Loudness vs.string tension

[ctanzio]

12 hours ago, LCF said:

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. 

How does one determine which of the many string modes should not be heard?

Our perception of frequency comes mostly from the first harmonic of the vibration. The other harmonics, although rapidly decreasing in amplitude relative to the first, define the TIMBRE of the sound. Visually, it is the shape of the waveform as it travels along the string. The higher frequency content contributes significantly to the perception of the tone's timbre.

I have yet to see a "theory" of timbre that holds up to a double blind test. The biggest challenge to design by harmonic content is that no one has ever published an accepted theory showing a solid relationship between harmonic content and a good sounding violin.

When talking about damping, are we talking about internal damping only (mostly a thermodynamic effect), or are we including losses due to sound radiation and energy transfer to the violin? All contribute something and in dramatically different ways.

When talking about vibration, are we talking about the decay of the string vibration, or a sustained note? Dramatically different effects.

Here is brief rundown of internal damping effects on a sustained note.

Damping is a percent decrease in vibration energy per *cycle* of vibration. So higher harmonics, which vibrate more times per second, undergo more energy loss per second than lower frequency harmonics.

Complicating this is the observation that the effective damping is frequency dependent. For violin string materials, higher frequencies experience lower damping coefficients. This tends to offset the rate of energy loss of higher harmonics.

For a sustained note, the bow continuously drives a range of harmonics. One has no choice but to experience a great many harmonic modes of vibration, whether they want to or not.

There is an inharmonicity effect that can be caused by the damping in some common violin materials. This is noticeable in higher harmonics. For example, perlon core strings can display frequency drift for harmonics over the 5th harmonic by 10 cents or more, where a metal core string might have harmonic drift of 1 cent or less at higher harmonics.

Is this good? Is this bad? >shrugs< It does mean the timbre of the note produced by a perlon string is different than that of a steel core string. 

[LCF]

14 minutes ago, ctanzio said:

How does one determine which of the many string modes should not be heard?

Our perception of frequency comes mostly from the first harmonic of the vibration. The other harmonics, although rapidly decreasing in amplitude relative to the first, define the TIMBRE of the sound. Visually, it is the shape of the waveform as it travels along the string. The higher frequency content contributes significantly to the perception of the tone's timbre.

I have yet to see a "theory" of timbre that holds up to a double blind test. The biggest challenge to design by harmonic content is that no one has ever published an accepted theory showing a solid relationship between harmonic content and a good sounding violin.

When talking about damping, are we talking about internal damping only (mostly a thermodynamic effect), or are we including losses due to sound radiation and energy transfer to the violin? All contribute something and in dramatically different ways.

When talking about vibration, are we talking about the decay of the string vibration, or a sustained note? Dramatically different effects.

Here is brief rundown of internal damping effects on a sustained note.

Damping is a percent decrease in vibration energy per *cycle* of vibration. So higher harmonics, which vibrate more times per second, undergo more energy loss per second than lower frequency harmonics.

Complicating this is the observation that the effective damping is frequency dependent. For violin string materials, higher frequencies experience lower damping coefficients. This tends to offset the rate of energy loss of higher harmonics.

For a sustained note, the bow continuously drives a range of harmonics. One has no choice but to experience a great many harmonic modes of vibration, whether they want to or not.

There is an inharmonicity effect that can be caused by the damping in some common violin materials. This is noticeable in higher harmonics. For example, perlon core strings can display frequency drift for harmonics over the 5th harmonic by 10 cents or more, where a metal core string might have harmonic drift of 1 cent or less at higher harmonics.

Is this good? Is this bad? >shrugs< It does mean the timbre of the note produced by a perlon string is different than that of a steel core string. 

Fletcher and Rossing 'physics of musical instruments' 2nd ed  10.4.4 ' longtitudinal and torsional motion. 

Spend some time bowing along the string instead of across it. You usually don't want to hear that stuff unless you are of the avant garde. Guitar makers get very picky about scale lengths for related reasons. Longtitudinal modes are beam-like modes. 

Also sec 2.10 'Bowed String' for ref to damping the ephemeral part of the Helmholtz wave.

 

Conditions apply.

[LCF]

39 minutes ago, Aston4 said:

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

 

 

I played one. There is a small horn which faces the player so you can hear yourself. Fortunately it can be removed. 

[LCF]

1 hour 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.

 

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.

ITMS.

In acoustic models mass behaves similarly to inductance in electronics. It is reactive. Adding huge amounts of it moves a lot of the resonances downwards. Lots of ways if thinking about it. 

[David Burgess]

1 hour ago, Aston4 said:

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.

I think it's pretty simple. The bridge and the violin don't move as much at frequencies within the violin's audible output range. Less motion, less sound.

[David Burgess]

5 hours ago, reguz said:

They are repeating themselves loudly.

So are you. We've heard it all before.
You repeat, we repeat our responses. Why would you expect it to be otherwise?

[reguz]

Much can be described by words. But it is what is done by practical work that make it visibel. So, take a look and try to understand.

 

For Maestro.docxFor Maestro.docxFor Maestro.docx

 

[reguz]

David, you do not need to repid yourselve. People know that you cannot understand what it is about.

[Aston4]

1 hour ago, ctanzio said:

There is an inharmonicity effect that can be caused by the damping in some common violin materials. This is noticeable in higher harmonics. For example, perlon core strings can display frequency drift for harmonics over the 5th harmonic by 10 cents or more, where a metal core string might have harmonic drift of 1 cent or less at higher harmonics.

 

!!!!!!

!!

!

Explains a LOT about what I've been hearing and trying to parce out in my brain, experimenting with different string types, and different fiddles and bridges. Is it known whether the violin body itself, or the bridge, or anything else (shoulder rest) can cause frequency drift too?  I suspect unlikely, but I don't know.  I was doing a bit of spectral analysis, but didn't do enough obviously.

 

It seems fairly obvious to my hearing that different violins will tend to amplify or dampen either odd, or even, higher harmonics, or both.  I never considered that any frequency drift was occurring.

[Aston4]

42 minutes ago, David Burgess said:

I think it's pretty simple. The bridge and the violin don't move as much at frequencies within the violin's audible output range. Less motion, less sound.

A light mute seems to knock out mostly high frequency, a heavy mute seems to knock out low frequency as well.  I think the above reply relating it to inductance is probably correct, but I don't have much of an electrical engineering background, and though I once had a OKish understanding of simple circuit design, alas, it is lost.

Then of course there are those little slidy squishy things with little lumps of brass inside of clear tubing.  Do they even make those any more?  The tubing, I remember, was actually pressing on the strings directly, even a little bit in front of the bridge.

 

ETA: still made

[David Burgess]

18 minutes ago, Aston4 said:

Then of course there are those little slidy squishy things with little lumps of brass inside of clear tubing.    The tubing, I remember, was actually pressing on the strings directly, even a little bit in front of the bridge.

The part where the "axle" goes through the brass inserts on the ends will actually be touching the bridge.

[Michael Darnton]

2 hours ago, LCF said:

I think certainly yes,  I acknowledge  those possibilities since various resonances can kick in dramatically when coupled, since resonance is a very  powerful effect.

It's probably a mistake to separate the idea of resonance coupling through the bridge and say that's broad band and important and then to deny that when it's coming from the neck. I can tell you from experience that the effects of the neck and it's connection to the body change the character of the instrument much more than changes you can effect through the bridge, throughout the spectrum, in very fundamental ways. As in completely changing one instrument into another. Not a minor effect at all and something that I use a lot. Not talking here about the famous strategy of "tuning" fingerboards by scraping bits of dust off them.

[Anders Buen]

50 minutes ago, reguz said:

David, you do not need to repid yourselve. People know that you cannot understand what it is about.

https://www.google.com/search?q=youtube+allo+allo+policeman&sca_esv=36d7d91555c12cff&sca_upv=1&rlz=1C1GCEU_noNO1062NO1062&sxsrf=ACQVn0-87AJrNL8BZGRRpzLal_yRsTW0_g%3A1712157641647&ei=yXMNZvCCJ9yP1fIPtt62qAk&udm=&ved=0ahUKEwiwi56grKaFAxXcR1UIHTavDZUQ4dUDCA8&uact=5&oq=youtube+allo+allo+policeman&gs_lp=Egxnd3Mtd2l6LXNlcnAiG3lvdXR1YmUgYWxsbyBhbGxvIHBvbGljZW1hbjIIEAAYgAQYywFI4iBQqAVYoRhwAXgAkAEAmAGoAaABlAeqAQQxMC4xuAEDyAEA-AEBmAILoAL3BsICChAAGEcY1gQYsAPCAgUQABiABMICBhAAGBYYHpgDAOIDBBgAIGqIBgGQBgiSBwQxMC4xoAe1Gg&sclient=gws-wiz-serp#fpstate=ive&vld=cid:af5ac6be,vid:y1aknvtLJa0,st:0

[Dr. Mark]

2 hours ago, reguz said:

Much can be described by words. But it is what is done by practical work that make it visible. So, take a look and try to understand.

You may have to accept it that people contributing to this thread are simply too distracted or disinterested to accept that your STL conviction is relevant.  That being the case, it seems foolish to place yourself in a position where you receive little other than negative reactions to your posts.  You can't force ideas on people however good the idea is, however much you insist - in fact, however much valid evidence you may be able present.

What would serve you better I would think is to gather together the people who will take your proposals seriously.  To do this you almost certainly want to start a separate thread which those willing to discuss your ideas with you can engage in by choice.  Everyone would seem to gain by your doing so.

Given all of this, continuing to post about STLs and arching will suggest that you have another motive than a constructive contribution to this particular discussion.   I don't intend this post to initiate yet another tangential discussion and won't engage further on this topic.

[David Burgess]

3 hours ago, reguz said:

David, you do not need to repid yourselve. People know that you cannot understand what it is about.

Yup. Sure thing. Whatever you think "floats your boat" must be true.

[jezzupe]

1 hour ago, Dr. Mark said:

You may have to accept it that people contributing to this thread are simply too distracted or disinterested to accept that your STL conviction is relevant.  That being the case, it seems foolish to place yourself in a position where you receive little other than negative reactions to your posts.  You can't force ideas on people however good the idea is, however much you insist - in fact, however much valid evidence you may be able present.

What would serve you better I would think is to gather together the people who will take your proposals seriously.  To do this you almost certainly want to start a separate thread which those willing to discuss your ideas with you can engage in by choice.  Everyone would seem to gain by your doing so.

Given all of this, continuing to post about STLs and arching will suggest that you have another motive than a constructive contribution to this particular discussion.   I don't intend this post to initiate yet another tangential discussion and won't engage further on this topic.

"and won't engage further on this topic."  "We've" been saying that for years

give a monkey a brain and he'll swear to god the sound post is the center of the universe

[LCF]

6 hours ago, Michael Darnton said:

It's probably a mistake to separate the idea of resonance coupling through the bridge and say that's broad band and important and then to deny that when it's coming from the neck. I can tell you from experience that the effects of the neck and it's connection to the body change the character of the instrument much more than changes you can effect through the bridge, throughout the spectrum, in very fundamental ways. As in completely changing one instrument into another. Not a minor effect at all and something that I use a lot. Not talking here about the famous strategy of "tuning" fingerboards by scraping bits of dust off them.

It is difficult to parse. Do the effects lessen as you play higher up the neck?

I'll point out that I said nothing much happens wrt string vibration past the nut. You can muck around with the exposed string portions in the pegbox and not find much going on. I do think there's a lot going on in the wood of the neck and fingerboard considered as a part of the whole body but very little happening at the afterlength end of the bridge wrt string vibration. Btw @ctanzio by 'vibration' I'm referring, as is customary to lateral bending waves, the ones that produce the majority of violin-like sounds. 

We arrive back at Evan's ideas about the B-1 resonance mode somewhere around here. 

 

 

[LCF]

6 hours ago, Aston4 said:

A light mute seems to knock out mostly high frequency, a heavy mute seems to knock out low frequency as well.  I think the above reply relating it to inductance is probably correct, but I don't have much of an electrical engineering background, and though I once had a OKish understanding of simple circuit design, alas, it is lost.

Then of course there are those little slidy squishy things with little lumps of brass inside of clear tubing.  Do they even make those any more?  The tubing, I remember, was actually pressing on the strings directly, even a little bit in front of the bridge.

 

ETA: still made

That is what I think of as a sliding mute. The metal  adds mass and the plastic adds some damping. 

The effect of mass is frequency dependant and also depends on the amount of it.  Higher frequency, more effect. More mass, more effect and more effect at lower frequencies.

Those heavy clip-on mutes also give the strings much more sustain.

 

[LCF]

Resonance at work. 

 

https://cdn.ca.emap.com/wp-content/uploads/sites/13/1968/07/GE-July-1968-Vibratory-pile-driving-part-1-the-resonant-pile-driver.pdf

[Michael Darnton]

1 hour ago, LCF said:

It is difficult to parse. Do the effects lessen as you play higher up the neck?

I'll point out that I said nothing much happens wrt string vibration past the nut. You can muck around with the exposed string portions in the pegbox and not find much going on. I do think there's a lot going on in the wood of the neck and fingerboard considered as a part of the whole body but very little happening at the afterlength end of the bridge wrt string vibration. Btw @ctanzio by 'vibration' I'm referring, as is customary to lateral bending waves, the ones that produce the majority of violin-like sounds. 

We arrive back at Evan's ideas about the B-1 resonance mode somewhere around here. 

 

 

I think it's all semantics at this point. The endpoints aren't really different than the bridge: the strings wiggle the bridge and things beyond and they wiggle the nut and things beyond. It's the nature of how the instrument works, and each area has its own influence.

No, effects don't lessen up the neck.

[LCF]

2 hours ago, Michael Darnton said:

... It's the nature of how the instrument works, and each area has its own influence.

No, effects don't lessen up the neck.

Thanks.

Yep, stuff happens then people do stuff.

I plead slightly increased levels of insanity under provocation. 

[ctanzio]

5 hours ago, LCF said:

Iby 'vibration' I'm referring, as is customary to lateral bending waves, the ones that produce the majority of violin-like sounds.

Just be aware that violin strings do not vibrate in a purely planar fashion. There is vibration out of the plane of the bow motion which gives the string motion an elongated oval-like appearance. One of the drivers of this is torsion about the length of the string introduced by the bow. This can cause some very obvious sounds, like a whistling on the E string or a buzzing on thicker strings.

[Aston4]

13 hours ago, LCF said:

I played one. There is a small horn which faces the player so you can hear yourself. Fortunately it can be removed. 

In the videos I could find, it sounds non-pleasing.  I understand the point, but obviously better to add more more regular fiddle players for more volume when needed than that thing.  Seems that idea has not been fully explored yet though.  For example, I heard a dobro (I think that is what it is called) guitar up close the other day.  I thought it would sound harsh and metallic.  I was surprised it sounded warm and enveloping.

[LCF]

1 hour ago, ctanzio said:

Just be aware that violin strings do not vibrate in a purely planar fashion. There is vibration out of the plane of the bow motion which gives the string motion an elongated oval-like appearance. One of the drivers of this is torsion about the length of the string introduced by the bow. This can cause some very obvious sounds, like a whistling on the E string or a buzzing on thicker strings.

It's a real mess but it seems that what has evolved does everything it can to make it less of a mess. 

[LCF]

On 4/3/2024 at 11:52 AM, 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?

 

 

Marty, how thick are your Pawlonia boards usually, or are you using birch?