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Andreas Preuss Super-Light-Violin Project


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10 hours ago, Jluthier said:

Thanks, so much Andreas, for sharing all your valuable observations!   I have been intrigued with making a lighter violin ever since I picked up a beautiful sounding 1963 Becker that feels to me like a feather.  Objectively, violin weights without chinrest: 

Andreas' light violin 302

Becker 1963, 377

Widhalm, 390 

Higgs' first violin 1989 ("the brick") 441.  

I wonder if anyone has had the top off a Becker to see how he & son did that.  

I am experimenting with internal bracing using square carbon fiber rods, which are extremely light and rigid.  So far this is the only variable I have added to the violin I am making, but I hope the bracing allows me to take weight of without loss of tone.  

Jay Higgs

Hi Jay,

I am glad that this serves as inspiration for other makers.

Initially my plan was really to beat the weight of carbon instruments telling myself, 'If I am a really capable craftsman, I can beat this.'

My current result shows that in principle it is possible, though this is not some sort of top notch sound machine. Weight, as I was warned at the beginning from some  knowledgeable MNetters, is not everything.

Therefore I slightly changed the path for this violin from 'super light' to 'new concept'. Before I was trying to reduce weight no matter how, now I am still looking at the weight, but if I find that it is benficial to add mass somewhere for the improvement of sound I will do it. 

Concerning the braces, I think they are a necessary element when weight is minimized on the ribs. 

There are other concepts I am reviewing now. Maybe a thinner top (too thin in a traditional sense) can be counterbalanced by a new type of bass bar. 

In the end building this violin was the best teacher in violin acoustics I ever had. It is a highly recommended 'etude' for anyone who is interested in violin sound production, overtones, bow response etc. etc.

PS. I still would be very curious to know to which weight Joe Curtin came down with his super light violin. 

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13 hours ago, Andreas Preuss said:

Weight, as I was warned at the beginning from some  knowledgeable MNetters, is not everything.

Minimizing weight is not everything.  But weight and distribution I think is very important.

If you could bring the weight down to zero, the whole instrument would wiggle but the plates would not deflect or pump air.

And although you could make a motorcycle with a better power/weight ratio by removing the flywheel, they still have 'em.

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8 hours ago, Don Noon said:

Minimizing weight is not everything.  But weight and distribution I think is very important.

If you could bring the weight down to zero, the whole instrument would wiggle but the plates would not deflect or pump air.

And although you could make a motorcycle with a better power/weight ratio by removing the flywheel, they still have 'em.

On a general scheme it looks like this:

When first finished the super light violin it was 317g, sound extremely woofy and basically unplayable.

First change to improve sound: reducing weight of the back from the outside: No major changes weight around 295g.

Second change: setting extremely heavy fernambuko neck. Weight c. 327g. No major improvements.

Third change: Back to normal sized linings on the topside. Can't remember exactly the weight but something like 2-3G more. (At the same time some of the vertical rib bracings came off and I didn't put them back) First major sound improvement. Still a boxy sound but playable. 

Fourth change: Doubling the linings. The first change which went away from 'normal' violin making practices. Sound improved to almost normal. Weight at c. 332g.

Fifth change: going back to a lightweight neck to reduce weight. No sound improvement expected. Weight down to c. 300g.

6th change: installing the Bayon bar adding 2g. No real improvement. More a shift of sound  to more 'roundness'. 

7th change: installing the cross bar. For what reason ever no measurable weight change. Boxiness somehow completely gone. Sound still on the dark side but with more grit (overtones). 

Summary: all significant changes stiffened the cross grain direction of the top. If the violin body is too loose in that direction it results in an unfocused boxy and woofy sound. At the same time this seems to prevent a good overtone range, but seems not to be entirely responsible for the optimal distribution of overtones. 

Right now there are two things I have in mind: correct the thickness of the back. There is a good chance that by thinning it down from the outside I went too far in the c bout region. So I would glue some patches there. 

Secondly make a bent top. This is more on the scheme same stiffness with less weight. Right now the top is 67g and it is even with a carved plate possible to get down to 60g (with BB). So maybe a bent plate can come down to 55g. 

Besides that there are a few changes playing around with some features: x shaped bass bar (I call it the spider bass bar) and adding a second cross bar below the ff. For both I expect however no dramatic changes for sound.

I am not a motorcycle fan but maybe in the history of motorcycle engineering the weight of the flywheel changed by accelerating its rotation speed? In the end I can't abandon necessary structural elements on the violin neither but recalibrate the entire body for the same sound functionality. To take the example of the motorcycle I suppose that a higher flywheel rotation results in different driving properties. (Faster acceleration?)

Addition: Being now down at 302g and having a violin of a functional sound it is the question if really 70g of additional mass is needed to make it sound really good. I guess not. What would be your guess?

Edited by Andreas Preuss
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15 hours ago, Andreas Preuss said:

Being now down at 302g and having a violin of a functional sound it is the question if really 70g of additional mass is needed to make it sound really good. I guess not. What would be your guess?

The real question is where you can do without mass and where you can't.

The basic soundbox (top, back, rib structure) I don't think you can whittle down too much without consequences.  Without too much effort, I think a good violin can have a soundbox in the 215-220g range, and with more effort and lower density wood, around 210g seems to be workable.  Going lower, down to 200g, I think you'll really notice the consequences.

You're left with attacking the neck and fingerboard to save weight, and that's where I think the consequences are more limited, mostly to the lower bending modes of the instrument.  The player might feel some difference, but less so for the sound.

So, no... I don't think you really need 70g additional mass to sound good.  But do you really need to take away 70g from a normal violin?  Seems like mostly solving a non-problem, and with any negative consequence for the player, I wouldn't go there..  However, for a viola, the problem is much more apparent, and the weight-saving techniques more applicable.  There's also the issue of how far you want to deviate from traditional materials and construction.  I don't want to get obviously deviant, so I limit my weight-saving (when desired) to lower-density wood and hollowing out the underside of the fingerboard.  Or once I grafted on a low-density scroll with high-density peg bushings.

 

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20 hours ago, Don Noon said:

The real question is where you can do without mass and where you can't.

That's exactly what I want try to find out. And therefore there are two options: you start with a normal violin and thin it down in certain areas to find out any differences or you go the other way and make it too light and eventually too thin and flimsy and see where the addition of mass (or rather stiffness) makes an audible difference. It's in the end like the 'gluey' experiment Sam Zygmontovitch has done before. 

I don't see mass as a 'problem'. When I started this project it was anyway only my intention to play around with the goal of light weight and see what is coming up.  However, now that I made this violin sound already pretty good,  I am thinking also about a sound calibration system with small weights and would assume a rather light violin is more sensitive for doing this.

Violin Restoration has added so many techniques to our repertoire and why not use it to make new instruments in combination with new materials. 

For the design, we should keep in mind that classical design patterns of Stradivari and Guarneei were made for music which didn't go beyond 5th position (not quite sure) but certainly did not use very high positions. I find it a sort of strange that this is accepted just with the argument 'there can't be any improvement.' I am saying 'yes there can be a better design, if we manouever cautiously to keep the balance between aesthetical appearance and acoustical necessities. I can only say that so far all violinists who thouched the super light violin liked the dropping shoulder and that the body feels short and handy. (The outline is diagonally in that direction 4mm shorter making it 347mm, that's almost 10mm less than a Strad pg model)

Lets see...

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2 hours ago, Andreas Preuss said:

I am saying 'yes there can be a better design, if we manouever cautiously to keep the balance between aesthetical appearance and acoustical necessities.

While I too think that some "improvements" can be made in reducing weight and making geometry more ergonomic, and perhaps do so without sacrificing sound and playability, my reading is that violinists almost exclusively want instruments that look exactly like normal traditional violins... no observable abnormalities.  Certainly there is a small percentage who want something unique and offbeat... and there are makers out there who cater to that niche... but personally I think that is a more difficult path to finding clients.  So my aim is for any improvements to be invisible.

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9 hours ago, Don Noon said:

my reading is that violinists almost exclusively want instruments that look exactly like normal traditional violins

Couldn't agree more. This is the very reason why my rule number one for changeing the design was: 

'If a violinist steps out on the stage people in the audience in the first row should not be able to notice a difference.'

My 'hero' in the field of successful form inventions is Hiroshi Iizuta who created his own fabulous viola model which got accepted by quite a number of viola players. 

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1 hour ago, Andreas Preuss said:

My 'hero' in the field of successful form inventions is Hiroshi Iizuta who created his own fabulous viola model which got accepted by quite a number of viola players. 

Just because someone succeeded in hiking to the South Pole doesn't mean that it's a reasonable path for others.

And hey... that's violas.  Doesn't count. :)

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  • 3 weeks later...

So now there are the latest changes.

I installed an x shaped bass bar and reduced the thickness of the top slightly in the upper half which reduced the weight of the plate from 61g to 56g. Then I made a second cross bar below the f-hole.

IMG_7833.thumb.JPG.4008399fde9d15440bbcb175a88a0dc2.JPG

The overall impression is that the sound became louder and crispier. If there was any negative effect the overall response became a little less. This means in my personal impression the instrument is a little harder to play and more attention is needed on bow speed, arm weight and location on the string. 

No changes in the general setup. weight didn't change either 300g now. (this means the second cross bar equals the weight reduction of the top.

I am planning to kick out the cross bars on the assembled instrument next to see if there is any effect.

Right now I am very happy about the sound. It is crisp has depth and can be played with a heavy bow arm. 

The graph before making the changes:

NCV44.thumb.jpg.52305d9b4fb913e3e339dec77247078d.jpg

and 2 days after the changes were made

1562102308_NCV45(2daysafterstringingup).thumb.jpg.b0930fa8e4d92085c801b684163329a5.jpg

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4 hours ago, Andreas Preuss said:

I installed an x shaped bass bar and reduced the thickness of the top slightly in the upper half which reduced the weight of the plate from 61g to 56g. 

weight didn't change either 300g now. (this means the second cross bar equals the weight reduction of the top.

So if the weight didn't change and you reduced the top plate by 5g, then the new bar is 5g heavier than the old bar, right?  And the old bar was a 7g Bayon bar?  So the new bar is 12g??  Or maybe the humidity is a lot higher now adding a lot of weight that isn't the bar.

BTW, I looked at the graphs before I read the words in the post, and my first thought was: "He must have thinned out the top."

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21 hours ago, Don Noon said:

So if the weight didn't change and you reduced the top plate by 5g, then the new bar is 5g heavier than the old bar, right?  And the old bar was a 7g Bayon bar?  So the new bar is 12g??  Or maybe the humidity is a lot higher now adding a lot of weight that isn't the bar.

BTW, I looked at the graphs before I read the words in the post, and my first thought was: "He must have thinned out the top."

Don, you are the genius in reading a sound graph! Now you must tell me from where you can see that I thinned down the top.

For the weight: the mass reduction of the top was replaced by a second cross bar in the interior. So the new x bass bar has just the same weight as the Bayon bar. 

Actually there is a slight mismatch because for the thinning of the top I measured minus 5g and the bamboo stick weights only 3.4g. So the X bar must be 8.6g but I don't think so. Right now there are no big changes in humidity in Japan. 

Right now I am weighting what change I should make next. Right now the fiddle sounds actually pretty good and I don't want to mess it up. (Before I was rather thinking: It doesn't sound anyway, so if it gets worse it doesn't matter...)

I actually removed yesterday the cross bars and reajusted the sound with new strings. Some of the woofiness  came back (will post the graphs later) but not in a very disturbing degree. However, if I can control this without the cross bars would be good. So I am thinking to open this time the back, because the linings on the back side became almost invisibly small when i reduced the rib height and should be replaced anyway. If heavier linings on the back can diminish the woofiness, then it is just fine, but I am skeptic that this will work. My reasoning is that woofiness comes from the frame the top is sitting on. Therefore the installation of the cross bars worked perfectly. If I try to achieve this from the back I don't think this is going to work very efficiently.

So after the operatons on the linings I am thinking of 2 options: Doubling the edge of the top to reinforce the frame or make a new top from bent plates. 

Addition: I mostly concerned about getting more resonsnace between 2kHz - 4kHz.

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13 hours ago, Andreas Preuss said:

Now you must tell me from where you can see that I thinned down the top.

So after the operatons on the linings I am thinking of 2 options: Doubling the edge of the top to reinforce the frame or make a new top from bent plates. 

Addition: I mostly concerned about getting more resonsnace between 2kHz - 4kHz.

 

The primary clue to a thinned top was the increased relative power in A0 and B1-.  

For increasing the high frequency output, I would avoid the split bass bar in the upper bout.  The lower bout is probably OK, but the upper bout is the strongest emitter of the higher frequencies, and adding constraints there probably is not a good idea.  If you really want more HF output, torrefied wood I think is a benefit, and perhaps bent plates (although I have never tried them).

 

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After I removed the two cross bars the sound of the violin became again boxier, BUT  not to a disturbing degree.1784050456_NCV47(upperlowercrossbarremoved).thumb.jpg.56cdfdab3cd1cec3b86e4e2aedac17be.jpg

 

Here I think it is getting really interesting. For the next alteration I trimmed the X shaped bass bar only in the upper half.

IMG_7868.thumb.JPG.049c01a74e7bf2fa1e77745b9b4ee121.JPG

When playing the instrument I noticed a sort of 'sizzle' in the sound which is usually  associated with very good instruments. All over the sound got more 'quality'. In short I am very happy about the last change.1174202212_NCV49Xbassbarinstalledandupperhalftrimmed.thumb.jpg.78ecb7aba1d3e5852928e47103ad9bb2.jpg

 

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10 hours ago, Andreas Preuss said:

 For the next alteration I trimmed the X shaped bass bar only in the upper half. When playing the instrument I noticed a sort of 'sizzle' in the sound which is usually  associated with very good instruments. All over the sound got more 'quality'. In short I am very happy about the last change.

Although a datapoint of one isn't proof, I'll use this as "I told ya so." :)

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Latest modifications:

1. Thin down the edges and slightly the lower half. The lower half was in some areas around 3.0mm which I thought is too thick in comparison to the 2.1-2.3 on the upper half.

I lowered as well the bass bar some fraction of a millimeter. After reducing the plate just 0.5g were missing to make the 5% weight reduction complete, so I 'cheated' by taking the weight from the bass bar.

This all resulted in a weight loss of c. 3g. The top with the X bass bar is now 58g and reached for me the limit what can be reduced in weight. 

I cleaned as well a bit the top linings

After assembling the instrument and (impatient as I am) when I played it just after I removed the clamps it sounded again hollow with an over resonance on G played on the D string. Intrestingly this somehow  disappeared when I played it the following morning. It seems that the structure must stretch in for at least a day. Now it sounds pretty crispy and has a good loudness. 

General data

weight 297g

string angle 160

Bridge height 30.5NCV50(2).thumb.jpg.b4aa78f2642d5acd846a74f2ede7a874.jpg

 

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  • 2 weeks later...

OK, yesterday I had a few minutes to take off the back remove the remains of the old linings and glue two new solid linings. I didn't expect too much of a change in the sound. However, it lost  bit of its previous interesting non usual quality. But this quality was paired with some uneveness in the loudness, some notes being more muted.

So now it lost a bit of that but became more even and is still pretty crispy. There is nothing which reminds of the previous woofiness except that the lower register is really full and sonorous. all this looks like an overall improvement. 

Same bridge as before

One thing I cant explain is that the violin became lighter despite added mass. 

Current weight is 287g.

No other changes.

1997497268_NCV52(1hourafterstringingupSPadjustment).thumb.jpg.cdf67a305da6a9f827451ca4618dfebe.jpg

 

and the same graph in higher resolution

 

168553843_NCV52(1hourafterstringingupSPadjustment)16384resolution.thumb.jpg.4f1dc0a08ab24c8e5b958aa988715f51.jpg

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  • 2 weeks later...
On 4/8/2018 at 7:37 PM, Don Noon said:

I think you'd run into trouble trying to bend a 16mm thick slab.  Or you'd have to have variable height ribs.

Actually, I bent quite a few tops, but the trick is to bend a ~6 mm slab. That was eons ago when I was following Ed Campbell’s ideas that are in book 4 of his Little Red Books.

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11 hours ago, Don Noon said:

Looks kinda like you took out the bass bar, or cut the ends off.

It’s a new top made with bent wood. Weight is the same as the previous top maybe a pinch lighter. I copied for sound comparison the x shaped bass bar with the same length of all legs. 

it’s a kinda of interesting.

the sound got more grit or texture. 
 

The total weight is now 286g, with no intention to make it lighter it got lighter.

string angle is set very flat at 162.5

bridge height is 30mm

I switched strings to dominant forte which seem to work better. 
 
the whole body is sensitive to added weight, so the sound feels different with or without shoulder rest. 
 

another thing I noticed is that a bit more or less pressure from the sound post makes quite a difference.

If anything is now to improved it is the response of the a string which is a bit hard to play. Would be interesting now to hear it in a hall.

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It appears that your B1+ frequency is well below 500 Hz, which is getting near viola territory.  That is why I thought you did something radical to the bass bar to reduce stiffness.  It is surprising that a bent top would make things more flexible, assuming that the idea of a bent top is to make it stiffer than a carved one.

There is an alternative interpretation of the response plot, however unlikely... that the 390Hz peak is an exceptionally strong CBR, the ~480 Hz peak is the B1-, and the B1+ is either not registering, or way up in the peaks near 700 Hz.  This would be a bunch of unlikely results, so I'll assume the first one (floppytop) is correct.

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On 10/4/2018 at 12:27 AM, Andreas Preuss said:

The asymmetric f hole design allows it to shift the string axis towards the players hand. This gives more room at the c bouts. On a regular Strad model I measured the distance from e string to lower treble side corner 85mm on the super light violin it is only 78mm.

image.jpeg

My maker grandfaher writes that a longer f-hole on the e-string side will make a softer (wetter) sounding e-string. He used to cut eyebrows above and below the right f-hole of that reason. He was constantly experimenting and he was a player as well. 

I suppose you have good ideas behind this concept. It probably makes the left bridge foot area a little more mobile. I haven't read the complete thread yet. 

Edited by Anders Buen
Trying to translate norwegian better to english
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On 5/31/2018 at 6:48 PM, Torbjörn Zethelius said:

I can imagine that a bent top would have less creep. You could even make a super thin two ply top. I wonder how that would work?

In my first article based on my master thesis work on vibration modes in violins we investiged a concept of violins made using thin laminated plates and a system for supporting the pressure and tensions. The inventor was Mikael Hagetrø from south Trøndelag (mid norway). An amateur maker and inventor. The maker made all his machines for the purpose. I think he patented the concept, as well as at least one earlier version.

The work I and the concert master from the Trondheim Symphony Orchestra: Sveinung Lillebjerka, was from 1993-94. Hagetrøs daughter later tried to run a business based on the idea. According to the late bass professor Knut Guettler, the violas did have a certain potential. They painted the flames on the back plates. 

My article for Stockholm Musical Acoustics Conference in 2003 on that work:
https://www.researchgate.net/publication/267848892_OPERATING_DEFLECTION_MODES_IN_FIVE_CONVENTIONAL_AND_TWO_UNCONVENTIONAL_VIOLINS

http://knutsacoustics.com/files/the-hagetro-violin.pdf

Edited by Anders Buen
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