 The Clarinet BBoard
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Author: Mark M
Date: 2002-09-16 04:06
Just sitting here with a glass of wine (or few) and thought I'd start a thread concering temp. Everyone has had problems playing a Bb and an A (different times) during a rehearsal/performance and the instrument on the stand goes out of tune due to temp. In my case, it's a Bb/A/bass. ie. The back stage door opens in 20 degree temp etc etc., and you know the rest of..... Has anybody out there thought of manufacturing a clarinet stand that has something like a pad saver going up the bore with a SMALL heating element connected to a battery and overtemp sensor? You could spin the horn and clean the bore and keep it at a prescribed temp while on the stand. It can be battery powered because it only has to last a few hrs and within that few hrs, it shouldn't overheat the horn due to the overtemp sensor and battery life. With todays electronic technology with chargers and types of batteries (rechargeable) available, I know it can be done. My expertise is in the aerospace electronics area, but just don't have the time to tinker with such with employment and house remodeling that is ongoing. Perhaps in 2-3 yrs though.......
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Author: Robert
Date: 2002-09-16 08:39
I know that Ian Holloway, pricipal clarinetist of the KZN Philharmonic in South Africa, has built such a device. His email address is on the orchestra website:
http://www.kznpo.co.za/
Maybe email him to ask about it?
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Author: L. Omar Henderson
Date: 2002-09-16 12:58
Ah-the famous pit syndrome and temperature effects. I am a gaget-ter loving sort of breed and your ideas are intriguing. Want a Beta tester? Actually, I bought one of the Alteri Bag Co.'s clarinet mufflers at Clarinetfest. It is a highly insulated tube that you slip over a "warmed up" horn and just slip it off when the need arises. One could make their own with scavenged stuff. Cold temperatures can cause a number of ill effects on horn performance -now if one could envision an cooling coil for the heat on a summer band stand you have a dynamic duo. It has been just a "tough it out and move on" affair for most.
The Doctor
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Author: Don Poulsen
Date: 2002-09-16 14:08
But is the intonation change due to the thermal expansion/contraction of the instrument or to the change in density of the air within the instrument?
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Author: L. Omar Henderson
Date: 2002-09-16 14:28
Don - Physics is great for those knowledgable in the field and I will not go there too far. I think that it is more likely the effects on the instrument than the density of the air. One thing for sure is that there is a rapid accumulation of moisture blowing warm air into a cold horn - this moisture may cause cavitiation currents and change the tone-intonation. From my calculations the density change in air at 50 degrees F and say 75 degrees is not that great and other factors probably cause greater effects. One thing for sure is the fact that the player is uncomfortable in fighting off the chills which may affect the contortion of the "chops".
The Doctor
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Author: Ken Shaw
Date: 2002-09-16 15:10
Omar -
How does a clarinet respond in the Altieri bag? Is it the long-sought clarinet practice mute? I'd dearly love to be able to practice at odd hours and not bother my wife or neighbors. When I posted a query about a month ago, another bag manufacturer replied to say that a sax felt much more resistant in one.
Best regards.
Ken Shaw
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Author: L. Omar Henderson
Date: 2002-09-16 17:55
Ken - The bag as now constructed is too small to get one's hands inside so I do not know!
The Doctor
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Author: JMcAulay
Date: 2002-09-16 18:48
Mark_M: Changing the temperature of any substantial mass by a few degrees involves considerable energy, so I suspect your battery would be pretty large. Also, radiation from a thing inserted into the bore would work okay, but perhaps forced convection with air blown over the warm side of a Peltier cell and up into the instrument would be desirable, especially as the cell could be reversed to cool the instrument in accord with Dr. Henderson's wishes.
General Electric built some samples of a baby-bottle cooler/warmer something like 40 years ago, but I believe it never was sold commercially. A Peltier cell (they were fairly new and very expensive then) kept the bottle refrigerated until shortly before feeding time, when the cell operation was reversed by a change of polarity of applied violtage, and the bottle was brought up to 37ºC/98.6ºF. "Too costly for its day" was my understanding of why it wasn't produced in quantity.
Regards,
John
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Author: Dee
Date: 2002-09-16 21:23
Some time ago, I posted a calculation of the thermal expansion and contraction of a clarint. The change is so small that it will not induce intonation changes or any significant physical stresses in a clarinet.
The intonation changes are due to the changing density of the air, which is a function of both temperature and humidity.
The cracking that one sometimes sees in wooden instruments is more likely due to humidity effects. The expansion and contraction due to this is quite noticeable.
The greatest hazard to instruments being used outdoors are actually things like being dropped or being knocked over.
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Author: JMcAulay
Date: 2002-09-17 01:23
Pressure (barometric) is also an important element of air density. That's why retuning is in order when playing at a significantly different altitude. One concern with wooden Clarinets outdoors should be cold weather, as the instrument may develop a severe crack at around 4ºC/40ºF due to expansion of cellular and interstitial water. As Dee says, humidity variations can result in noticeable changes in the Clarinet's size, especially as it becomes dry and the tenon socket rings tend to fall off.
Regards,
John
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Author: Mark M
Date: 2002-09-17 06:03
Well, I might be missing something here. I know all about the effects of temp, altitude, humidity etc on air density since I'm in the aerospace business. I have some really basic questions though. 1) If I'm 50c flat when I first start out blowing a horn, and, I come into tune after 5 min. of playing, and the air out of my lungs have not changed in temp, altitude, humidity, why does the horn come into tune? Im in the Seattle area so the ambient humidity is not dry by any means!! 2) If I'm 50c flat with a cold horn, why does it come into tune when I only warm it up for 10 minutes with my hands when all the air density parameters are the same? I agree that over time, humidity will change things as it affects air density. But, in only 5-10 minutes of time? To address John's issue of energy, this device would only serve to stabilize an already warmed up horn for a short amount of time. So, the caloric change is no where near what it would be if I wanted to actually warm it up with a device. A convection system would involve a fan. Battery killer. I'm a serious advocate of the KISS principle.
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Author: Bob
Date: 2002-09-17 13:59
Wow...a really interesting exchange. Here's a few of my thoughts:
1. Doesn't the condensation change the bore diameter?
2. I made a "sock" for my horn out of the velcro backed imitation fleece that was on my wife's replacement knee exerciser. It not only helps insulate the horn but is protection if it gets knocked over.
3. Years ago when I worked for G.E. I was involved in a few projects that were never commercialized either. Included among which was a non-fogging shaving mirror.
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Author: John Moses
Date: 2002-09-17 14:07
I have a much different take on this cold/hot intonation problem.
I've been playing in Broadway pits for 25+ years, and on cold record dates for over 20 years, also in hot orchestra halls, and in frigid marching bands.
I've tried the warming bags and even a heated peg for my clarinet, nothing really works well.
I suggest practicing in varied conditions, that is:
play at home in a cold air-conditioned room (really cold), use a tuner and see how far you must push in, or use shorter barrels, to get up to pitch.
Then play in a very warm room at home, say over 80 deg., and see how far you must pull out.
These adjustments, along with a good ear for change, will give you a range of change necessary for most adverse playing situations.
The real question is: do you have a well trained ear? Almost any adjustment will improve your intonation, if you know which way to go. Are you sharp or flat at that moment?
A young student many years ago asked to study with me, I asked what were his problems in playing the clarinet. He informed me he really needed help with his "tonation", so we worked on knowing the right word and then solving his problems.
Good luck with all the new devices, I'll try them all, but nothing helps as much as a good ear and constant adjustments to changing conditions.
JJM
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Author: L. Omar Henderson
Date: 2002-09-17 14:12
I knew that we would get around to oiling sooner or later - why you say? Plant derived oil binds water in a tiered fashion - the first monomolecular layer is tightly bound, with successive layers being less tightly bound. With the proper oil content in the wood there is virtually no free water and the freezing point - expansion is greatly lowered due to the oil-water interaction (the old freezing point depression, boiling point elevation chemistry lesson with a twist).
With changes in humidity there is also much less expansion and contraction of the wood because it takes a lot of energy to remove the water of hydration of the oil molecules. An instrument with the proper amount of oil in the wood will therefore resist rapid expansion and contraction due to changes in humidity. Over time of course in a extremely wet or dry situation there will be appreciable changes in the water content of the wood - but highly buffered by the interactions with the plant oil and much less than wood that does not have this capacity or a dimished capacity.
The same proceedures used to stabilize reed performance - keeping them in a narrow moisture range in storage should be applied to your horn. In this way the buffering potential of the plant oils is at a maximum when you expose your horn to hostile environmental conditions.
I hope that I am not being too monolithic in advocating proper oiling but it does help IMHO to control some of the elements that may alter the intonation of the horn. The other posts display a much greater depth and knowledge about acoustic performance parameters and I add this post only as an additional aspect to the thread.
The Doctor
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Author: Dee
Date: 2002-09-17 16:22
Mark M wrote:
>
> Well, I might be missing something here. I know all
> about the effects of temp, altitude, humidity etc on air
> density since I'm in the aerospace business. I have some
> really basic questions though. 1) If I'm 50c flat when I first
> start out blowing a horn, and, I come into tune after 5 min. of
> playing, and the air out of my lungs have not changed in temp,
> altitude, humidity, why does the horn come into tune?
I believe it is because the temperature of the surface of the horn and the air going through it have reached equilibrium. i.e. When you first start to play, the horn is over 20 degrees colder than your breath. It cools the air as the air goes through it. Once the horn is warmed up, the air temperature inside the horn doesn't change.
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