 The Clarinet BBoard
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Author: Phil84
Date: 2023-08-22 15:28
Hello, is there an explanation on how the altitude above sea level and the umidity affects the clarinet reed? Maybe it's been discussed in another topic?
Best,
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Author: Fuzzy
Date: 2023-08-22 19:48
Hi Phil84,
Are you refering to scientific study or just personal experience?
Fuzzy
;^)>>>
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Author: Fuzzy
Date: 2023-08-22 21:18
Thanks Phil84 - personal experience, I can offer!
I live above 7200 feet in elevation (roughly 2220 meters) in a very dry climate (11 inches of rain per year). I've found that whenever I go play in New Orleans, New York, or California...that I must increase my reed strength by anywhere from 1/2 step to full step. Especially New Orleans and New York. I don't fully understand why it works that way, but after several frustrating experiences I finally discovered the move to harder reeds at sea level/high humidity keeps the playing experience even, or "normal" for me. If I remain on my "normal" strength reeds, I fight flatness in tone.
Others in my region have found the same thing to be true through their own experiences.
I know most/many folks (who come from lower elevations to play concerts here, at elevation) end up going through a lot of reeds. (Wynton Marsalis' group played at the local university a number of years ago, and though I can't remember whom the reed player was - he turned the destruction of his "bad" reeds into performance art throughout the masterclass and following concert.) I believe he would have been better served simply going down 1/2 step in strength - as I'm relatively certain that he demolished a great number of reeds which would have played well back in NYC.
At the same time, I've known other players who come from New Orleans or New York to play here and they just keep their usual reed rotation if the gig is only a day or two in length.
Fuzzy
;^)>>>
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Author: Paul Aviles
Date: 2023-08-22 22:14
Great personal experience on the effects of barometric pressure!
I’d only add that low humidity (below 50%) can make reeds play harsher or even not at all.
………….Paul Aviles
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Author: Claudia Zornow
Date: 2023-08-22 23:14
I wonder whether the reeds themselves actually change at higher altitude, or if the perceived difference is because of the lower density of the air going through the reed/mouthpiece/clarinet. Does anyone know?
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Author: Fuzzy
Date: 2023-08-22 23:30
Claudia,
I don't think it is the reeds. I would think it has something to do with the density of air. (Thin air, lighter reeds; thicker air, harder reeds).
Likewise, I think (a least in my case) humidity plays a role too.
Fuzzy
;^)>>>
P.S. - What I find odd...is that the harder reeds at sea level play with the same (or less) effort than the softer reeds at elevation. I would have thought it should be the other way around.
[EDIT: added P.S.]
Post Edited (2023-08-22 23:37)
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Author: Fuzzy
Date: 2023-08-22 23:48
One additional thought:
There's an article by Stephanie Zelnick here which discusses a sort of experiment she and Dr. Lauren Jacobson performed.
Dr. Jacobson notes that her embouchure leaked air above 13,000 ft. I chalked this up to the thinness of the air, and the strength at which she was accustomed to blowing. However, wouldn't the air inside the person be at the same thinness as the air outside the person? Wouldn't the effort match?
Beyond my own experiences, my knowledge is extremely lacking in this area, so I'll leave it to others - though I'm interested to understand the what/why/how.
Fuzzy
;^)>>>
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Author: Paul Aviles
Date: 2023-08-23 01:28
It's air pressure in general. Same reason why eggs boil faster in Denver, or why mountain climbers unaccustomed to high altitudes can actually suffer debilitating altitude sickness.
It's not just reeds
............Paul Aviles
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Author: Fuzzy
Date: 2023-08-23 02:22
Paul,
"Why eggs boil faster in Denver" made me chuckle. Compared to where I live eggs boil slower in Denver.
I understand your point though.
I do understand that air density plays a role, but why do the differences present themselves the way they do around a reed/body/clarinet system?
I would think (and perhaps this is where I'm wrong) that the air density inside the human body would be in the same proportion to the air outside of the body - regardless of elevation/density.
A person only needs to go shopping once at altitude (and once at sea level) to see a huge difference in the atmospheric density/pressure. At sea level the snack bags are mostly slack, and the pringle cans are concave, etc. In my home town, folks should probably wear eye protection as they approach the snack isle where everything is stretched tight and on the verge of bursting, the bags are so tight that you almost can't pinch them to pull them apart, and the pringle cans are so convex that the plastic tops are often disloged.
Baking takes far less yeast, requires modified temperature and baking times, and making candy requires a special knack as the temperatures are all much lower than the recipes indicate, etc.
Our gas stoves must be modified to operate above 4500 feet, etc.
So, yes, living at any altitude above 3000 feet or so does require some basic understanding of the pressure difference...but this instrument/reed/body thing still doesn't make total sense to me.
I would think that in denser air, with a harder reed, a person would feel like they were blowing harder to produce the sound...but that's not the case. It usually feels easier. Perhaps there's a break point at some spot (say, for instance, 2000 ft) where playing at sea level on a harder reed WOULD feel more difficult?
Like I said - a bit of a mystery to me.
Fuzzy
;^)>>>
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Author: Paul Aviles
Date: 2023-08-23 03:08
Sorry, it is the boiling point of water that decreases!
Sorry for the error.
............Paul Aviles
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Author: elmo lewis
Date: 2023-08-23 06:52
My personal experience: I live at 4350 feet and often play concerts at sea level and at 7300 feet. A common occurence is a Thursday morning dress rehearsal at 4350 feet, a Thursday night concert at sea level, and a Friday night concert back at 4350. We sometimes do a Friday night concert at 4350 and a Saturday night concert at 7300. All travel is by bus. None of the concert halls are heated. Sometimes the air-conditioning is working but sometimes it isn't
I can feel the difference in the air-it's much thicker at sea level. I can play longer phrases without difficulty. The air is also more moist at sea level, even though the relative humidity at 4350 is usually between 70% to 80%.
A reed that is too soft at 4350 will be way too soft at sea level. If it is a little stiff at 4350 it will work fine at sea level. Even a warped and unresponsive reed at 4350 will often open up and become playable at sea level. It is much easier to make a clean attack at sea level, the instrument seems more responsive, playing is effortless.
At 7300 even a soft reed sounds dry and pinched. The air is extremely dry, it is difficult to keep the reed wet, dry mouth is often a problem. If it is a one-day trip the instrument and the player don't have time to dry out. With a longer stay, playing is more difficult because the instrument changes as it dries out and the human body also begins to adjust to the low humidity.
I think there are 3 variables: the air pressure or density, the air temperature, and the humidity. These are interrelated as warm air holds more moisture than cold air.
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Author: Dan Shusta
Date: 2023-08-23 11:46
Phil84, I know that you wanted answers from experienced players and that I am not.
I have, however, composed what I consider a logical explanation which, I believe, would enhance everyone's understanding.
I really don't want to hijack this thread by going off topic so I'll leave it up to you if you would like to read it.
Post Edited (2023-08-23 11:57)
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Author: Luuk ★2017
Date: 2023-08-23 14:30
A quick look into some physics books learns me that the speed of sound (and thus the frequency) is influenced by temperature, and to a lesser degree by pressure. And, maybe surprising, humidity has an influence on frequency dependent damping, not on frequency itself.
The speed of sound in air v (m/s) as function of temperature T (C) is given by
v = 331.5 + 0.6 T
Here we see that v changes in a linear way with temperature, which is an important effect, but for this discussion I will focus on pressure and humidity, and assume that temperature is constant.
Now v in a gas is depending on its pressure P (Pa) and its density d (kg/m3).
v = (square root (1.4 P)) / d
But the density of a gas is also proportional to pressure:
d = P / RT
where R is the specific gas constant and T is, of course, temperature.
Combining the last two equations gives us
v = (square root (1.4 P)) / (P / RT) = ((square root (1.4 P)) RT) / P
This means that the speed of sound increases with the square root of the pressure, but it deminishes in a linear way with the same. In the end, the linear dependency will win from the square root and thus v will decrease with growing pressure: sound goes slower at sea level because air is more compressed there.
Now frequency is defined by f = v / l, where l = wavelenght (m).
Let's assume a clarinet does not change it's length when pressure is changing. Thus, the wavelength is always the same for the same fingering. However, since v changes with pressure, f is also changing, according to the last formula. With increasing v we will get increasing f. And we have seen that v decreases with P. Thus, the frequency should become lower at higher pressures (= lower altitudes).
I have filled in all constants in the equations, and a comparison of the frequency of a given wavelength at different heights above sea level yields:
f @ sea level = 100%
f @ 1000m or 3280 ft = 106%
f @ 2000m or 6561 ft = 113%
f @ 3000m or 9842 ft = 120%
This means a clarinet which is tuned at sea level, will be about 5% too high at 3000ft, which is somewhat less than a half tone. This result seems too large to me, but it indicates there should be a remarkable effect.
Now humidity only has a very small effect on frequency (think about 0.3% when going from 0 to 100% RH), but it does influence damping. The interesting part is that this damping depends on frequency, working in such a way that higher frequencies are damped more than lower frequencies. I have found no simple formulas to explain and/or compute this effect, but I found lots of graphics on the internet illustrating this (for instance https://www.engineeringtoolbox.com/air-speed-sound-attenuation-humidity-frequency-d_2161.html or https://ebrary.net/134853/environment/absorption). In the end, the effect is that dry air makes the sound more bright, especially over large distances.
Of course all this is at best half the story: there is no mention of a reed or a human body. But these formulas may offer part of the explanation.
Regards,
Luuk
Philips Symphonic Band
The Netherlands
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Author: Hunter_100
Date: 2023-08-23 18:24
my view on the matter, possibly very wrong:
The reed opens and closes from the flow of air going past it. It is sort of like the lift force an airplane experiences. Low density air at altitude has less "lift" (both for air plane wings and for closing force for the reed), so you have to blow faster air to get it to oscillate (i.e., the reed feels harder). Dense air at sea level has more lifting potential, so you can blow slower air with the same reed.
To compensate for these effects, you can use harder reeds at sea level and softer reeds at elevation.
Humidity increase from the local weather causes air pressure to drop, which is just like going to higher elevation.
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Author: Dan Shusta
Date: 2023-08-23 19:18
Since it appears that the thread has gone astray from the OP's request of only player's experiences, (by the introduction of physics), here's my strictly logic explanation:
When playing at 7000 feet, the air is quite thin (less oxygen) and therefore it has less weight. A thinner reed is necessary because when the player exhales his or her stream of air, due to the light weight of the airstream, the reed is actually “hit” with a smaller or lighter impact. With a harder reed, the player’s light weight airstream would “hit” the reed too softly for it to vibrate correctly.
At sea level, the air is much denser (more oxygen is available) and therefore much “heaver”. A stronger reed would be required because the exhaled air stream from the player would also be heavier and therefore would cause a much greater “impact” against the reed. Too soft a reed would probably either just “close up” or produce a flat tone.
The player would experience a similar playing experience either at sea level or at 7000 feet because the proper strength reed would produce the same “feel” to the player.
I’m convinced that it all has to do with the “density weight” of the players exhaled airstream.
All of the above is simply my logic opinion.
And, all of the above sure sounds logical to me. Feel free to correct me if you think I’m wrong.
I found the following article after I had already written my logic explanation.
Air density varies with altitude https://www.engineeringtoolbox.com/air-altitude-density-volume-d_195.html
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Author: Luuk ★2017
Date: 2023-08-23 19:24
Hi Hunter_100.
The reed opens and closes because there is a standing wave in the clarinet bore. The airflow is only needed to put energy into the system. Can you explain your airplane analogy?
What do you mean with 'faster' air? More pressure? Maybe you are thinking that 'more dense air' has more 'pushing power'. Well, I don't know what you exactly mean, but it may be right. But we are discussing a very complex mechanism with lots of variables. For instance, Elmo Lewis writes he can play longer phrases at sea level. Maybe this is because the oxygen level at high altitude is lower so his body is asking for more air. I don't know.
In the end, I think that the energy you have to put into the system to get it 'running' should be the same in all cases.
To me, it is still not clear how environmental air pressure or humidity would cause a need for lighter or heavier reeds, except what I worked out above: at sea level a clarinet will tune lower than at high altitude, which may be remedied by using heavier reeds at sea level. This leaves some of the observations of Elmo and Fuzzy unexplained for me at least. Maybe they can elaborate on the described need to change reeds. Why is that? Because of stamina, sound quality, something else?
And, I would be very interested in any references for your statement that humidity causes a lowering of air pressure.
Regards,
Luuk
Philips Symphonic Band
The Netherlands
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Author: Hunter_100
Date: 2023-08-23 19:35
Air moving past the reed creates a force imbalance so the reed closes. but the force causing the reed to close goes away when the airflow is cut off, so then the reed opens again. This creates the vibrating of the reed. The actual frequency of the vibration is from the standing waves set up in the bore as you describe. In my analogy the force that is closing off the reed is similar to lift created from air moving under an airplane wing, since you have moving air on the one side of the reed and stagnant air on the other side.
The drop in pressure from humidity is a well established weather phenomenon. Adding water molecules to an air mixture lowers it's mass because water molecules are lighter than N2 and O2 molecules.
Post Edited (2023-08-23 19:52)
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Author: Julian ibiza
Date: 2023-08-23 23:06
When we speak of 'atmospheric pressure' , we are effectively talking about different densities of air molecules. Wind force is not just the velocity of the those molecules, but also relates to their concentration. Thus a plane flying at a given speed encounters less air resistance as it climbs in altitude and the air becomes more rarified.
When we blow, we create an air pressure within out lungs, but a lung full of air at sea level has a greater concentration of air molecules than at higher altitudes.
I hope this has something to do with anything. Ha-ha!
Julian Griffiths
Tel. 34 696 798 853
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Author: Dan Shusta
Date: 2023-08-24 00:34
Julian,
I find your post above to be absolutely correct. The greater concentration of air molecules at sea level, to me, simply means the air is more "dense" and has more molecular weight. This then means that a player blows a more powerful airstream because of the greater density or molecular weight which in turn requires a reed to be harder or the reed will close up if it is too soft.
At much higher altitudes, the density of the air molecules is more spread out or less dense resulting in a lower molecular weight. This would necessitate a softer reed due to the softer or less dense air stream force being blown from the player.
This makes sense to me.
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Author: Julian ibiza
Date: 2023-08-24 16:43
Temperature also affects the molecular density of air. The higher the temperatures....and lower the density.
Julian Griffiths
Tel. 34 696 798 853
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