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A new way to see a saxophone

jbtsax

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Notice how the wavelength for the note Ab concert behaves as if it begins at the apex of the "imaginary" missing cone. What a cool instrument we play. The "missing cone" is also longer than the neck itself.

 

jbtsax

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It is fascinating how the saxophone's notes wavelengths can behave as if they started at the point of the "imaginary missing cone". It has to do with the fact that the reed when it is "beating" (opening and closing the end of the mouthpiece) is not open 50% of the time and closed 50% of the time as it is on the clarinet. On a saxophone the open part of the reed's oscillation is longer than the closed portion. In fact the closed portion is equal to the time it would take the sound wave to travel from the end of the neck to the apex of the missing cone and back. Since the wavelength is a function of the speed of sound and time, this is how the wavelength of notes can seem to reach the tip of the missing cone and return.
 

Sue

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I tried to fathom this then asked by husband to explain it. I still think a missing cone is something to do with ice cream. Walks away blushing ...
 

Colin the Bear

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Your husband is By? Or have you caught a cold? Missing cone? Frequencies and oscillations? I'm having enough trouble getting the notes in the right order.
 

jbtsax

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Your husband is By? Or have you caught a cold? Missing cone? Frequencies and oscillations? I'm having enough trouble getting the notes in the right order.

I sense your "frustum" - ration with this topic. If only our saxophones didn't need to be "truncated" in order blow into them, all of this would be much simpler.
 

kevgermany

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I tried to fathom this then asked by husband to explain it. I still think a missing cone is something to do with ice cream. Walks away blushing ...

A sax behaves musically as if it's a cone. A very long cone. However such a long cone is impractical, and too narrow to get any useful amount of air (vibrations really) into it. Some clever person a few years back discovered that if he cut the sharp end off the cone and replaced it with a mouthpiece from a clarinet, it would play in tune if the air volume inside the mouthpiece was the same as the air volume in the cut off cone. That was of course Antoine-Joseph "Adolphe" Sax...
 

jbtsax

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It is important to remember that Antoine Joseph was also very expert at designing and making conical brass instruments, and he was also very familiar with the "ophicleide" which was a large conical bore keyed bugle. Some speculate that he first experimented with putting a large bass clarinet type mouthpiece on an ophicleide and went from there. The first prototype saxophones were very large and then he continued making them progressively smaller and more refined.
 

aquatic

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It all revolves around the Bernoulli principle, air pressure, creation of a standing wave, and altering the standing wave length. The Bernoulli principle explained by blowing between two sheets of paper is a fun way to show children how the principles work. If anyone here really wants to know the physics behind how saxophones work, I studied music at university and would be happy to copy my notes on this (yawn) amazingly fascinating stuff that really had me riveted to my seat. Actually it was fun to study. So if you want it, let me know. Not at home for a couple of weeks, but all my books are at hand when I get there.
 

jbtsax

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That would be fantastic. I am always looking for new resources. You are welcome to join the new Saxophone Acoustics Facebook site and join in the discussions.



Edit: it should read yahoo site (see later post), but the link should still work. Kev
 
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aquatic

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No problem, as soon as I get home I will scan some of the notes I have that are relevant to this post in particular, zip em up, upload them and post a link here. I will post details of some other stuff I have to see if it takes anyone's fancy.
 

aldevis

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That would be fantastic. I am always looking for new resources. You are welcome to join the new Saxophone Acoustics Facebook site and join in the discussions.

Facebook has on me the same effect Kryptonite has on Superman.
I prefer your lovely posts here.

BTW, how would a Kryptonite™ tenor mouthpiece sound, compared with a standard Molybdenum?
 

Jamesmac

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Facebook has on me the same effect Kryptonite has on Superman.
I prefer your lovely posts here.

BTW, how would a Kryptonite™ tenor mouthpiece sound, compared with a standard Molybdenum?

Would have the K factor instead of the X factor. Simon says.
 

aquatic

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Please excuse my tardiness in being so late with the promised info. Lost my old mum not long after I posted here last.
Anyway I scanned the main points of standing wave creation and created a pdf file. I have no idea how to upload it here so I just uploaded it to a share site.
http://rapidshare.com/share/F88A0B14372858F2838D4C9A1CF5E727
It is just over 8Mb in size and 9 pages long. Just the basics, and it assumes you know a little about waves and air pressure, school stuff.
 

kevgermany

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Really sorry to hear about your Mum. Hope you're getting on OK.

THanks for the file! Can't get the link to work, though.
 

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