do it soon!
@@nippocast wow! Super cool! And if one day you achieve to make metal tin-lead pipes I call you mister! Same for huge 16 foot 32 foot pipes 😊 I start myself making some pipes. Greats fron Switzerland 🇨🇭
Very much enjoyed this video. Your caps are leaking, but beyond that it's difficult to see the difference between the air flow of the two pipes. When comparing the tonal quality it's best to use pipes of the same pitch so tonal quality is the only difference. Someone told me the beard was the round piece often found on bass bipes, and the ears are there to hold the beard and to guide the air flow. The beard was to keep the air flow from being too scattered.
Thanks steven, yeah, you're right. In this pipe the in this pipe the beard is considered the not beveled profile of the cap coinciding with the internal block
👏👏👏
Sei tu? Ciao Mariano!
@@nippocast sono io! Ciao❤️
Thanks!
This is great information. I know there is much published information on pipes, but I don't generally have time to seek it out. What publication did you source your presentation material. Great illustration using smoke.
Grazie mille Ralph!
@@ralphmilroy6460 predominantly from "the art of organ building Vol.2" 1300 pages packed with information, a book by George Ashdown Audsley
@@nippocast "The art of organ building Vol 2" . . I have that book. George Ashdown Audsley was an architect and organ pipe builder. His is considered to be the best book ever written about organ pipes.
Tanks for your sharing tutorial,,
How much difernt, pipe from wood and steel, for the tune,? And how much register can build from wood pipe?
Apart from the difference in construction and sonority, both in terms of tuning and the amount of buildable registers they are similar
Thank you from Brazil. Might I ask you something? I would like to know how to do a Vox Humana pipe. I KNOW THAT IS REED PIPE, but VH has a long shallot and a resonator opened. MIGHT you do a video doing this stop or explaining, very please?
Thanks! yes, I don't know when yet though.
@@nippocast okay, within your time, dont worry! Thank you! Maybe someday Im thinking do videos about harpscihord and organ making.
The thing with this is that it doesn't ACTUALLY explain why the organ pipes have the sound they do.
As far as we know, the air flowing into the pipe forms a jet, and depending on the position of the jet it either goes into the pipe or flows out of the mouth, and it's this oscillation in jet position that forms the sound.
The catch is that this oscillation is, as far as we can tell, essentially a pure single frequency sine wave. If the air flow into the pipe depended only on this position in a direct linear way, every organ pipe would have the same pure mellow timbre. To get any other variation in timbre, you need something non-linear or non-direct in this relationship, and there are over a dozen plausible ways in which this can happen, and this type of test tells us nothing about which ones of the plausible ways to create overtones is the one that's actually true.
Plausible explanations for overtones:
- The jet-position to airflow relationship might have a curve rather than be linear. This is certainly at least partially true, as at some point all the air is going into the pipe or all the air is going out of the mouth. This relationship explains pipes that produce odd harmonics very easily. The problem is that it's hard to explain pipes with significant even harmonics with it (such as string pipes), as curves that produce even harmonics are asymmetric and normally even divergent, which would create an energy blow up. You need to factor in at least one other variable into the curve that produces airflow (making the curve 2D or 3D or N-dimension). The paper "The Physics of Organ Pipes" by Fletcher in 1983 uses this explanation.
- The momentum in the change of jet position might factor into the airflow too. This could explain pipes that produce soft even harmonics (diapason etc), although it might be harder to explain pipes with sharper timbres as it would require a relationship with a sharper discontinuity.
- The jet position might change the reflectivity of soundwaves bouncing off the near end of the pipe. This could make for soft even harmonics, although reflectivity in the pipe needs to be high for this to create sharp waveforms.
- The returning soundwaves might interact in a non-linear way with the relationship between jet-position and airflow. This could explain even harmonics, but it might result in chaotic interactions though.
- Some other airflow characteristic might oscillate and influence the airflow waveform. This extra airflow characteristic could have any waveform - sine wave but phase shifted relative to jet position, some kind of pulse or impulse or saw-like oscillation, a higher overtone, partially chaotic oscillation etc. The number of plausible alternatives is high and it's hard to weed out which ones can apply, and they tend to lead to chaotic behavior.
- Some of the airflow might be accumulated during some part of the jet position oscillation and released as the jet position crosses a threshold. This explanation could explain sharp even harmonics but tends to be affected by thresholds. Perhaps a better candidate for reed pipes (controlled by reed position rather than jet position) than flue pipes.
- Some of the harmonics in the return wave might bleed into the jet position, resulting in a cascade of higher harmonics. This is probably true to some degree... It doesn't explain how even harmonics might start, but if there are some even harmonics in the sound, this can create more sharper even harmonics.
- The speed of sound varies by air density, which can create an effect where a decrease of air pressure compounds itself and creates a sharp pressure change. Brass instruments have high pressures that do create this effect, though it is perhaps not very prevalent in organ pipes.
- The overtones might be created by sharp variations in the flow out of the mouth, rather than variations of flow into the pipe. The difference between this kind of effect (vs effects on flow into the pipe) is that it cannot create cascading timbre variations (it's strictly a function of jet position and whatever other effects influence airflow), and so it responds instantly to air pressure changes rather than with some latency.
- Air jet position might not evolve in a strictly sine-wave manner. This is certainly true to at least a tiny degree, as it's hard to produce fast startup of oscillation without a little bit of nonlinearity in the jet motion. This type of process tends to create pitch variations - for instance pipes going sharp or flat as pressure is changed. Objects near the mouth or the air intake hole might create a secondary airflow, and drag on this secondary airflow might change pitch a lot. This also tends to create chaotic oscillation, so it might not explain the pipes with more overtones very well.
- The amount of air flowing through a small gap can saturate or otherwise behave nonlinearly through things like the Bernoulli effect and vortexes and air velocity effects. This is the realm of fluid dynamics and things like the Navier-Stokes equation. This is the kind of effect that explains the noise component of organ pipe tones, but they are hard to reason about and it's difficult to figure out which ones apply at the right scale and in the right way to explain organ tones.
- The balance of harmonics emitted might be quite different from the balance of harmonics in the intake airflow, due to effects such as high harmonics being more easily radiated. This doesn't explain the creation of high overtones, but it might explain their prevalence in the final timbre heard.
We don't really know which ones of these apply and to which degree. There is still so much we don't know!
.
Thanks!
Why do you think that smothering your naration in annoying "music" improves it or makes ir easier to understand? Why do you do that?
I do it simply because it feels pleasant to me. I'm sorry it's annoying for you, thanks anyway for your opinion maybe I'll do a survey.
@@nippocast thanks for engaging.
when creating the sound balance between narration and other music and effects (I speak as an ex-BBC sound engineer now in a different career) Do remember that you are totallyFamiliar with the concept you are explaining and of course totally familiar with the exact words of your script, so your brain can very easily Process what is being said above quite a high level of background interference.
But the layperson hearing your narration for the first time and maybe with their own background sounds wherever they are listening, will struggle much much more To understand what is being communicated. That's before any hearing loss issues are considered in your audience, or people who have a need to keep awareness of their immediate environment, in traffic or to hear someone calling for help in my case.
I can categorically state that in my 25 year professional career I was never asked by a producer to create a sound balance that is as difficult to hear as is the case in your video.
But I wouldn't even be bothering to make these comments if I couldn't find the content of your video extremely interesting as a complete layman when it comes to organs and thank you for the incredible amount of work that you have put into this.
Cheers.
@@__Andrew_ Interesting to hear it happened to others too - I'm Tim Main's brother, who like you walked away from the BBC.
@Andrew abc Okay, interesting.
I'm always open to criticism, when it's constructive, because it allows me to improve the quality of my channel. Thanks for the info, I'll pay more attention to the balance between sound and narration in the future.