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Are there any possible ways to measure the sound projection without testing an instrument in a hall?


Andreas Preuss
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14 hours ago, Marty Kasprzyk said:

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"Cutting down the higher partials is clearly the design goal of many if not most musical instruments."

Attached are some examples of the high frequency fall-off of other instruments from Arthur H. Benade's paper (2)  

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1.  Eric J. Heller, Princeton University Press, 2013, Chapter 26 'Dissonance and Temperament", section 'Autodissonance' pages 508, 509

2. A.H. Beade, S.N. Kouzoupis, "Spectral envelopes of orchestral instruments", J. Acoust. Soc. Am. 78, S75

 

Attached below are examples of how the addition of a bell to a trumpet (1) and the addition of sound holes to a clarinet (2) have a spectrum "fall off" to reduce the high partials.  The need for a high frequency "fall off" has been known for a long time for musical instruments and it is not unique to the violin.

 

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10 minutes ago, Marty Kasprzyk said:

Attached below are examples of how the addition of a bell to a trumpet (1) and the addition of sound holes to a clarinet (2) have a spectrum "fall off" to reduce the high partials.  The need for a high frequency "fall off" has been known for a long time for musical instruments and it is not unique to the violin.

 

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The lowest graph is the interior impedance. What goes out of the instrument in the open end is the part that does not become reflected. The wavefront in a woodwind instrument or a trumpet is a «flutter» going beck and forth in the conical tube, amplified or sustained by the lips or the beating reed. If the impedence is high in the tube, less enters the room behind he tube. With a cone, less becomes reflected and more enters the room.

Brass instruments have a high frequency effect you may hear in angry elephants, even sportscars or japanese street racers with long pipes as a «brassy» sound. A trumpet eg, playing loud may sound more brassy, perceived as being louder. The brassiness thing is nonlinear, caused by a sharpeing of the wavefront inside the instrument which leads to higher output of higher frequencies. 

Edited by Anders Buen
Some corrections of spelling etc
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6 minutes ago, Marty Kasprzyk said:

The need for a high frequency "fall off" has been known for a long time for musical instruments and it is not unique to the violin.

I think of it as more of a trial-and-error evolution, with the retention of features that people like to hear.

After-the-fact, with electronic measurements and analysis, we are deducing what people prefer to hear... rather than some acoustic design requirement.

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1 hour ago, David Burgess said:

That depends on the unit-mass of the string. A longer string with less mass (or thickness) = same load.

An example of that is a light Zyex E string having a unit-mass of 0.3993g/m and with a tension of 16.8 lb. (74.7newtons) when a 328mm string length is used.  If the string length is increased to 345mm it would have the greater 18.6lb. tension of a Zyex medium E string with its greater unit-mass of 0.4420g/m.

One advantage of a longer lighter string is that it is easier to bow than a shorter heavier string at the same tension.

 

 

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On 11/27/2021 at 5:43 PM, Marty Kasprzyk said:

All of the string overtones are multiples of the basic note. There are no overtones which are not multiples of the basic note.

Two of the higher adjacent overtones can combine to form unpleasant chords to create unpleasant dissonant roughness or raspiness.  I suspect Perlman's Strad has a high amplitude "bridge hill/body hill" as Don just pointed out but that it also has a steep fall off at high frequencies to reduce Dunwald's F band (4200-6400Hz).  His violin acts as a filter which reduce the amplitudes of the upper harmonics. 

I do find Perman's Strad does sound "pure" in the high notes as he says and I like it very much.   For example a C note (1046Hz) on the E string would have the harmonic series 1046 Hz(fundamental or 1st harmonic), 2092(2nd harm.), 3138(3rd harm.).  If his violin has a frequency response curve fall off above at its peak of 3000Hz this C note would have only three strong harmonics and it could not have any unpleasant chords and it would sound "pure" and very noticeable.

So his violin may project better than others because it has a "pure" sound as he claims but it is still important that these first few harmonics have high amplitudes(loud) to give good projection. 

 

 

Maybe pure sound, and not necessarily loud, may be weak-ish fundamentals on the e-string first position and getting support from the bridge/body hill region instead. Maybe also a sharper dropoff at the very highs.

I do not have full control over the bridge body model. But higher damping there can play a role, as well as lower damping of the bridge. In vibration insulation theory, a mass spring system with a dashpot damper (viscous damping) give a stronger filtering above the resonance than does a higher damped system. The response around the resonance will be stronger for the less dqmped system than the more damped one. So a low damped bridge body system may give a clearer bridge/body «formant». 

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3 hours ago, Marty Kasprzyk said:

Attached below are examples of how the addition of a bell to a trumpet (1) and the addition of sound holes to a clarinet (2) have a spectrum "fall off" to reduce the high partials.  The need for a high frequency "fall off" has been known for a long time for musical instruments and it is not unique to the violin.

 

 

Modern trumpets are very loud instruments - anything very loud with a lot of HF content will be unpleasant. Modern clarinets are pretty loud too (and some might say inherently a bit unpleasant).

Quiet instruments (like celestes or bowed psalterys) need all the HF they can get. I would say the violin is inherently not loud, and it relies on high frequency to be heard in most musical contexts.

The average orchestra has 30+ violins and one triangle - no-one struggles to hear the triangle at the back of the hall, however loud the orchestra.

 

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12 minutes ago, martin swan said:

so the thickness of the string doesn't affect the tension at a given length and pitch?

it does, because it affects the linear density.

The linear density is the volume density of the material multiplied by the cross sectional area of the string. Which depends on thickness.

It really depends on what Mr B means by "unit mass". Mass per unit length or per unit volume? You'd normally use the former when talking about strings.

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47 minutes ago, Bodacious Cowboy said:

it does, because it affects the linear density.

The linear density is the volume density of the material multiplied by the cross sectional area of the string. Which depends on thickness.

 

Of course - you only need to use a violin D string as a G to experience this. Or vice versa ...

I was responding to Marty's assertion that baroque string tension was lower. I don't think that's really an established fact since a) the string length was only marginally shorter if at all and b) it depends on the thickness of the string material used. I may be wrong but I think Roger Hargrave argued very persuasively that string tension wasn't necessarily different.

So I don't think we have a basis to speculate about how a baroque conception of projection might have been different. Certainly there were large performance spaces, there were concertos, and there was a musical tradition of voice production.

 

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1 hour ago, martin swan said:

Of course - you only need to use a violin D string as a G to experience this. Or vice versa ...

I was responding to Marty's assertion that baroque string tension was lower. I don't think that's really an established fact since a) the string length was only marginally shorter if at all and b) it depends on the thickness of the string material used. I may be wrong but I think Roger Hargrave argued very persuasively that string tension wasn't necessarily different.

So I don't think we have a basis to speculate about how a baroque conception of projection might have been different. Certainly there were large performance spaces, there were concertos, and there was a musical tradition of voice production.

 

The Hardangerfiddle is kind of baroque. Gut strings, traditionally, and played at a higher pitch. Shorter and lighter strings makes it sound a little weaker than a violin with Dominants mittel. Still the sound is more intense. The bridge is also different with long legs, chelloish kind of. A baroque bridge would also influence the sound spectrum, and I guess the violins were played at lower pitch. Please correct me if i’m wrong. The pitch varied with the region and instruments there, like flutes, or maybe the church organ. 

I am sorry that the baroque violin and fiddles are not studied more in the VSA and in general. I think this limits the insights and makes the violin acoustics subject less interesting than it could have been.

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Changing string lengths and tuning pitches isn't really that hard to do. I think people who have these questions should do their homework and see what the results are. Throw a paperclip wire under the strings a couple of mm short of the nut, retune to pitch (it will be a lot less retuning than you think) and play the thing. What changes, what doesn't? It's not that hard to find out.

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5 hours ago, Anders Buen said:

The Hardangerfiddle is kind of baroque. Gut strings, traditionally, and played at a higher pitch. Shorter and lighter strings makes it sound a little weaker than a violin with Dominants mittel. Still the sound is more intense.

That’s an interesting observation. Overall a weaker sound but more intense. 
Regardless the causes for the intensity where would you think one can see this on graph? Do you have eventually an example?
 

5 hours ago, Anders Buen said:

I am sorry that the baroque violin and fiddles are not studied more in the VSA and in general.

This would certainly be interesting and probably put some serious question marks on the general idea that more string load with high tension strings is not necessarily the best solution to more sound power or projection. 
 

My general (half scientific) observation is that higher string tension automatically needs a flatter string angle. This means that there is somehow a limit to the downforce for a given body structure. Too much downforce has an effect which is usually described as ‘suffocated sound’.

On the other hand I see the major difference to Baroque style setup mainly in the lower tension of the E string. Steel e strings put much more load on the bridge compared to gut strings. This causes a major imbalance on the bridge, which can only partly smoothened out in a modern setup by setting the angle of the e string at a slightly flatter angle than the G string on the other side. 
 

Here is a chart from gamut strings, first figure is the thickness, the bold figure is the tension in kg

e Light 0.52 4.80
e Light+ 0.54 5.20
e Medium 0.56 5.60
e Medium+ 0.58 5.90
e Heavy 0.60 6.40
e Heavy+ 0.62 6.80

 Compared to pirastro gold

E Ball Steel Dünn Envelope 4/4 7.2 we_dunkelgruen-rosa.png sh_goldgelb.pngkugel.png 315111
E Ball Steel Mittel Envelope 4/4 7.7 we_dunkelgruen.png sh_goldgelb.pngkugel.png 315121
E Ball Steel Stark Envelope 4/4 8.5

For comparable thickness (light, medium heavy) steel string tension is for heavy gage 29%, medium gage 34% and light gage  44% more. 


 

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8 hours ago, martin swan said:

Roger Hargrave argued very persuasively that string tension wasn't necessarily so.

I guess that Roger Hargrave meant that the transition from Baroque to modern setup in the early 19th century didn't change the string load to a considerable degree. I absolutely agree to that, because steel E strings were not invented yet. However steel E strings have unarguably a higher tension. (See my answer to Anders Buen) Later, the further development of strings after the early 19th century up to today tried constantly to produce higher string tension first with the introduction of the steel E string, later with other string constructions on the lower strings. 
 

I wrote somewhere else that I see in this connection the trend that workshops started to increase the neck overstand to flatten the string angle. This in return diminishes the down-force on the bridge bringing it back to the load with weaker strings. Long ago at the beginning of the 20th century 5.0 - 5.5mm overstand was a sort of standard on modernized instruments, nowadays we are at 6.0 - 6.5 and I wouldn’t be surprised if this goes even higher in future.

 

8 hours ago, martin swan said:

So I don't think we have a basis to speculate about how a baroque conception of projection might have been different.

IMO the basis for this kind of speculation starts with the use of the baroque bow. 

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9 hours ago, Andreas Preuss said:

That’s an interesting observation. Overall a weaker sound but more intense. 
Regardless the causes for the intensity where would you think one can see this on graph? Do you have eventually an example?

The most compressed version on this is a poster from the 2013 Stockhom Musical Acoustics Conference: https://www.researchgate.net/publication/339587232_Buen_SMAC-242_Poster_A3

The article governing it: https://www.researchgate.net/publication/325392479_THE_ACOUSTICS_OF_THE_HARDANGER_FIDDLE

A more recent presentation, also including some speculations on the string effect, theoretically: https://www.researchgate.net/publication/351283853_Some_aspects_of_the_acoustics_of_the_Hardangerfiddle

There is a later article as well governing this presentation. However, it is very similar to the one from 2013.

If you prefer to hear me talk on a slightly shorter version of the above slides (nothing on the string theory, due to time constraints) i have the presentation from the Baltic Nordic Acoustical Meeting 2021, which was a video conference due to te pandemic: 
https://www.youtube.com/watch?v=YVY7MsN3lZ8&ab_channel=AndersBuen

 

 

Edited by Anders Buen
Trying to add the Youtube movie talk
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2 hours ago, Anders Buen said:

The most compressed version on this is a poster from the 2013 Stockhom Musical Acoustics Conference: https://www.researchgate.net/publication/339587232_Buen_SMAC-242_Poster_A3

The article governing it: https://www.researchgate.net/publication/325392479_THE_ACOUSTICS_OF_THE_HARDANGER_FIDDLE

A more recent presentation, also including some speculations on the string effect, theoretically: https://www.researchgate.net/publication/351283853_Some_aspects_of_the_acoustics_of_the_Hardangerfiddle

There is a later article as well governing this presentation. However, it is very similar to the one from 2013.

If you prefer to hear me talk on a slightly shorter version of the above slides (nothing on the string theory, due to time constraints) i have the presentation from the Baltic Nordic Acoustical Meeting 2021, which was a video conference due to te pandemic: 

 

Thanks so much for posting this.

Before I went to a restaurant dinner with my daughter I made quickly a printout to start reading while waiting for the food.

I am always very much interested in research where there is some reconstruction on one and the same violin is involved. Therefore the neck exchange experiment is really interesting. I still need to digest the details. 

Ona quick read the neck weight seems to influence the bridge hill region. Though I couldn’t see this when I made an ultra heavy Fernambuk neck graft on my new concept violin, now with an entirely different rib structure this might be different. 
 

Just one question. Do you remember what sort were the ‘Chinese strings’ mentioned in the article. I would assume steel strings for G D A E. 

Edited by Andreas Preuss
Clarification of content.
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2 hours ago, Andreas Preuss said:

Just one question. Do you remember what sort were the ‘Chinese strings’ mentioned in the article. I would assume steel strings for G D A E. 

Thanks for being interested! It is a while ago I did these experiments. I do have the strings lying somewhere. I think they are sort of synthetic core strings, not much different from Dominants. They are not of the steel core ones. They are less easy to play, but probably louder. 

The test instrument is of "high grade", thickish as del Gesu but the wood is likely to be stronger. A rather stiff fiddle. 

I have not tested the different Chinese strings in detail. Maybe a thing to look into.

The larger number of violins tested against hardanger fiddles are mainly with mittel Domintants.

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On 11/24/2021 at 10:27 PM, Andreas Preuss said:

That’s what I think, too. But I find it important that the ‘metal in the middle’ is paired with enough breathing from the lower end.

Not so long ago you posted a sound sample of your ‘political incorrect’ built violin played apparently in a hall. What was your motivation to do this? 

It was not in a hall but in my workshop.

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17 hours ago, Andreas Preuss said:

My general (half scientific) observation is that higher string tension automatically needs a flatter string angle. This means that there is somehow a limit to the downforce for a given body structure. Too much downforce has an effect which is usually described as ‘suffocated sound’.

I will agree that there is a downforce limit (best sound and best-playability-wise) for a given body structure.

15 hours ago, Andreas Preuss said:

I wrote somewhere else that I see in this connection the trend that workshops started to increase the neck overstand to flatten the string angle. This in return diminishes the down-force on the bridge bringing it back to the load with weaker strings.

My theory is that higher overstands were mostly to increase the ease of playing in the higher positions. Otherwise, the down-force on the bridge could have been more easily decreased by installing lower unit-mass (mass per unit length) strings.

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1 hour ago, David Burgess said:

Otherwise, the down-force on the bridge could have been more easily decreased by installing lower unit-mass (mass per unit length) strings.

Somehow it is difficult to say what was the main reason for the overstand development, I only see musicians being concerned much more often about sound than technical playability. 

While the overstand does help the players, I wouldn’t say that there were too many choices for strings back in the 19th century to solve this problem.i Even still when I was a kid there were only a few options in strings. I don’t know when Pirastro introduced 7 different string thicknesses of their gut strings, but presumably not before 1900.

 

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19 hours ago, Andreas Preuss said:


 

I wrote somewhere else that I see in this connection the trend that workshops started to increase the neck overstand to flatten the string angle. This in return diminishes the down-force on the bridge bringing it back to the load with weaker strings. Long ago at the beginning of the 20th century 5.0 - 5.5mm overstand was a sort of standard on modernized instruments, nowadays we are at 6.0 - 6.5 and I wouldn’t be surprised if this goes even higher in future.

 

Hobbyhorse of mine I know, but increasing the overstand alone while retaining the neck angle will increase the string angle. In order to decrease the string angle and lessen the load, if the overstand increases you also have to bring the nut up disproportionately relative to the plane of the body.

I don't see any way of talking about this clearly except by specifying the overstand at a given string angle, or by specifying the overstand and the nut position.

You can have any amount of overstand and any string angle, depending on where the nut is.

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