 The Clarinet BBoard
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Author: willie
Date: 2001-12-13 20:07
The thread on "helium" got me to thinking. How would the different conditions of the air conditions at various sites effect tone and tuning? For instance, here in S.E. Texas, the air is warm, 90% humidity and at sea level. In Denver, you are a mile high, much less humidity, and nowhere near as warm.
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Author: Francesca
Date: 2001-12-13 21:32
I can't tell how much effect conditions actually have on playing. I just moved to the Denver and certainly noticed a difference in my tone, but that could be mostly due to the lack of oxygen around here. I did seem that my good reeds never did sound the same as when I was home (about 2000 ft. elev.) Anybody else notice a difference?
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Author: Me
Date: 2001-12-13 22:47
I've noticed that when I'm in the mountains the air is drier and I usually have to use softer reeds. I hadn't really noticed a difference in tone, thought.
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Author: Hiroshi
Date: 2001-12-14 01:13
If air is drier, the sound reaches far and resonate better.
If air is hotter, the pitch becomes higher.
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Author: Emms
Date: 2001-12-14 09:54
But if everyone plays under the same conditions, surely everyone will be affected in the same way. May be a problem if someone in Texas is playing a duet with someone in Denver ;o}.
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Author: William
Date: 2001-12-14 14:19
Here's a thought--as the conductance of air waves are affected by varying atomopheric conditions--temperature, humidity, pressure, etc--perhaps it is not so much our instruments and reeds that are affected but rather our perception of the environmentally altered sounds reaching our ears. I have experianced "sudden reed failure" haveing noticed changes in my sound just traveling to a different location within my own state. We all know what difference a concert hall compared to a practice facility can make. Why then, not a complete change in environmental atmospheric conditions and their inevitable effect on how sound travels through the air? Makes speculative sense to me--how about any of the environmental engineers on this web site who might also be clarinetists--is this a valid assumption, or just more "hot air?"
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Author: Ralph Katz
Date: 2001-12-14 16:28
Automatic helium injection could just be our solution to string sections that habitually play sharp. (ha!)
Seriously, pitch is effected by air density - the denser the air, the lower the pitch, and vice versa. Think of it as increased air mass vibrating slower.
A few years ago I got roped into playing an outdoor wedding in Flint, Michigan in November. It couldn't have been more than 45 degrees, and there was nothing I could do to bring my pitch any closer than 1/4 step below where I should have been. The mandolin could lower the pitch but the accordion could not. This actually worked out well for us, though, because I was then free to keep the sheet music and stand from blowing away.
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Author: Don Christman
Date: 2001-12-15 03:11
Getting back to the altitude issue, I have lived in West and played woodwinds in several high altitude and low altitude sites from sealevel to 9000' over the years.
The major factor is low humidity. The absolute humidity is so low at 9000' it has perciptible effects on reeds and all wooden instuments from clarinets to violins.
One can hardly keep a reed moist enough; even while playing it dries out!
The wood will shrink and tenon rings will come loose.
However, the low air density has noticeable consequences also. Primarilly, it is difficult to play long phrases, especially on flute, because of diminished lung capacity, even after adapting to living at altitude.
And the actual density of the air decreases geometrically with altitude, especially noticeable beyond 5000'. In my experience this makes the air column in the horn less controlable, yielding a less rich sound. Others have expressed the opinion that it is the other way around. But take note that sound travels slower at high altitude, as it is a less dense medium as atmospheric pressure decreases. On the Moon you couldn't play a clarinet at all. On a cool morning in Death Valley, California you should be able to produce the richest, densest sound.
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Author: Dave Beal
Date: 2001-12-15 15:31
The speed of sound in air is dependent only on temperature. It's proportional to the square root of the absolute temperature, so it travels at the same speed on a 50 degree day in Denver as on a 50 degree day in Seattle.
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Author: Don Berger
Date: 2001-12-15 23:32
This seems to be a fine follow-up to our helium discussion, and I read the comments of Ralph, Don C and Dave with "scientific interest" !! My only addition is the experience of playing bari sax in a "big band" in Silverton CO, el. 9300!! , I didnt concentrate on tone quality, I was just too busy gasping for breath. Don
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Author: Gordon (NZ)
Date: 2001-12-16 11:38
Dave Beal: Is that strictly true? Just to confirm.... same speed at 50F in compressed air as 50F in rarefied air.
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Author: Mark Charette
Date: 2001-12-16 15:53
Geez - I meissed this. Dave - where'd you come up with <b>that</b>? Speed is determined by the formula:
v = sqrt( <b>B</b> / <b><i>p</i></b>)
where <b>B</b> is the bulk modulus of the elasticity of the medium and <b><i>p</i></b> the density.
There are temperature calculations to be done to determine density, but there's pressure calculations as well. Using the Ideal Gas law:
<b><i>p</i></b> = <b>P</b> / ( <b>T</b> * <b>R</b> )
Where <b>P</b>=pressure, <b>T</b>=temperature, and <b>R</b> the gas constant (about 287 for air). Temperature or pressure would also undergo corrections to accomodate the changes wrought by humidity (the density of humid air is less than that of dry air).
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Author: Don Christman
Date: 2001-12-16 17:28
Thanks Mark on the air density follow-up. Your formulae help defend my earlier position that sound travels slower at lower densities/higher altitudes.
A case in point: Mach speed, or the sound barrier, is not the same at sea level as at higher altitudes. Mach I is higher at sea level in the denser atmoshpere and decreases with altitude; that is, the "sound barrier" is variable with atmospheric density, as are the sonic characteristics generated by a wind instument.
There would be a point at which there would be so little density in the air column within a clarinet that virtually no sound would be produced. That point may be at 50,000', but my point was that at Leadville, CO at 10,200' there is a noticeable difference in wind instrument performance.
Would anyone like to volunteer to play clarinet in a pressure/vacuum chamber to settle this question? You may die at the end of the experiment, but you would be remembered fondly for your contribution to acoustic research.
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Author: Mark Charette
Date: 2001-12-16 17:43
I believe Dave may have been misled by some formulae which compute an approximation of the speed of sound vs. temperature <i>at standard pressure</p>; e.g., standrad pressure as calulated at sea level.
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