Loudness vs.string tension

[LCF]

7 minutes ago, Aston4 said:

A violin is the set of points that are all at the same distance r from a given point in three dimensional space.  That given point is the center of the violin, and r is the violin's radius.

So the equation works damnit.

Where's the glue in that?

[Aston4]

1 minute ago, LCF said:

Where's the glue in that?

Glue is made from the outer surface of spheres.

[LCF]

8 minutes ago, Aston4 said:

Glue is made from the outer surface of spheres.

Mu-glu?

[Aston4]

31 minutes ago, LCF said:

Mu-glu?

dude. 

 

 

we could hang out.  too bad you're on the other side of the cow

[Dr. Mark]

22 hours ago, Aston4 said:

The answer is here:

mu is energy.  T is tension.

https://users.physics.ox.ac.uk/~palmerc/Wavesfiles/Energy_Handout.pdf

 

That [paper] looks similar to a draft analysis authored by Felix Parra in 2021 (also at Oxford), the following year, the latter including some diagrams: https://www-thphys.physics.ox.ac.uk/people/FelixParra/waves/notes/note3_energy.pdf. 

I'd expect that you know of a relationship between the intensity of violin's emission and the string tension if you're going to make the claim that the potential energy in an increment of stretched string is the answer.

 

[David Burgess]

8 hours ago, LCF said:

... except when you suck some of the energy out of it at one end namely via a violin bridge and onwards into the corpus, then the boundary conditions change in a very complex way and the assumptions made for the basic string equation are not valid.

Agreed. The bridge on an acoustic violin is not a fixed endpoint and doesn't behave like one.

[ctanzio]

10 hours ago, Aston4 said:

This is the ACTUAL ANSWER.  It is not speculation.  It is physics.

It is a theoretical expression for the *potential* energy stored in an ideal vibrating string at any small segment at some point in time. In terms of energy being driven into a violin, it does not answer anything related to loudness and string tension.

You want the kinetic energy being driven into the bridge over one cycle. Then sum it up for all the harmonic cycles of the string to get some estimate of the energy per unit time (power) available to drive the bridge.

And even then you only have an estimate. The paper makes a few assumptions to "simplify" the equations that might not be true for a violin string stretched over a violin.

For example: change in string tension as the string vibrates, damping effects in the string, twisting (string torsion), vibration out of the plane of the bowing, and the nonsymmetrical shape of the wave traveling along the string.

Just to name a few. >grin<

 

 

 

[Dr. Mark]

16 hours ago, Aston4 said:

A violin is the set of points that are all at the same distance r from a given point in three dimensional space.  That given point is the center of the violin, and r is the violin's radius.

...and that is ultra-funky.  You're just pulling a surface bait across the lily pads.

[LCF]

11 hours ago, ctanzio said:

... And even then you only have an estimate. The paper makes a few assumptions to "simplify" the equations that might not be true for a violin string stretched over a violin.

For example: change in string tension as the string vibrates, damping effects in the string, twisting (string torsion), vibration out of the plane of the bowing, and the nonsymmetrical shape of the wave traveling along the string.

Just to name a few. >grin<

 

 

Neville Fletcher made the point that violin strings work best when they have relatively high damping so that some of the many modes of string oscillation which  we don't want to hear get more damped. 

It seems obvious to me that the shape of the bridge with high rigidity in the X direction (crossways) has a fairly efficient  rocking lever action which amplifies the bending string modes (the bow-pluck direction) but has very little capacity to amplify the lengthways string modes in the Y direction since it so thin and has no leverage over the soundboard. Those longtitudinal modes are pretty horrible sounding things and not harmonically related to much of anything else. Bowing lengthways tends to excite more of them giving rise to the learner's screech. 

 

The most obvious  thing sitting right in plain view which always makes strings wildly inharmonic is having the bow sit on top of them. Same effect as a big lump of bluetac sitting there.  It's the very complicated dynamics of the bow-string interaction which generates tones with phase locked harmonics.

 

[Marty Kasprzyk]

I'll try making a lighter top plate on one of my small violas to increase its sound output.  The original plate's weight is 64.5g and the new one will be about 55g.

If you just play the same notes on the A,D, and G strings has anybody ever compared the loudness of violins vs. violas?

 

 

[Aston4]

25 minutes ago, Marty Kasprzyk said:

I'll try making a lighter top plate on one of my small violas to increase its sound output.  The original plate's weight is 64.5g and the new one will be about 55g.

If you just play the same notes on the A,D, and G strings has anybody ever compared the loudness of violins vs. violas?

 

 

Sitting in a standard orchestra layout, from the violin area, violas always sound very quiet.  If I ever hear them at all.  Come to think of it, in a quartet there isn't much viola sound there either, easily overpowered by violin or cello.  

[LCF]

3 hours ago, Aston4 said:

Sitting in a standard orchestra layout, from the violin area, violas always sound very quiet.  If I ever hear them at all.  Come to think of it, in a quartet there isn't much viola sound there either, easily overpowered by violin or cello.  

Sometimes you notice it more when it isn't there. 

[LCF]

5 hours ago, Marty Kasprzyk said:

I'll try making a lighter top plate on one of my small violas to increase its sound output.  The original plate's weight is 64.5g and the new one will be about 55g.

If you just play the same notes on the A,D, and G strings has anybody ever compared the loudness of violins vs. violas?

 

 

In terms of the wolfiness of the board versus the gauge of the strings this makes a great deal of sense to me, which may or may not be a worrying developement  

[reguz]

What is the difference between a loudspeaker and the violin as I come to producing sound?

Well, if the cone of the speaker does not move, we do not hear any sound.

 

Sound becomes produced when the cone starts moving = vibrating.

So, it also is with the violin. The source of frequency comes from the string but ALSO the the dynamic movement comes from the strings when they act at the end blocks.

The frequency source must be very stable and that is why it is that close the sound post while the action on the end blocks is as far away from the sound post.

What we see structural are two bout shapes that have restricted area. That are comes from the the sector shape by the STLs and the curved-out line. This structure by spruce has many different winter grown wood that has limited length-curvature-thickness. Thus, many we can say beams.

Each such beam responds on and may vibrate with a specific frequency—the frequency that is put in the structure under the bridge feet.

If the structures on the two bout shapes have equal structure, they may start producing the frequency that make the sound.

Many such beams together as a bundle respond on specific frequency. That may shift when another produced frequency on the string gives another input under the bridge feet.

Deoending on the stiffness of the bout shapes the “SPRING” condition of the bout shape me respond by vibrating. That is a dynamic condition that do not produce sound but will do when the stiffness of the “beams”--”respond” by becoming more or less dynamic making the sound based on the “Breathing” structure by the “spring” function.

So, what must become discussed is the shape and function of the arching.

What do we know as it comes to undelaying geometric described shape. First when we know that quality, we can start manipulating making it function optimal

So, by manipulating the the stiffness of the beams and increasing the basic dynamic behavior sound becomes produced more or less.

That is also what happens in a simple loudspeaker produce by the amplifier that produce the power.

[martin swan]

7 hours ago, Marty Kasprzyk said:

I'll try making a lighter top plate on one of my small violas to increase its sound output.  The original plate's weight is 64.5g and the new one will be about 55g.

If you just play the same notes on the A,D, and G strings has anybody ever compared the loudness of violins vs. violas?

 

 

I have often written string quartet parts and tried recording a line on violin and viola. I don't think there's a generalized difference in how they peak on the meters, but the audibility in context is completely different.

So once again, unless you define what you mean by "loudness" you could be barking up the wrong tree.

 

[David Burgess]

5 hours ago, reguz said:

.................

Haven't you found a more productive hobby yet? Perhaps shuffleboard or bingo?

[Aston4]

Is there any string strong enough that a cello could be brought up to violin pitch?  What would that sound like? 

[LCF]

5 minutes ago, Aston4 said:

Is there any string strong enough that a cello could be brought up to violin pitch?  What would that sound like? 

It would make a very short burst of sound as the neck collapsed inwards and the tailpiece flew up to clip you on the schnoz. 

[LCF]

2 hours ago, reguz said:

The source of frequency comes from the string but ALSO the the dynamic movement comes from the strings when they act at the end blocks.

 

It seems likely that you have never actually measured this so it will come as a complete surprise to you - there is very little normal 'vibration' from a violin string which gets past either the nut or the bridge. It stops pretty well dead at both of those. So your basic concept is incorrect. 

For example you can have a sliding mute sitting quite close behind the bridge and will make little difference to the sound until you put it right on top of the bridge. 

 

[Michael Darnton]

@LCF I think you have missed something very important there, but I am not the one with the research in hand to tell you. Maybe someone will stand up. But for a start, if you play you should try hanging a big clamp on a violin head and see if it makes a difference. There are important secondary effects from how the strings are anchored.

Some players would disagree with you about the effect of hanging mutes on strings, too. This would fall into the category of "If you can't hear it it's not real to YOU." Tailpieces, tuners, end guts. . .  all of these things have real effects from the musician's position.

Was anyone here personally involved in the internal wolfer hung on a rod through the end pin that I heard was done at Oberlin Acoustics more than a decade ago? Funny story, if I heard it right from someone who was there.

[reguz]

There people that really want to learn something and participate in a discussion.

There are also people that have or not have interest in learning more than they already know.

We also have people that do not play the instrument but like other to play Bingo and Shuffleboard.

They are repeating themselves loudly.

If there is any one that have studied the shape of and arching and its quality that is important for the function of it how it works on an instrument in static load condition and finally the dynamic behavior of that shape?

Please make you name know so we can have a discussion.

I have quite good knowledge how the arching I constructed works.

How is it with your arching?

[LCF]

1 hour ago, Michael Darnton said:

@LCF I think you have missed something very important there, but I am not the one with the research in hand to tell you. Maybe someone will stand up. But for a start, if you play you should try hanging a big clamp on a violin head and see if it makes a difference. There are important secondary effects from how the strings are anchored.

Some players would disagree with you about the effect of hanging mutes on strings, too. This would fall into the category of "If you can't hear it it's not real to YOU." Tailpieces, tuners, end guts. . .  all of these things have real effects from the musician's position.

Was anyone here personally involved in the internal wolfer hung on a rod through the end pin that I heard was done at Oberlin Acoustics more than a decade ago? Funny story, if I heard it right from someone who was there.

 

( Many apologies, this turned into long paragraphs. I'll banish myself for a while now.)

 

 

I think certainly yes,  I acknowledge  those possibilities since various resonances can kick in dramatically when coupled, since resonance is a very  powerful effect. Also wolf eliminators attached to the afterlength couple in order to work.  But i think those are all very special cases at specific frequencies and not the normal average situation. 

Put a little lead weight at the point where the tailpiece meets the strings - it will have some effects at various specific tailpiece resonance frequencies but not elsewhere ie it's not a broad band effect. Pluck some strings vigorously and move your hand to various parts of the afterlengths. Not much vibration to feel going on there and not much effect on the sound produced compared to the other side of the bridge, surprisingly little --- I really expected much more!   The dramatic amplifying nature of resonances is surprising and can turn very little energy into a big deal. 

 

One analogy I thought of is an old type acoustic gramophone pickup, the sort with the needle attached via some lever to a corrugated diaphragm housed in a heavy shell. I'm not making a loudspeaker analogy to a violin soundboard btw rather I am thinking of how, if the gramophone is sitting on a table and you are standing on the floor and you reach over and scrape the needle with a fingertip or a bit of paper without touching anything else you get lots of noise. You aren't connected to the gramphone by rods and springs or strings under tension. You are both in the same inertial frame and have much greater mass than the mobile part of the diaphragm and together make up a system with very low acoustic mobility. Someone might make a case for transfer of momentum perhaps?

 

Edited April 3 by LCF
Minor corrections

[Aston4]

1 hour ago, Michael Darnton said:

@LCF I think you have missed something very important there, but I am not the one with the research in hand to tell you. Maybe someone will stand up. But for a start, if you play you should try hanging a big clamp on a violin head and see if it makes a difference. There are important secondary effects from how the strings are anchored.

Some players would disagree with you about the effect of hanging mutes on strings, too. This would fall into the category of "If you can't hear it it's not real to YOU." Tailpieces, tuners, end guts. . .  all of these things have real effects from the musician's position.

Was anyone here personally involved in the internal wolfer hung on a rod through the end pin that I heard was done at Oberlin Acoustics more than a decade ago? Funny story, if I heard it right from someone who was there.

I never liked the sliding mute on the strings afterlength, because it damped the sound I could hear. I realized probably no one else could tell much difference, but still don't like it, it takes away from my joy of playing.  Of course I have left behind and lost many mutes.  Good thing mutes are cheap. Good thing there isn't a Pirastro Evah Mula $5000 mute that is the best sounding mute.  Yet.

 

ETA: Hmm.  There is something here.  A little mute, of little mass, mutes the sound a little.  The "big metal mute" I call it, nails the sound down HARD.  What exactly is going on here?  Easy to say "it just dampens the vibration of the bridge" or "more mass dampens more" but I suspect it gets into something complex about what the bridge does.

[LCF]

2 minutes ago, Aston4 said:

I never liked the sliding mute on the strings afterlength, because it damped the sound I could hear. I realized probably no one else could tell much difference, but still don't like it, it takes away from my joy of playing.  Of course I have left behind and lost many mutes.  Good thing mutes are cheap. Good thing there isn't a Pirastro Evah Mula $5000 mute that is the best sounding mute.  Yet.

I may have exaggerated a little to generalise my point but compare the effect it has when sitting at rest to the effect it would have if you put it on the other side of the bridge. Ergo not much at all is going on at the arse end of the strings. They are significantly disconnected. Strings wouldn't work properly otherwise, they wouldn't know where they ended. 

[Aston4]

25 minutes ago, LCF said:

 

 

One analogy I thought of is an old type acoustic gramophone pickup, the sort with the needle attached via some lever to a corrugated diaphragm housed in a heavy shell. I'm not making a loudspeaker analogy to a violin soundboard btw rather I am thinking of how, if the gramophone is sitting on a table and you are standing on the floor and you reach over and scrape the needle with a fingertip or a bit of paper without touching anything else you get lots of noise. You aren't connected to the gramphone by rods and springs or strings under tension. You are both in the same inertial frame and have much greater mass than the diaphragm and together make up a system with very low acoustic mobility. Someone might make a case for transfer of momentum perhaps?

I've never had my own gramophone to examine.  I did not know that is the working mechanism, how interesting.

 

What happens if you rest a gramophone needle on the bridge of a violin and play it?  Does the violin get louder?

 

ETA: I knew someone else must have thought of this.

 

And here it is:. 

 

https://en.m.wikipedia.org/wiki/Stroh_violin