 The Clarinet BBoard
|
Author: MGarrison
Date: 2003-09-06 01:29
I have just moved from Vancouver (coast - temp low to mid 20s) to Kelowna (inland - upper 20s and low 30s) in British Columbia. In Vancouver I regularly played in band and piano accompaniament.
I have never had problems with tuning, usually making very slight adjustments to play with the piano or the band.
Since moving to Kelowna I am now incredibly sharp. Most notes are at least 25 cents sharp but some are as high as 40-44 cents sharp (in the throat tones).
Would the temperature really account for this change or could it be something else?
My clarinet is a Leblanc Noblet 27. I am playing a B* Selmer mouthpiece with Vandoren lig and Vandoren 2 1/2 reg reeds.
Marina
|
|
Reply To Message
|
|
Author: moose6589
Date: 2003-09-06 02:13
it seems highly doubtful that the weather would cause you to be extremely sharp. That's because once you warm up, and the instrument is warm, it doesn't matter where you're playing, because the instrument's always the same temperature, about. It may just be the reed changing because of temperature, or something, I'm not sure. I recently started playing very flat for a change, for no particular reason, and the next day, it was fine. Why? I have no idea. but if you can't fix the problem, perhaps buy a longer barrel or pull out more if possible.
------------------------------------------
Post Edited (2003-09-06 02:14)
|
|
Reply To Message
|
|
Author: ginny
Date: 2003-09-06 05:02
I had a bout of playing sharp a few weeks ago. I had not been playing much and got back to biting.
|
|
Reply To Message
|
|
Author: Gordon (NZ)
Date: 2003-09-06 14:54
I would definitely suspect the air temperature.
This can happen in amateur theatre where lighting heats the pit and there is no air conditioning.
Are you able to find a cool (air conditioned? - butcher?) place to check whether the tuning comes right again?
|
|
Reply To Message
|
|
Author: MGarrison
Date: 2003-09-06 16:08
There is an elevation difference - sea level vs 344m (1129 ft).
As for batteries for the tuner, both my tuner and my instructors tuner noted the same problem.
|
|
Reply To Message
|
|
Author: Wes
Date: 2003-09-06 18:09
One sometimes sets the tuner to A430 by mistake instead of A440.
|
|
Reply To Message
|
|
Author: Dee
Date: 2003-09-06 20:47
moose6589 wrote:
> it seems highly doubtful that the weather would cause you to be
> extremely sharp. That's because once you warm up, and the
> instrument is warm, it doesn't matter where you're playing,
> because the instrument's always the same temperature, about. It
> may just be the reed changing because of temperature, or
> something, I'm not sure. I recently started playing very flat
> for a change, for no particular reason, and the next day, it
> was fine. Why? I have no idea. but if you can't fix the
> problem, perhaps buy a longer barrel or pull out more if
> possible.
You are incorrect. When the sound wave leaves the instrument, the pitch can change.
Here's a thumbnail sketch of how it works.
Speed of sound = length of sound wave x frequency of sound wave.
Therefore
Frequency = speed of sound / length of sound wave.
When the air temperature changes, the speed of sound changes. i.e. The speed of sound is dependent on the air temperature. Now the length of the sound wave is fixed by the geometry of your horn. So when the sound wave enters the different temperature air outside your horn, the frequency changes based on the air temperature. Changes in air density and pressure have the same type of effect since the speed of sound also depends on these parameters.
You can actually test this phenomenon if you like. Take a sound generator and set it to a certain pitch and listen to it. then jump in a swimming pool and complete submerge and have a friend outside the pool activate the sound generator at the setting. You will hear a different pitch even though it is being generated at the same level as before.
The reason you warm up the instrument before serious playing is so that you are generating a stable pitch. i.e. So it doesn't drift as you play. This way you can push or pull the barrel to get in tune under the prevailing conditions.
Clarinets are designed to be in tune at about 72°F. If the area you are playing in is much warmer, you will go sharp and have to compensate. If it is much colder, you will go flat and have to compensate.
Of course there are a myriad of other things that can cause you to play flat or sharp.
|
|
Reply To Message
|
|
Author: Gordon (NZ)
Date: 2003-09-06 22:18
I fully appreciate that your formulae apply to the relationships between parameters when the sound is being crated, i.e. within the air column, and I know my knowledge is limited, but I find your example difficult to take in.
Think about it. Say your sound generator generates the sound by a diaphragm whacking the air 440 times per second. 440 pulses hit the water surface each second. 440 pulses travel through the water every second. 440 pulses hit my ear drum every second. Hence same pitch.
If that is too difficult to grasp, then think about a different, slower generator, say a person (or wave machine) whacking the water at a frequency of 10 slaps per minute. It operates for one minute. 10 slaps. How could the underwater person possibly detect 9 or 11 slaps during that minute. How could it be different? Where would extra pulses come from?
I think that what happens is that the pulses travel through the WATER at a faster speed and longer wavelength, such that the frequency is unaltered.
Surely it is only the temperature of the air inside the bore that is significant. Perhaps somebody else can explain if my logic is faulty.
And I don't believe that a clarinet reaches anywhere near body temperature a cold room. I know this because my clarinet is much flatter in a cold environment when I am playing softly for a long period, ie when the quantity of breath passing through the instrument is insufficient to warm the air column at all, especially the lower half of the clarinet which has plenty exposure to the outside cold air via tone holes and the bell. Therefore a warm environment would surely make quite a difference to bore temperature.
|
|
Reply To Message
|
|
Author: Mark Charette
Date: 2003-09-06 22:33
Gordon - the clarinet is a closed resonant system. You're right - 440 cycles/sec is the same, on Earth, Jupiter., and Mars ...
But the frequency at which a closed cylinder driven at one end resonates is a function of effective length, effective diameter, and the local speed of sound. If a tube resonates at 440 Hz for one set of conditions, it will resonate differently if one of the conditions changes; e.g., the local speed of sound is dependent on the density of the air, which is affected by pressure and humidity. Pressure is affected by temperature and altitude.
|
|
Reply To Message
|
|
Author: Gordon (NZ)
Date: 2003-09-07 02:48
I agree completely. But Dee, as far as I can see, was saying something quite different - that a note leaves the instrument at a given pitch, and then the density of the medium between the instrument and the listener is capable of altering that pitch for the listener.
|
|
Reply To Message
|
|
Author: Hank Lehrer
Date: 2003-09-07 02:59
Hi,
I had a off-line convesation with a BB member a couple of months ago and he said that standard temperature is about 72 degress and the pitch will rise something like 20 - 30 cents per about 8 degrees above that standard. I may be a little off on these numbers but the acoustics book is by John Backus and the formulas are on page 137.
HRL
PS In aviation, changes in temperature have a much greater effect on aircraft lift that changes in altitude. A parallel may exist here.
|
|
Reply To Message
|
|
Author: Mark Charette
Date: 2003-09-07 03:01
Hank Lehrer wrote:
> PS In aviation, changes in temperature have a much greater
> effect on aircraft lift that changes in altitude.
Until you get up over 90 angels ![[grin]](http://test.woodwind.org/clarinet/BBoard/smileys/smilie5.gif)
|
|
Reply To Message
|
|
Author: Gordon (NZ)
Date: 2003-09-07 05:05
"I had a off-line conversation with a BB member a couple of months ago and he said that standard temperature is about 72 degrees and the pitch will rise something like 20 - 30 cents per about 8 degrees above that standard. I may be a little off on these numbers but the acoustics book is by John Backus and the formulas are on page 137."
Well that would totally explain the problems encountered by the person who started the thread, even without angelic interference.
|
|
Reply To Message
|
|
Author: Synonymous Botch
Date: 2003-09-07 13:26
I just repeated reading of this thread...
40 cents sharp?
Something else is going on here.
344m isn't enough to make a tremendous density difference in the air.
I wonder if your clarinet is settling due to a real climate change?
Is your mouthpiece hard rubber?
Did your reeds suffer handling in transit?
I suspect one of these constituents has warped.
******
Are you changing your embouchure to play through the tears of separation from that glorious city?
|
|
Reply To Message
|
|
Author: Bob A
Date: 2003-09-07 17:31
Has all the smoke cleared away from Kelowna as yet? I understand there was a major flash-fire and 244 houses were destroyed. Would breathing smoke filled air alter your air column and that cuse a problem? Grasping and gasping!.
Bob A
|
|
Reply To Message
|
|
Author: Gordon (NZ)
Date: 2003-09-07 22:43
Synonymous Botch wrote "344m isn't enough to make a tremendous density difference in the air."
No, but a 10 degree increase in temperature could be.
|
|
Reply To Message
|
|
Author: Hank Lehrer
Date: 2003-09-07 22:56
I'll try to get by the library at work tomorrow as I know the university has that book and will let you know.
Mark, above 90 angels, everything changes. It has been a while since I did much aerodynamics work so pardon the lack of solid numbers (I don't even know where my books are).
HRL
Post Edited (2003-09-09 19:27)
|
|
Reply To Message
|
|
Author: MGarrison
Date: 2003-09-07 23:15
Here's some more info:
Is your mouthpiece hard rubber? Selmer B* (also tried Selmer HS* - my spare)
Did your reeds suffer handling in transit? I have tried my usual Vandoren 2.5 as well as some Mitchell Lurie 3. Same thing with both. All reeds were brought to Kelowna from Vancover and have been stored in their plastic cases.
While smoke is still around (especially yesterday - when it looked like a heavily polluted day in LA) I am playing indoors where I have an air purifier running 24/7.
If the temperature makes such a difference, how is it that my instructors clarinet is more in tune than mine at the same temperature? While it is a different model, surely if all clarinets are designed to be in tune at 72F then wouldn't there be similar distortions as the temperature rises?
|
|
Reply To Message
|
|
Author: Mark Charette
Date: 2003-09-07 23:56
Hank Lehrer wrote:
> Mark, above 90 angels, everything changes (probably lower as
> the lapse rate really begins to tail off dramatically ).
The reason 90 angels sticks in my mind was that was themore or less) normal altitude for the U2 recon plane. Anything higher than that needed attitude control jets.
|
|
Reply To Message
|
|
Author: Hank Lehrer
Date: 2003-09-09 13:34
Hi,
I went to the libray and got Accoustic Foundations of Music by John Backus, W.W.Norton, 1977 and on page 156 found the following information. "A rise in temperature will flatten the strings. On winds and brass, however, the increased speed of sound at higher temperatures produces a considerable increase in pitch. It amounts to 3.0 cents for each degree Celcius (1.6 cents for each degree Fahrenheit)."
So, it looks like a 10 degree increase in C will raise the pitch 30 cents. I could not find the mention of standard temperature but my recollection is about 72 degrees F. I assume the manufacturers use something like this as a benchmark
Interesting book. Fascinating physics.
HRL
|
|
Reply To Message
|
|
Author: supernova_khr
Date: 2003-09-09 15:39
Ok, this is way off topic, but since it was mentioned above...what kind of unit is an "angel" (other than a heavenly being with wings?) I do flight plans for high altitude airplane pilots, but have never heard that term. The U2 (or ER-2) flies at 60-70 kft (or up to 50 mb in pressure), with and with the current engines can go a bit higher. Its cruise pitch angle is less than 10 degrees, so I'm assuming you're not talking about 90 degree angles. Its takeoff pitch angle is on the order of 30 degrees. (I've spent 3 summers and one SH winter working on NASA multiple airplane experiments including one of the NASA ER-2s, so that's the only reason I know about it.)
Anyway, at those levels, the plane is in the stratosphere, with a lapse rate that increases with height. It flies at nearly constant mach, so true air speed changes as temperature and pressure change.
Cheers,
Kay
|
|
Reply To Message
|
|
Author: Bob A
Date: 2003-09-09 15:47
"Angels" = WWII Fighterpilotspeak, for thousands of feet. "Bandits heading 230 , Angels 27, Buster"
You've missed all the good midnight movies or are not a "geezer" like Mark C , Hank and I (heh! Heh! Heh!).
Bob A
Post Edited (2003-09-09 15:52)
|
|
Reply To Message
|
|
Author: supernova_khr
Date: 2003-09-09 16:07
No, I wouldn't classify myself, or the pilots I work with, as geezers. I'm a lowly physicist, and they're Vietnam era and later military pilots. They want to hear things in flight levels, not angels. (Angels 27=Flight level two-seven-zero). That's what ATC wants too.
Thanks for the info,
Kay
|
|
Reply To Message
|
|
Author: Hank Lehrer
Date: 2003-09-09 16:53
Hi Supernova,
You need to see 12 O'Clock High or one of the other WWII aviation action movies that we old geezers would pay 15 cents to see at a Saturday matinee. And some popcorn if we were really flush.
True, all flights above 18,000 ft are at FL with a reset of the altimeter to 29.92 (which you know, I'm sure). Lowly physicist, indeed. I love physics (almost as much as the bassoon).
HRL
Post Edited (2003-09-09 19:26)
|
|
Reply To Message
|
|
Author: Bob A
Date: 2003-09-09 16:54
Yeah, I know Kay. Included in my many sins is the fact I was an Air Traffic Control dingbat for 344 plus years.
Bob A
|
|
Reply To Message
|
|
Author: Bob A
Date: 2003-09-09 17:41
"Sorry 'bout dat". I feel really old today. Should be 34.4 years not 344.
Bob A
|
|
Reply To Message
|
|
The Clarinet Pages
|
 |
.jpg){kind=small}
.jpg){kind=small}
.jpg){kind=small}
.jpg){kind=small}
.jpg){kind=small}
.jpg){kind=small}
