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When you are tuning plates you can do it any time.

Years ago when I tuned plates, after mine were finished and didn't work too well...

so then I would take them apart and tune some more. It used up a lot of time and mental energy.

Until (or IF) I figure out an accurate way to determine the assembled instrument character from the free plates, I'll continue to use extremely thin glue on the top for the initial assembly. It's no big deal to pop the top off and re-glue it, even if no modifications are necessary. Thus far, only #2, #4, and #10 have gone together without subsequent modifications (but I'm a habitual modifier, and usually doing something unusual in the first place).

I suppose I could do the external regraduation thing, but I like to know where I am thickness-wise (and I don't have a Hacklinger gage), and as I said, it's no biggie to remove the top.

In my opinion, the free-plate properties of the top without the bass bar seem to be more predictive of what happens in the assembled instrument, as long as the bass bar is made somewhere near normal proportions.

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For the last couple of violins I made no changes to the instrument. These were commissioned instruments and the owners were completely happy with the sound of the instrument when it was completed.

Don Noon wrote:

I suppose I could do the external regraduation thing, but I like to know where I am thickness-wise (and I don't have a Hacklinger gage), and as I said, it's no biggie to remove the top.

Well, if you built violins the Cremonese way, inlaying the purfling and finishing the edgework from the outside, then needing to know the exact thicknesses would be laughable and impossible.

Here's an analogy that's right up your alley. If you wanted to get a rocket to the moon, would you shoot it like a shell from a cannon aiming for the planet or would you equip your rocket with a guidance system so you could make mid course corrections?

As I see it, 'acceptable sound' is a pretty big target which can be achieved by choosing mid range wood, following standard arching and graduation patterns. But if you are aiming for something more precise or if you are encountering a specific acoustic problem, then you need a 'guidance system' to hit your target. That's where a method for identifying the tonal properties of a region on a playable violin becomes important. Removing the top and hoping to remove just the right amount of wood from just the right place is like shooting at a target with your eyes closed facing the wrong direction.

There are limits to what you can accomplish with external mods. the rule of 'Silk purses and sows ears' applies.

Oded

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But if you are aiming for something more precise or if you are encountering a specific acoustic problem, then you need a 'guidance system' to hit your target. That's where a method for identifying the tonal properties of a region on a playable violin becomes important. Removing the top and hoping to remove just the right amount of wood from just the right place is like shooting at a target with your eyes closed facing the wrong direction.

I have no problem identifying acoustic problems and the associated modes that cause them, and many others have that capability now, too, using various methods. However, I have yet to see anyone (myself included) show a successful complete process where a specific problem was identified, the goal stated, and the result matched the goal, without causing undesirable side effects. I don't want to take this debate farther down the old well-worn road, but if you have such a method, please convince us with objective evidence rather than talk about it.

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I have no problem identifying acoustic problems and the associated modes that cause them, and many others have that capability now, too, using various methods. However, I have yet to see anyone (myself included) show a successful complete process where a specific problem was identified, the goal stated, and the result matched the goal, without causing undesirable side effects. I don't want to take this debate farther down the old well-worn road, but if you have such a method, please convince us with objective evidence rather than talk about it.

I don't know that 'objective' evidence is the metric to use. For instance, I've clearly heard soundpost adjustments that simply were not evident in any objective test available.

As for a subjective evidence I have loads of observers and participants who have experienced this first hand including a renowned musician who states that he saw an improvement in 'complexity' of an instrument.

Complexity is one of those qualities that are hard to pin down with an 'objective' test.

As far as collateral damage in the form of undesirable side effects, one can pick and choose. For instance if I want to bolster a particular frequency, I can see the other resonances for that spot and choose whether I want to generally lower or raise the timbre of the instrument. It is not perfect there is always some element of randomness but it seems to me a much better 'guidance system' than anything else out there.

Look, I don't try to bring up this stuff, nor am I interested in becoming a religious evangelist on this point. I will simply say that it's all too easy to be a skeptic, yet the logic and simplicity of modifying the sound from the outside is unassailable and has been suggested by virtually all the major writers on violins from the Hills to Saconni to Hargrave to Rogers. My modest little addition is to suggest that there is a simple method to predict, more or less, the effect of the change.

I agree, let's not further trample the nice new grass that has grown along this little path. I'm perfectly happy to agree to disagree. :)

Oded

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Hello. I am a new member to maestronet so forgive me if I ask a redundant question. I am curious if anyone has any opinions concerning the information offered up on Platetuning.org. I mean no disrespect to the website itself or anyone who may be connected with it. Actually, it is full of useful links and the like, but I am wary of ´hard and fast´rules as they apply to this subject.

Welcome, Mike! :)

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I'm pretty much at the beginning of the road, so I'm more relying on reading, logic, and intuition. Undoubtedly, experience will likely modify my methods.

So for now though, I tap a bit -- just not for specific pitches.

Some logical reasons not to believe tuning to specific pitches can be right:

The old guys apparently didn't make specific instruments for specific local pitch variations.

I'd expect this to be a problem if violins needed particular plate tuning to be good.

Repairs and restorations and regrads would change the tuning, as would loss of varnish.

So if the tuning was critical, instruments should historically go in and out of being good.

Instead, it seems that good instruments mostly just get better with time.

There doesn't appear to be any strong correlation between results and tuning among modern makers.

Not likely that the old masters were reading Catgut Society, Fetis, or similar.

But in support of the general notion of tapping:

Listening to the wood while carving seems a natural thing to do.

The writings and ideas of Roman author Vitruvius were in circulation.

Apparently they were even rather in vogue when the violin arose.

Vitruvius discusses both resonances and tapping, though in somewhat different context. He talks about intentionally placing large urns and building in cavities throughout an amphitheater for the sake of resonances. He also talks about tapping as a way to determine equal tension in building something like a cross bow. So the idea that the old makers might have had some ideas and practices along the general line of tapping doesn't seem unimaginable. But tapping combined with microphones, scopes, computers, and numerical analysis? That seems vary far removed from the old masters. In their day, numbers and music mostly only connected in the relationship of harmonious intervals to simple integer proportions.

So for me, I do a little tapping to help me find asymmetries in the response of the plate, and later the instrument. But I'm not looking for a particular pitch, just balanced responses.

Myself, I'm more interested in the Q of the taps than their pitch (broadness or sharpness of the resonance). I want an instrument with resonances that respond to the player, not with with such specific resonances that they pop out in and out. So I'm happy to hear lively but broader and less pitch defined taps.

David

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Does anyone plate tune before the bass bar is put in? Or is tuning always done after the bar is put in?

When regraduating an existing top with F-holes and a bassbar, I remove the bassbar and bring the top's thickness down to my target specs, whether the specs be a thickness map or specific taptones, then I install a new bassbar. The new bassbar will make the Mode 5 taptone skyrocket, so I then carve the bar to shape and stop when I get the Mode 5 taptone back where I want it. Sometimes a little adjusting has to be done to Mode 2 as well. When making a new top, I get the M2 and M5 taptones where I want them before I cut the f-holes or install the bassbar. That gets the inside arch about right for the bassbar. I cut the f-holes, install a new bassbar, and re-tune the taptones by stopping cutting the bassbar when the mode 5 taptone is where I want it.

My experience has been that I can put the Mode 5 taptone wherever I want it (260 hz to 400hz) by installing and carefully trimming a new bassbar.

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  • 4 weeks later...

I agree with Bill: you just have to get the thicknesses and M2 and M5 (particularly M5) of the belly plate about right before the bassbar is put in.

Then, oh then the real work starts: you carve the bassbar's shape, the height and the balance (match) of the height at the 2 ends to give that full M5 ring. Sometimes, or more often than I would like, it takes 2 + tries (i.e. 2 bars) to get it right. If the back's thick, the belly needs to be rather thick too, with slightly higher M5 than normal. So for me tap tones help: I'm 35 years short of the short of the 40 years it takes to know what to do without tap tones!

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Here's an analogy that's right up your alley. If you wanted to get a rocket to the moon, would you shoot it like a shell from a cannon aiming for the planet or would you equip your rocket with a guidance system so you could make mid course corrections?

Oded

Actually I thought they did shoot it like a cannon (only not pointing at the moon, but calculating where the rock and moon would collide and aiming for that). The reason being that once in space there is no pressure, or air, and you need both to propel a rocket. Once out of the atmosphere, and away from the Earths gravity, all spacecraft will just float at the same pace until they are pulled by another gravitational force.

I could be entirely wrong though.

But I do agree that using objectivity in violin making is redundant after a point. It is useful if you want to know something specific (soundspeed in wood, for example), which may be of benefit (eg looking for greater volume and response requires wood with x density)but it is also limiting, in that the purpose of the violin (to make music) is entirely subjective, and in this sense there are many variables and no real 'right or wrong'.

In this sense I rely heavily on 'Empirical science'. Doing something consistently, examining the results, make small changes and examine the results. Better or worse? what happened? What changed?

Do it again. Same result? if not why not? etcetera etcetera ad infinitum.

Also, sometimes a goal is involved eg instrument is too soft, uneven, one note is jumping out. Then you need to examine the evidence, nut out the possibilities and start making adjustments taking notes of not only whether you are closer or further from your target, but also what else changes (coz there's always something). After doing this a thousand times you gain a better understanding of how the sound moves through the violin in a very complicated way.

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One of Newton's laws. For every action there is an equal and opposite reaction. If you expell rocket exhause out of a nozzle then the spacraft will move in the opposite direction. The fuel contains it's own oxidizer so it does not need oxygen or an atmosphere. It even works better in a vacum because there is no friction.

So if you tap tune a rocket will it fly better? Had to stay on topic somehow.

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Rocket science is too simple to be debating on MN. Let's save the space for the more complicated topic of violin acoustics.

But, yes, rockets work fine in a vacuum. Efficiency is of extreme importance, which often involves enerty-saving tricks like close planetary swingbys to get where you want to go.

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The original question is: do rockets have guidance systems that allow for adjustments in transit, or are rockets simply aimed, albeit strategically, at their target?

The analogy being that this is an apt comparison to making violins, where some form of adjustment can be made, preferably before the instrument is finished, to more accurately 'hit the target'.

Oded

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Rockets or violins, you always take your best shot at the start. For interplanetary work, the goal is impossible to hit with the inaccuracies of the initial shot, so there is always the occasional course correction along the way (tracking and commands from the ground). Oded and I both find that the initial assembly of the violin may need some correction; he adjusts from the outside, I prefer the inside. The last time I was at Oberlin, a previous VSA gold winner had a newly built instrument (complete and varnished), and after some discussion he concluded he needed to reduce the bassbar height (no big deal, just pop the top.)

On my last violin, I did not need to adjust anything. That will have to happen much more consistently before I change my routine of in-the-white testing and adjustment. If I continue to use the most extreme range of wood properties, I expect more error on the first shot. Perhaps my luck on #10 was because I used top wood from the same log as #9? Don't know yet... but could be.

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One of Newton's laws. For every action there is an equal and opposite reaction. If you expell rocket exhause out of a nozzle then the spacraft will move in the opposite direction. The fuel contains it's own oxidizer so it does not need oxygen or an atmosphere. It even works better in a vacum because there is no friction.

So if you tap tune a rocket will it fly better? Had to stay on topic somehow.

I read that Newton's law says "For every phD there is an equal and opposite phD."

Violins follow physics laws so this is basically why we often have opposite opinions.

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...Vitruvius discusses both resonances and tapping, though in somewhat different context. He talks about intentionally placing large urns and building in cavities throughout an amphitheater for the sake of resonances. He also talks about tapping as a way to determine equal tension in building something like a cross bow.

Hi David,

Any chance you could tell us where Vitruvius talks about tapping in connection with crossbow construction?

Thanks,

Ed

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...... Oded and I both find that the initial assembly of the violin may need some correction; he adjusts from the outside, I prefer the inside. The last time I was at Oberlin, a previous VSA gold winner had a newly built instrument (complete and varnished), and after some discussion he concluded he needed to reduce the bassbar height (no big deal, just pop the top.)

On my last violin, I did not need to adjust anything. That will have to happen much more consistently before I change my routine of in-the-white testing and adjustment. If I continue to use the most extreme range of wood properties, I expect more error on the first shot. Perhaps my luck on #10 was because I used top wood from the same log as #9? Don't know yet... but could be.

in the spirit of a friendly disagreement and furthering the discussion I offer the following.

I prefer adjusting from the outside but a strong argument can be made that either outside or inside adjustments are far better made to the assembled, playable instrument than taking the instrument apart in order to make adjustments. And there are multiple ways to remove wood from the inside of an instrument without removing the top.

The real question is where to remove the wood and how much wood to remove. I don't know the capability of modal analysis to predict tonal outcomes from removing wood, my understanding is that it is a weak predictor.

Yes, removing the top and regraduating the plate has been done countless times, sometimes it works and sometimes it doesn't. In either case it is basically a guess and a hit or miss proposition.

The fact of the matter is that when you remove a plate and thin it....

  • you don't know the effect until you reassemble the instrument.

  • There is a real risk of damaging the top.

  • You don't know the tonal effect of removing and re-gluing the top.

  • It is time consuming waiting for glue to dry.

  • The tone is more likely to change again with the drying of the glue.

  • The best you can do is guess where and what to change

I did not make any changes to my last two instruments and I've also been using the same log for the tops. I think there is a real advantage to doing this.

I personally know an 'hors concours' VSA medalist who routinely makes adjustments to the outside of his instruments in the white. No, I will not reveal his name. :rolleyes:

Oded

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Hi David,

Any chance you could tell us where Vitruvius talks about tapping in connection with crossbow construction?

Thanks,

Ed

It's Chapter XII of Book X, actually titled 'The Stringing and Tuning of Catapults'. Not exactly a match to modern 'tap tuning' concepts, but it does show an awareness of using tap sounds in order to balance tensioned systems.

Also seems very interesting that he mostly describes the critcal design elements in building various machines in terms of simple proportions.

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