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Does the position of the bell brace have an effect on accoustics / resonance of the tone

9K views 51 replies 16 participants last post by  kymarto 
#1 ·
I know there are several discussions about the lacquer etc on the surface of the Saxophone, also how the thickness of the metal has an impact etc.

But, did anyone ever consider the placement of the bell brace in terms of accoustic resonance?
Or is this simply an engineer decision finding the simplest spot to put it in for manufacturing and repair?
 
#3 ·
Oh my, that was many pages to read - very interesting and I will need to read it again.

I think the theories of many instruments is sort of straight forward.
But then when we experience the sound of two instruments of the same type being very different - that's when other things come into play.

I play many different electric guitars and although the theories say that one or the other wooden board should not make any difference, it does.
Subtle resonance in the board makes the mics vibrate differently, how the neck attach to the board will influence the vibrations and create that twang that we like to hear.

Why wouldn't the position of the bellbrace and how it was manufactured/soldered have an impact on the sound of the saxophone.
In many other instruments the position and characteristics of joints are the most important things to care about.
Here we have the saxophone with a very firm and not very elegant joint and yet noone seems to have studied it more carefully from a sound perspective.

I have resoldered some of these and just thought it was important to get the toneholes to match the pads. I myself did not either consider the position as maybe I should have. (Now that last sentence is worrying even to me!)
Maybe I should quickly get out of this discussion before I become obsessed with documenting the locations and qualities of every bellbrace ever placed on a saxophone.

Anyone wants to pick up on this feel free - until you are placed under 24h surveillance and a nurse asks: How are We doing today?
 
#5 ·
That is why I was referring to an electric guitar without any accoustic box.
It still creates different sounds from the strings not being fixed in space since the so called stiff board has a life of itself.

I would imagine the same with the metal around the air column, i.e the air column is pushed around by the resonating metal.
The resonance of the upper stack is transferred to the bell through the bellbrace...or the resonance of the bell is prohibited by the bellbrace.

Have you not felt the vibration of a bari sax.
Put a bass clarinet to your leg when playing and you will feel the vibrations.
 
#9 ·
Why ofcourse it is the aircolumn that pushes around the metal and not the metal that initiates the frequency of the aircolumn.

But are you saying that the metal is not affected at all by the aircolumn and different wave lengths over tones etc. There is no feedback involved where the horn resonates energy back to a changing air column with slight delays thereby affecting the sound.

So in essence I will have to accept the fact that the horn itself is as solid as a rock no matter what the thickness of the metal is, no matter where my hands are placed on the outside of the sax, no matter where joints are placed holding it together, no matter how open pads are resonating and projecting this back into the horn through the mechanics etc.

OK.
 
#12 ·
Surely many aspects of the sax- material, lacquered or plated, original lacquer or relaqu'd, thickness of material, buffed for sizzle or left alone for darkness, type and material of reso's if any, grip of the player, material of the mouthpiece, temperature of the air, humidity of the air, et al- have an effect upon the sound produced. I don't think anyone seriously disputes that. What is disputed is whether the effect is significant or even detectable.

If you blow a puff of air across the street with your mouth the neighbors car is affected at some level; but not so's you can tell.

The history of sax manufacture is replete with different bell brace designs all purporting to have an effect on resonance. Steve Goodson, never one to shy away from design features with large but iffily documented purported effects, specifically cites the location of the brace (lower down) on his bells as having a return in increased resonance.

Along with precious stone key touches and P-ligging there's almost certainly some effect at some level- but the level of that effect? No documented scientific studies from me either- naught but pure opinion- but I'm not sold that it's anything but well under the noise level.

Try any given horn- regardless of features. If you like it, you like it. It sounds how it sounds. Instrument design and building beyond the basics is still art, not science. The "devil in the details" features from finish on down are simply not reliable as an indicator as to whether the horn will sound as you want it to.
 
#51 ·
Surely many aspects of the sax- material, lacquered or plated, original lacquer or relaqu'd, thickness of material, buffed for sizzle or left alone for darkness, type and material of reso's if any, grip of the player, material of the mouthpiece, temperature of the air, humidity of the air, et al- have an effect upon the sound produced. I don't think anyone seriously disputes that. What is disputed is whether the effect is significant or even detectable.
A lot of things have been stated in this discussion. I think this quote makes good sense, but as with most things, there are many sides to it. The acoustically main factors are the vibrating air column, as already said, but wall inertia is not entirely without effect. A metal wall does vibrate and takes energy from the vibrating air and probably gives back some. Whether or not a bell brace is important here is a subtle matter. In cases it could be, as stated by others. I changed a bell brace in my baritone with good effect to the general stabiltity of the instrument (which is not without importance to the correct closing of the lower keys!) but with no effect to sound whatsoever, as far as I remember.

Yet, there are interesting experiments by trumpet-makers (Harrelson among others) using different wall thicknesses and they do report differences in response. I did some experiments in the same bari with the crook fortified with lead rings, and also noted a difference in response. Jim Schmidt once used brass rings around the necks of his instruments to the same effect. I once heard about some experiments with a neck made inert with a rubber lining on the outside. In the same way, Ernest Ferron states that the strips of brass which carry the pillars make a difference too. Might be, I never tried to verify, as this is nearly impossible...

The acoustician Nederveen once said to me that although theoretically it is the air column only and nothing could be proved scientifically about the influence of wall material, yet the trained musicians' ear might prove to be the more suble of measuring instruments. You see, a fine scientist is always willing to doubt.

M.
 
#13 ·
Ok - now I am going out on a limb and give some OPINIONS based upon my experiences, both as a player and as a repair tech.

The theory of the air column is fact. No arguments there, however it is my OPINION that once the column of air resonates, it transfers the resonance to the metal body tube (and bell, and neck). The resonating tube, then re-affects the column of air in the tube and changes the character of the sound. (NOTICE I DID NOT SAY "TONE")

I can give one clear example (in addition the the many subtle ones that would take to long to explain here).

Years ago, my 1969 Buffet SuperDynaction Low A Baritone was my main horn while studying at SUNY Fredonia. The bell to body brace is the same design (and size) for the Alto, Tenor, and Baritone. This resulted in a brace that is too small for the large bell of this Low A saxophone, and thus it broke.

I had it soft soldered when I was in college. It broke again. Well, after a few times of it breaking again over the next few years, I had enough, and as I was apprenticing at a repair shop, I decided to fix it right. I took off all the parts of the brace, silver soldered them all together, then put them back on the horn as a one piece brace.

Now, here is where it gets interesting. Over time, the weight of the bell bent it slightly forward, so in order for the brace to be attached needed to be bent against the natural spring of the situation at hand. This is how it had been since the last repair, which means the brass of the saxophone had constant strain at that point.

When fixing this problem now the correct way, I straightened the bell so the brace fit between the bell and body with very LITTLE pressure holding it in place - thus no strain or pressure on the brass.

When the "fix" was finished and the horn was re-assembled - the resulting resonance was astounding. Again, not change in sound, but change in resonance. The old brace attached under tension, hampered the transfer of free resonance in the body tube from the air column.

I will also add that later in life I had this horn silverplated. Again, sound did not change, resonance did however.

It is MY OPINION that things that impact the secondary resonance of the body (primary being the air column) , are perceived by the player as a change in sound - but in reality are a change in resonance.

OK people, I am ready for you to hang me at the old oak tree for these opinions now. I will bring my own rope and black hood.

Charlie
 
#15 ·
Ok - now I am going out on a limb and give some OPINIONS based upon my experiences, both as a player and as a repair tech.

The theory of the air column is fact. No arguments there, however it is my OPINION that once the column of air resonates, it transfers the resonance to the metal body tube (and bell, and neck). The resonating tube, then re-affects the column of air in the tube and changes the character of the sound. (NOTICE I DID NOT SAY "TONE")

I can give one clear example (in addition the the many subtle ones that would take to long to explain here)...
...When fixing this problem now the correct way, I straightened the bell so the brace fit between the bell and body with very LITTLE pressure holding it in place - thus no strain or pressure on the brass.

When the "fix" was finished and the horn was re-assembled - the resulting resonance was astounding. Again, not change in sound, but change in resonance. The old brace attached under tension, hampered the transfer of free resonance in the body tube from the air column.

...It is MY OPINION that things that impact the secondary resonance of the body (primary being the air column) , are perceived by the player as a change in sound - but in reality are a change in resonance.

OK people, I am ready for you to hang me at the old oak tree for these opinions now. I will bring my own rope and black hood.

Charlie
Hey, that was a fresh breath of air into this discussion.:bluewink:
you are confirming what I tried to say before.

So there could be improvements made to the resonance of a horn if the bellbrace was altered as you say so there is no strain attached to it allowing the metal to resonate more freely.

It would be interesting to find out if there is any experience out there for which brands/models the bellbrace is in its sweet spot.
 
#20 ·
Related, perhaps -- here's a little experiment that I did about a year ago. I found significant vibration of the metal at various points on the horn, depending upon the sounding pitch. Most surprisingly to me, the bell vibrated most strongly when playing high Bb.

Also, Selmer Serie II and III baritones have a small screw to adjust the resonance of the bell. It makes a difference, in my experience.

 
#47 ·
Related, perhaps -- here's a little experiment that I did about a year ago. I found significant vibration of the metal at various points on the horn, depending upon the sounding pitch. Most surprisingly to me, the bell vibrated most strongly when playing high Bb.
I've tried this with various ordinary saxophones and got no vibration when I place a metal object on the body. The strapping and holes and so on make a difference to how well the body vibrates. How well your tube will vibrate at different points depends on where the nodes and antinodes are at different pitches. These will be different on a full instrument.
 
#21 ·
I'm not sure what is meant by 'resonance' in the sense that you're using it here.

Also, if you bend the bell back more toward the rest of the horn, aren't you modifying, slightly, the geometry of the horn?
 
#23 ·
Resonance the way I am using it is the intensity of vibrations caused by the sound in the air column. I also find that the greater the vibrations, the bigger the sound - again just an OPINION.

As far as bending the bell back towards the rest of the horn - the bottom bow is where this bending is occurring, and it is a situation where a small bend has a great distance because the noted problem is much further away. I.E. - a 0.25 degree angle at the source does not have much distance in the ray (is that the right term? - pulling from jr high math classes here) - however a couple feet away the distance of the ray (again excuse me if I am using the wrong term) could be a half inch or so.

That is enough to cause the amount of tension in the brace (if not fixed properly) that can cause the problem I am talking about.

Also - think of the repair as putting the bell back to where is was meant to be as opposed to changing the inner bore dimension.
 
#22 ·
Clearly, moving the bell would have an effect upon the geometry- though even a pretty severe movement of say a quarter inch at the point of the bell brace contact would probably not prove acoustically detectible, especially in a baritone.

I took Mr. Roseen's comments to address the <perceived> vibration in the bell, not the sound coming out of the horn though.

There would surely be a difference in that aspect as a result of relieving the effective preload induced by a stressed bell stay attachment. I believe Drake Sax Prof's observations would seem to support this notion.
 
#29 ·
AFAIK the vibration modes of the bodies of wind instruments has been studied quantitatively, including the way that vibration couples with the vibration of the air column. Not to mention the amplitude of vibration measured. And the conclusion is that for woodwinds, the vibration of the body of the instrument sends out sound waves to the listeners ear that are sufficiently minute in volume that although they can be measured by test equipment, they are not discernible to the human ear. And double blind testing confirms this.

By comparison, the sound produced by the vibration of a bell of a brass instrument, particularly French horn, begins to be discernible, and of course the bell is involved for every note, which is definitely not the case for woodwinds.

However some woodwind bodies vibrate a little more than others, and I am sure that when I experience that, my easily deceived senses and brain interpret that tactile pleasure as improved sound. The audience, of course, would not experience that.
 
#30 ·
And the conclusion is that for woodwinds, the vibration of the body of the instrument sends out sound waves to the listeners ear that are sufficiently minute in volume that although they can be measured by test equipment, they are not discernible to the human ear. And double blind testing confirms this.
We are all talking about our perception vs listener perception (or mechanical measurement)

My question is to the player's perception. How often do we see a guy play something and say - "do you hear that?" when in truth we the listener, heard nothing.

I was taught that the way we hear ourselves is based upon the fact that sound travels faster through solids than air. Your jaw bone is the link between your mouthpiece and your eardrum.

So "we the player" will notice things that "they, the listener" could care less about. We then try to impose what we experience onto the listener, they just think we are crazy and obsessive.

In truth, we are! :)

Anything not humanly connected with the saxophone during performance, in my opinion, lacks the technology to perceive the sound as the performer does. Very similarly as a photo will never be EXACTLY as good as the real image.

The REAL talented guys are the ones "in touch" with this aspect at some level, and can convey, or bring notice to their own perceptions.
 
#33 ·
It's certainly more of a change than removing the lacquer:)
 
#34 ·
Think so?

I believe neither would be audible.

The change in volume or bow cross section caused by a one (or two) degree bend would be very, very, small- less than the change effected by sticking a one inch square piece of tape on the interior surface. Even that small effect would largely be erased when the bell was flexed to come up against the stay.

The removal of lacquer- and I'm in the "no audible effect" from finish camp- might have some minute effect on the feel of vibration transmitted to the fingertips on some notes.

So might the relief of tension from the bell.

I'm speculating that between the two you'd get more effect at the fingertip sensation level from the tension relief than from the delaquering, and that neither would be detectible to any listener. Might be felt to be different in a double blind- but surely not with anything approaching a 100% positive ID even for experienced players.

Absent a study- and I sure have none to cite- I figure "speculation" is about all we have.
 
#35 ·
Absent a study- and I sure have none to cite- I figure "speculation" is about all we have.
Speculate on then. At least one horn tech that I consider credible, Randy Jones, makes it part of a rebuild to remove the tension from the bell brace (remove the brace, reset the bow, reattach the brace in the tension-free position).
 
#36 ·
A few quick comments. The material and design does very definitely affect the sound of an electric guitar. When a string vibrates, energy is lost at the nut and bridge, which are displacement nodes of the string. The mechanical energy of the string is transferred to the body, and how that happens affects the behavior of the string. In fact this is exactly why an electric guitar has such great sustain as compared to an acoustic guitar; in the former, there is no need to transfer energy in order to create sound, whereas in the latter if you don't transfer energy, you can't drive the acoustic resonator.

There is evidence that the only part of a wind instrument in which vibrations might actually have a significant acoustic effect is in an unsupported bell, since it is the only part of the horn that has resonant frequencies low enough to couple at playing frequencies. So yes, the position of the bell brace could make an audible difference, albeit a small one, maximum about 3 dB according to Nederveen.
 
#37 ·
Interesting!
Yes you are right, the sustain of the electric guitar is well designed for wheras for an accoustic guitar or violon for that matter the energy of the string is supposed to move from the string, to the bridge and over to the bottom and top of the soundbox. A violin has a wooden pillar inbetween the top and bottom just in front of the bridge to get the vibration to the bottom.

So a non braced bell is 3dB stronger than braced one. 3dB means twice the power. This is not negligable, is it?
 
#38 ·
1db SPL (sound pressure level) is a ratio that is supposed to be the 'minimal detectable difference' in level. You have to listen quite hard to tell a 1 dB difference between two sounds.

3 dB is 'just noticeable difference', so no, 3 dB isn't that much difference in SPL.

You are correct when you say that 3 dB is double the power (watts). It takes double the power in an amplifier to create a just noticeable difference of 3 dB.
 
#39 ·
3 dB is the maximum postulated difference at certain frequencies. It is most probably much less, based on the fact that a sax has very little bell flare and only on the lowest notes does anything near the full power of the air column vibration reach the bell.

Smith did tests with trombone bells of different thickness and measured a variance of 2dB at certain frequencies at the position of the player's ear. Interesting not one of ten top pro bone players could distinguish between the bells in blind tests.
 
#40 ·
Smith did tests with trombone bells of different thickness and measured a variance of 2dB at certain frequencies at the position of the player's ear. Interesting not one of ten top pro bone players could distinguish between the bells in blind tests.
My question is measuring dB at the outside of the player's ear relevant, because the sound is traveling through the jawbone to a location VERY near the eardrum? If sounds travels faster through solids than gas, is measuring dB outside the body vs through the inside of the body like comparing apples and oranges?
 
#41 ·
First, measuring the sound spectrum in the ambient environment is going to tell us about the sound that is being radiated out from the instrument at that point, a sum of air column and body vibrations. Measuring it at the ear position should tell us what that sum is that is being heard by the player.

Bone conduction is caused by the coupling of body vibrations with the bones in the head, causing them to vibrate, which vibration is transferred to the middle ear to be processed along with the energy entering the ear from the air. Since bone conduction is caused directly by body vibration, any change in sound caused by a difference in body vibration should not be masked by bone conduction, and might even be enhanced by it.

As far as timing differences go, how could that matter? What the player hears in anything but an anechoic chamber is a product of many reflections. They can have a filtering effect, but since that remains constant it can simply be factored out unless the player changes position between trials, seems to me.
 
#42 ·
1st I have to say that I love your posts. There is so much information packed into such a small space that I have to read then re-read them to understand them fully.

I agree that bone conduction enhances our personal sound perception. Just like when we hear a recording of ourselves talking, we are always surprised because we do not hear ourselves in that same way.

I also think those subtle changes in resonance that we talk about happening within the instrument are enhanced through bone conduction. I think this is why we can't always put a finger on what we FEEL is different between saxophones or alterations on a saxophone.

It is this personal connection with a saxophone that some of us embrace more than others, and where I think so many opinions about it's relevance comes from.
 
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