I'm no expert, but here's my guess.

High notes are high because there's a lot of vibration (the reed).


The warmer, the more the molecules will vibrate (the colder, the less).

One plus one makes two:

The molecules in the sax will vibrate less, thus producing a lower sound.
I think (therefore I might be)

 

I think it may have something to do with metal expansion in change in temperatures...

How it works, though, I can't say.

 

yes, it is the metal expansion /contraction.

The horn actually gets slightly smaller when it is cold out and slightly larger when it is hot.

just like a baritone plays lower notes than an alto, when the horn gets hot the metal expands by a small amount and the note produced is lower (aka flat)

The opposite is true for when it gets cold (sharp)

this is why it is so hard to get a horn section in tune if the temp is very hot or very cold. I doubt that the horns all expand /contract at the same rate.
The worst atmosphere to play in is one where the temp is changing. if your practice room or performance space is cold when you start and someone turns the heat up, the horns will keep expanding more and more the hotter it gets. Also heat rises, so if you are playing for a while then take a break and put your horn on its stand (on the floor) where it is colder it will start to contract again. All this makes it very difficult to keep the horn in tune.

Best to try and play in the nice A/C 8)

 

yes, it is the metal expansion /contraction.

The horn actually gets slightly smaller when it is cold out and slightly larger when it is hot.

just like a baritone plays lower notes than an alto, when the horn gets hot the metal expands by a small amount and the note produced is lower (aka flat)

The opposite is true for when it gets cold (sharp)

this is why it is so hard to get a horn section in tune if the temp is very hot or very cold. I doubt that the horns all expand /contract at the same rate.
The worst atmosphere to play in is one where the temp is changing. if your practice room or performance space is cold when you start and someone turns the heat up, the horns will keep expanding more and more the hotter it gets. Also heat rises, so if you are playing for a while then take a break and put your horn on its stand (on the floor) where it is colder it will start to contract again. All this makes it very difficult to keep the horn in tune.

Best to try and play in the nice A/C 8)

That means to have to go to the technician for some minor adjustments everytime the weather changes.

 

sorry, that doesn't make sense

If it's cold, it's shorter, thus sharper, wouldn't it?

And you know, you play flat when it's cold.

I rest my "vibration" case

 

No, cold=>flatter, warm=>sharper
Its the temperature of the air column that matters.
The frequency (pitch) of an air wave can be approximated by the velocity of air divided by the wavelength of the vibration. The wavelength is controlled by the fingering (in a general sense) but the speed of air is determined by the temperature of the air column (speed is greater at higher temperatures); so... with the same fingerings a cold air column would sound flatter than a warm air column

 

This is probably true

 

Jan, you are correct, I had it backwards and that throws my whole argument off. I found a couple of things online that support your idea.

"Sounds can be heard clearer on a cold night-
The speed at which sound travels through a medium depends on the elastic properties and density of that medium.
In general the more dense the medium, the greater the speed
As the temperature increases so does the speed
The fact that the speed of sound in a gas increases with temperature sometimes causes refraction
On a warm day the air near the ground is warmer than the air higher up and sounds travel faster near the ground
This causes it to be refracted upwards
At night the air near the ground is cooler and the sound is refracted down and appears to travel better over the ground."


"Warming up wind instruments. As a saxophone warms up, you need to pull the mouthpiece out to keep it in tune. Thing is, this doesn't seem right to me. As a sax gets warmer, I should think it would expand, making the tube bigger and longer, forcing a player to compensate by pushing the mouthpiece in to shorten it up.

Metals expand by about .001% to .002% per °C. And in any case, the metal itself doesn't warm up much. So the change in the dimensions of the instrument are negligible.

Two things happen when the instrument warms up. First, the air inside becomes warmer. The speed of sound in air is proportional to the square root of the absolute temperature. Normal temperatures in a sax are roughly 300 K, so this effect is worth about 0.17% per °C (K is for Kelvin, the units for absolute temperature. A temp difference of 1°C and 1K are the same, so you convert to K simply by adding 273 K to the temp in °C.)

The other important thing is that the air in the instrument becomes humid: your breath is nearly saturated at 37°C and when it cools in the instrument, water condenses on the metal providing a water reservoir to keep the air nearly saturated in the instrument. The speed of sound is is inversely proportional to the square root of the average molecular mass of the air. Water molecules are lighter than nitrogen or oxygen, so humid air is less dense than dry air, all else equal. (Yes, I know that non-scientists talk about humid air being 'heavy', but I think that by this they mean that one sweats less effectively in humid air.) From normal values of humidity to saturated can increase the speed of sound by 0.1 to 0.2%.

So it's easy to have 1% or even 2% or more increase in speed of sound, and therefore in playing frequency. A semitone is only 6%, so this is a lot."

 

I don't think that because of the expansion or the contraction of metal that made the different, since changing a couple degree wouldn't make the metal of the sax expand/contract... I think tt's more from the air column that affect the sound.

 

A quote from Gordon at another post:

Very high thermal expansion seems to me to be incongruous with extreme dimensional accuracy when it is moulded, so I suspect its thermal expansion is actually very low. Anyway, typical thermal expansion of metal is not a problem on saxophones. It is the expansion of the air inside that changes the pitch.

 

I'm pretty sure it is because the AIR moves slower when it is colder. No matter what you use to create a sound -- it is the AIR that carry the sound waves.

 

http://hyperphysics.phy-astr.gsu.edu/hbase/sound/souspe.html

Sw3119 was correct with his second post. The flattening occurs because the sound waves travel more slowly at lower temperatures.

 

Found this old thread. This makes sense. I could never understand how expansion or contraction could make such big impact. Thanks! I feel wiser now…

I tried to think a little further on this. My first question was whether the internal relationships between the notes/keyholes are the same if the density changes, and I guess you could say that they are, since a tube half the length will sound a perfect octave above no matter what the density or speed of sound is. And the notes between will line up nicely as they should.

But what happens if I try to adjust back to a normal pitch?
Let's say that the average temperature inside my tenor saxophone on a nice early summers day in Paris is 25 degrees C. According to Doug R's table this should give a speed of 346.65 m, and the wavelength of my middle Bb on the horn (208.60Hz in 442Hz tuning) should be about:

(346.65 / 208.6) / 4 = 41.54 cm, which I suspect is about half of the length of my tenor plus the mouthpiece. The wave length of my low Bb should be 83.09 cm. Is my math correct here?

In my bad isolated rehearsal space on a cold winters day, let's say the temperature inside my sax in an extreme example goes down to 15 degrees on average. My middle Bb according to the table with the rest being equal should sound like (340.55 / 0.4154) / 4 = 204.95 Hz, which equals 434.28 Hz tuning. I push my mouthpiece in about 0.73 cm to compensate on the middle Bb, which gets me back to (340.55 /( 0.4154 - 0.0073)) / 4 = 208.6 Hz (442 Hz tuning).

But then my low Bb sounds like (340.55 /( 0.8309 - 0.0073)) / 4 = 103.37 Hz, which equals 438 Hz tuning!
I don't know what happens with the octave key pressed in, but I suspect it could go higher than 442 Hz.

So this could be a bit ugly with a large ensemble trying to get back to the normal tuning. But I may be way off here, I was a bit quick. But even if my math is a bit wrong and there's a lot of factors, the conclution might still be the same, that you cannot just adjust back into 442 Hz with the mouthpiece when it's cold.

 

OK - So why? - Just as the saxes are going flat - the exact opposite happens with the guitars?

 

Metal strings contract when it's cold. Shorter strings, higher pitch.

 

Well, its pretty simple really.

When you place a water bottle in the freezer what happens? The bottle itself deforms because of the expanding water.

This means that when we play saxophone in the cold, the saxophone itself expands, resulting in a flatter instrument.

However, I dont really think playing in hotter weather applies. Heat wouldnt really have any effect on an instrument unless its extreme heat.

Anyways, just my two cents.

JJ

 

Well, its pretty simple really.

When you place a water bottle in the freezer what happens? The bottle itself deforms because of the expanding water.

This means that when we play saxophone in the cold, the saxophone itself expands, resulting in a flatter instrument.

However, I dont really think playing in hotter weather applies. Heat wouldnt really have any effect on an instrument unless its extreme heat.

Anyways, just my two cents.

JJ

Water is one of the few things that expand in cold. Metal shrinks, but the sound comes from the air column on a sax. THe physics link above illustrates the effect nicely.

And, yes, Fader, this is a problem, not just with guitar vs. saxes, but also orchestra strings vs. winds. As the temperature changes, the strings and winds change pitch in the opposite direction.

 

You all seem to forget that the warm air of our breath also warms up a metal instrument. When I have to play in a cool room or concert hall, church, I finger low Bb and keep pumping warm air until I get the level of pitch I want, usually about 442, tops 443. And we retune after every piece. Don't forget when the metal expands, it expands in both directions. That means that the thickness of the inside side of the metal also expands, ergo, the instrument plays higher, its smaller, has less room. Does that make sense?

 

I'm not sure that the thickness of the tube affects the pitch. I think the length of the tube affects the pitch, while the thinkness or shape of the tube affects the timbre.

Interesting reading:
http://cnx.org/content/m12589/latest/#s1

 

I am pretty sure that

cold air is denser than hot air

cold water is denser than hot water

ice is less dense than water

glass is a non newtonian liquid and over centuries will sag to the lower part of a window

Water does not expand as it gets colder .... it changes density (expands) when it changes state and turns to ice.

How long does it take to tune a guitar .... no one knows for sure as it hasn't been done yet

 

I'm sure you could read up on the science of this phenomenon and find out the truth of the matter. Maybe when I have the time and am feeling less lazy I'll do it. In the meantime I'll contribute my speculation on the matter:

I doubt very much that expansion or contraction of the metal has any bearing whatsoever on the horn going sharp or flat. I can't imagine the amount of metal distortion in a sax would be enough to have an effect (I could be wrong!!). So I agree with those who say it's the air column. Cold, dense air vs hot, less dense air. That has to have a significant effect.

Let me add I hate playing in extreme temps. Cold is the worst. Too hot is not much better. Give me a nice warm (not too hot, except for the female patrons) bar anytime!

 

Shape of the 'tube', yes, thickness, no. The physics link explains the phenomenon. It's the temperature of the air, not the horn itself. When you blow into your horn, the air inside is warmed. That's what causes the pitch change.

 

Ok here's the deal.

Frequency = speed of sound/wavelength

Once you tune your instrument by setting the mouthpiece on the cork, the wavelength (length to the open tonehole and back inside your instrument) remains constant. Therefore the Frequency (pitch) is inversely proportional to the speed of sound which is determined by the temperature of the air inside your instrument.

For example A = 440 vps (hz) has a wavelength of .784 meters at a speed of sound of 345 m/s (meters per second)

The formula is: Frequency(F) = speed of sound(C) / wavelength(L) or F = C / L

The speed of sound is increases approximately 1 meter per second for each 3 degrees F increase in temperature. The reverse is true as the temperature drops.

If the instrument is tuned to 440 vps at 68 deg F (speed of sound = 343 m/s) and the temperature goes up to 77 deg F (speed of sound = 346 m/s) here is the effect:

F = C/L F= 346/.779 F = 444.2

Is that a big change? Each cent between A = 440 and Bb = 466.16 represents .26 vps or each vps = 3.84 cents. Therefore a rise of 4.2 hz would increase the pitch by 16 cents.

The effect of the expansion and contraction of the instruments is negligible for band instruments. There is however, an effect upon orchestra strings. When the heat in the auditorium stage rises the winds go sharp, the strings go flat, the tuned percussion stay in tune, and the conductor goes crazy.

Another dilemma is that on cold wind instruments the player's warm breath warms up the top of the air column sooner than the bottom making the instrument out of tune with itself. This is especially true of the longer woodwinds such as bass clarinets, bari saxes, and bassoons.

 

Ok here's the deal.

Frequency = speed of sound/wavelength

Once you tune your instrument by setting the mouthpiece on the cork, the wavelength (length to the open tonehole and back inside your instrument) remains constant. Therefore the Frequency (pitch) is inversely proportional to the speed of sound which is determined by the temperature of the air inside your instrument.

For example A = 440 vps (hz) has a wavelength of .784 meters at a speed of sound of 345 m/s (meters per second)

The formula is: Frequency(F) = speed of sound(C) / wavelength(L) or F = C / L

The speed of sound is increases approximately 1 meter per second for each 3 degrees F increase in temperature. The reverse is true as the temperature drops.

If the instrument is tuned to 440 vps at 68 deg F (speed of sound = 343 m/s) and the temperature goes up to 77 deg F (speed of sound = 346 m/s) here is the effect:

F = C/L F= 346/.779 F = 444.2

Is that a big change? Each cent between A = 440 and Bb = 466.16 represents .26 vps or each vps = 3.84 cents. Therefore a rise of 4.2 hz would increase the pitch by 16 cents.

The effect of the expansion and contraction of the instruments is negligible for band instruments. There is however, an effect upon orchestra strings. When the heat in the auditorium stage rises the winds go sharp, the strings go flat, the tuned percussion stay in tune, and the conductor goes crazy.

Another dilemma is that on cold wind instruments the player's warm breath warms up the top of the air column sooner than the bottom making the instrument out of tune with itself. This is especially true of the longer woodwinds such as bass clarinets, bari saxes, and bassoons.

SOMEONE IS WRONG ON THE INTERNET.

(but it's NOT jbtsax)

 

Here's my guess.

I'm not flat because it's cold outside. I've mearly failed to push the mouthpiece in far enough (but that never happens).

My palm keys are flat and my bell keys are sharp relative to the center of the horn.

My unscientific explanation is that the tone holes were positioned to be relatively in tune with each other at a certain temp. At cold temperatures, the relationship between the tone holes and the length of the horn has changed. The horn has slightly shortened, so, relative to the length of the horn, the top holes are too low, the bottom holes are too close. As the horn warms up from playing the top warms up first, so the palm keys come into tune before the bell keys, because the bottom of the horn is still too short while the top of the horn is the correct length. After awhile, the rest of the horn warms up to playing temp, causing bottom of the instrument to expand and the pitch to drop on that end.

This is why crescents work on horns with bad intonation. It's all about relationships and distance from the mouthpiece.

That said, some of my relations I would prefer to keep distant. Particularly those involving the in-laws.

 

sigh . . .

 

At my job, I work with a bunch of subject matter experts. Here's the usual answers to any observed phenomenon:

* Engineer - the machine causes it.

* Physicist - changes in conditions (air, pressure, temperature, etc.) caused it.

* Accountant - it was due to trends caused by budget restraints.

* Doctor - the user must have been ill.

* Industrial Hygienist - changes in the user affected by the machine and physical conditions caused it.

Since I'm the industrial hygienist, I say the cold or hot weather and cold or hot horn affects the player who then plays sharper or flatter. But that's just me.

 

This is getting hilarious! :lol:

 

* Plumber - the effect is cause by bad pipes.

* Electrician - not enough wiring in the saxophone.

* Welder - it's caused by improper soldering

* Conspiracy Buff - Adolfo Sax was an elite member of the Illuminati. He designed the cold/flat-hot/sharp flaw into saxophones as part of a larger secret plan to obtain world control.

* MartinMods - it happens because the mouthpiece volume is not matched to the sax. And only I understand why.

* Jbtsax - it's not a problem because Benade said it's not.

* Comedian - this effect is the result of a big joke.

 

Why is it, when the answer to an interesting question is posted on an internet forum, there are still people offering further (wrong) answers? Not just here, I see it other places too. Is it because those people don`t accept the answer? Is it because they don`t even bother to read the replies? Is it because they can`t resist furthering non-truths? What?

jbtsax explained this. The effect is also demonstrated when you breathe helium. Since that gas is less dense than air, the sound travels faster/the molecules vibrate more so our voice is pitched higher.

 

:banghead:

 

You've touched on something important here. One of the more difficult things to do is to actually "hear" what the other person is saying in a conversation. Listening to someone else is not the same as really hearing them. A friend of mine calls this "listening deeply". It is far easier to gloss over what you think you heard because you are more concerned with making your point. It is next to impossible for someone whose mind is closed to thoughts and ideas that may be different from their own to "listen deeply" and really hear what the other person is trying to communicate.

A good example can be heard on any daytime talk show where two people with different ideologies are invited to speak. Neither one listens to the other's point of view, they simply keep hammering their prepared talking points even while the other person is talking. This is not a discussion or a conversation. Posting on a discussion forum is just like having a conversation in person. Careful, thoughtful listening (reading) to really hear the other person's message before posting a response would make for a much more meaningful (and intelligent) conversation.

 

You've touched on something important here. One of the more difficult things to do is to actually "hear" what the other person is saying in a conversation. Listening to someone else is not the same as really hearing them. A friend of mine calls this "listening deeply". It is far easier to gloss over what you think you heard because you are more concerned with making your point. It is next to impossible for someone whose mind is closed to thoughts and ideas that may be different from their own to "listen deeply" and really hear what the other person is trying to communicate.

One of the new problems today is information overload. Folks have opinions and statements of "fact" pushed at them from every angle. So in response, people are filtering facts more by there own personal beliefs and assumptions. In aggregate, this may actually be beneficial to combat all the false information they are being fed. But it's also a problem because people can no longer discern authoritative fact from false information. So as wrong as this attitude is, it's not the folks are not listening to you, it's really that they are dismissing you as not worth hearing.

So in the end, people now tend to hold on to their own preconceptions more even in the face of hard information to the contrary. I have two teenagers and they basically have learned not to believe anything they read, hear or have been taught. On the up side, they are far far less gullible than my generation was at that age. But on the other side, the whole idea of "truth" has been diluted to the point that it is just as gray as false information and unqualified opinions.

And this conversation is a prime example. No matter what an expert says and no matter how simple the science it, someone else could probably find three experts with equal or greater credentials that will say something else. And on on an internet forum, everyone gets to equally be an expert. So there you have it. Human nature at work. :bluewink:

PS: I think that here on SOTW, we are a lot better at qualifying our advice and answers when we are talking about saxophone playing. Most members, will start their advice by stating their own limitations or defer to other more accomplished players that might have better information. But on matters of acoustics and other subjects away from actually playing a sax, this forum just becomes a free for all just like any other forum out there.

 

I heard that.