Can a flat topped/bottomed violin be made to sound like a regular arched violin?

[Aston4]

I'm starting to consider making my first violin body. Of course the arching is intimidating to me.

Does the arching actually add enough to the sound to be one of the main factors making a violin sound like a violin?

Yes I'm aware of vielles and the like, and how they sound, but I don't know how much of the sound difference is in the shape vs other stuff, e.g., soundpost.

I listened to the example of a... differently shaped viola here a few days ago, and it more or less had viola sound, at least through speakers. I've also found youtube demo's of fiddles made from foam, plastic, etc, that sound more or less like normalish violins.

I guess my question really is, can a "great" sounding violin me made, in violin shape, but without arching, just flat pieces of wood top and bottom? Surely many must have tried at some point.

 

 

[Dwight Brown]

I would think it would need a bracing system inside to resist the tension of the strings. I should imagine that it’s been done. I’m not a luthier or anything really and I do enjoy the strange and unusual. I have two cornerless instruments, a violin and a viola. I know I have seen plans for something along those lines.

DLB

[Dr. Mark]

Great sound for what music?  There are all kinds of examples out there to browse, e.g.

https://www.youtube.com/watch?v=qrmn7Cxof0k

and ...

https://www.youtube.com/watch?v=IkDq6bpgHic

 

[Aston4]

2 hours ago, Dr. Mark said:

Great sound for what music?  There are all kinds of examples out there to browse, e.g.

https://www.youtube.com/watch?v=qrmn7Cxof0k

and ...

https://www.youtube.com/watch?v=IkDq6bpgHic

 

They both sound like vielles.

[LCF]

Have you been face to face (ear to ear) with a gurdy? It's just a box with strings on and a keyboard and some buzzy bits.

[FiddleDoug]

I expect that Marty Kasprzyk might have some good information onthis subject. He's done a lot of work building things like that.

[Aston4]

10 hours ago, LCF said:

Have you been face to face (ear to ear) with a gurdy? It's just a box with strings on and a keyboard and some buzzy bits.

In 2001.  Once.  Just before the Gurdy player met the untimely end (as gurdy players often do) I have never heard a real gurdy since.

I wish I could remember exactly what it was like. I was entranced.

[Don Noon]

16 hours ago, Aston4 said:

I'm starting to consider making my first violin body. 

...

I guess my question really is, can a "great" sounding violin me made, in violin shape, but without arching, just flat pieces of wood top and bottom? Surely many must have tried at some point.

The first violin I made was with flat top and back.  One practical issue is that the waist needs to be much narrower than normal to allow for bow clearance... unless you want to make a bridge that's twice as tall as normal (good luck with that).  Ribs also need to be taller to get the internal volume up.

I made the plates on the thick side to get some stiffness out of the flat plates, but use the normal single bass bar and soundpost.

Shockingly, the signature modes ended up in about the normal spot.  However, the power distribution of all of the other frequencies was not normal.  Excessive power through the 700-1500 Hz range made it sound crude and boxy.

Perhaps if you work at it long enough, with reinforcements, balsa, carbon fiber, etc, maybe a great sounding flat-plate violin can be made.  As a first instrument, no way.  I'm sure you could make a better sounding violin using normal construction, even if it's a bit rough.  After this flat-plate "snakefiddle", I made a normal arched one, and it sounded infinitely more like a violin.

I doubt any violinist would appreciate being told that their violin sounds like a hurdy-gurdy.  Even a great hurdy-gurdy.  They are just different instruments.

[Marty Kasprzyk]

2 hours ago, FiddleDoug said:

I expect that Marty Kasprzyk might have some good information onthis subject. He's done a lot of work building things like that.

The top plate's longitudinal arch shape can be concave, flat, or convex, and its cross arch shape can also be concave, straight or convex which gives 9 possible combinations of top plate shapes.  Likewise for the back plate so the total number of arch shape combinations is 9*9 or 81 possible different shapes.

As an example a traditional violin uses convex longitudinal on convex cross arches for both the top plate and back plate. Some bass instruments have top plates convex longitudinal and cross arches but with backs having straight longitudinal and cross arch shapes.

Some combinations using top plate's with a concave longitudinal arch wouldn't be very good for resisting string tension so this reduces the number of combinations to just 54. 

About twenty years ago I had intended to go through all of these to see which worked best and attached are photos of two instruments that had straight longitudinal arches for both the top and back plates.  Both have convex cross arches for the top plate but one has concave cross arch for the back and one has a convex arch.

I believed at the time these shapes would give the very best resistance to deformations from string tensions common with traditionally shaped instruments.

These two worked fine and sounded ok which made me wonder which of the 54 combinations might sound best so I had intended to make all 54 combinations for entertainment. But  I was very methodical and started with the very simplest one first--straight longitudinal and cross arches for the top and back plates--flat tops and flat backs.

This one sounded pretty good too and I made the next thirty violins and viola with flat tops and played with various back plate arches, and never got to making all the other combinations.

I eventually concluded three things--any shape works,  I'm easy to please, and l have poor hearing.

IMG_0342 PDF.pdf

[Aston4]

30 minutes ago, Marty Kasprzyk said:

The top plate's longitudinal arch shape can be concave, flat, or convex, and its cross arch shape can also be concave, straight or convex which gives 9 possible combinations of top plate shapes.  Likewise for the back plate so the total number of arch shape combinations is 9*9 or 81 possible different shapes.

As an example a traditional violin uses convex longitudinal on convex cross arches for both the top plate and back plate. Some bass instruments have top plates convex longitudinal and cross arches but with backs having straight longitudinal and cross arch shapes.

Some combinations using top plate's with a concave longitudinal arch wouldn't be very good for resisting string tension so this reduces the number of combinations to just 54. 

About twenty years ago I had intended to go through all of these to see which worked best and attached are photos of two instruments that had straight longitudinal arches for both the top and back plates.  Both have convex cross arches for the top plate but one has concave cross arch for the back and one has a convex arch.

I believed at the time these shapes would give the very best resistance to deformations from string tensions common with traditionally shaped instruments.

These two worked fine and sounded ok which made me wonder which of the 54 combinations might sound best so I had intended to make all 54 combinations for entertainment. But  I was very methodical and started with the very simplest one first--straight longitudinal and cross arches for the top and back plates--flat tops and flat backs.

This one sounded pretty good too and I made the next thirty violins and viola with flat tops and played with various back plate arches, and never got to making all the other combinations.

I eventually concluded three things--any shape works,  I'm easy to please, and l have poor hearing.

IMG_0342 PDF.pdf 86.44 kB · 2 downloads

Wow.  It is going to take me a while to digest those shapes.  Legend.

[Dwight Brown]

I sort of like those Marty!

DLB

[La Folia]

On 5/16/2024 at 1:07 PM, Marty Kasprzyk said:

I eventually concluded three things--any shape works,  I'm easy to please, and l have poor hearing.

IMG_0342 PDF.pdf 86.44 kB · 7 downloads

They are pretty, though, aren't they?

[Aston4]

2 hours ago, La Folia said:

They are pretty, though, aren't they?

Looks like a 1500s painting.

[JacksonMaberry]

On 5/15/2024 at 3:27 PM, Aston4 said:

Does the arching actually add enough to the sound to be one of the main factors making a violin sound like a violin?

Yes. In my view/experience and that of the colleagues I admire most, it's generally ranked as the second or third most critical element to the sound character and performance characteristics of an instrument, after physical qualities of the material and alongside graduations.

Bad arch = lousy fiddle. 

What makes a bad arch? Any arch on any instrument that doesn't sound good/play well.

What defines "sounds good/plays well"?

This forum has never managed to agree on that one. 

[Dr. Mark]

On 5/16/2024 at 2:47 AM, Aston4 said:

They both sound like vielles.

Those were examples, meaning there are plenty more to listen to.  If you find one that meets your criteria then you've answered your own question.

[Don Noon]

Almost all tweeters are dome shaped for a reason.  That same reason affects the acoustics of any curved vibrating surface.  You can't play music on a saw if it's not curved, and especially not if it's a Sawzall.  Playing music with a Sawzall doesn't count.

[David Burgess]

33 minutes ago, Don Noon said:

You can't play music on a saw if it's not curved, and especially not if it's a Sawzall.  Playing music with a Sawzall doesn't count.

Grrrr....

[Dr. Mark]

3 hours ago, Don Noon said:

Almost all tweeters are dome shaped for a reason.  That same reason affects the acoustics of any curved vibrating surface.  You can't play music on a saw if it's not curved, and especially not if it's a Sawzall.  Playing music with a Sawzall doesn't count.

 

Analogies always make me a little suspicious, e.g. I think the important thing for high frequency sound production may be somewhat related to the mean stress in the vibrating material, with shape affecting the sound dispersion pattern.  A sawblade under tension, for example, would not need to have a curved mean shape to produce a tone although control by varying the stress would have to be done differently and maybe need a machine.  I think also a flat plate tweeter, possibly mounted with a built-in radial stress, could be made to work just fine. 

A flat plate violin is still subject to the stresses from the strings, with some differences relative to normal construction.  Relating the differences to sound quality particularly in any detail, and determining whether some construction method can produce a good flat plate fiddle, are challenges that I'm not up to at present. 

'Winslow Burhoe invented the inverted dome tweeter (see Photo 1). In this design, the dome is suspended at its edge but driven by a smaller diameter voice coil (see Photo 2). Regular dome tweeters are suspended at the edge and have the voice coil attached at the edge.  Burhoe introduced the inverted dome tweeter when he launched Epicure (also known as EPI) in 1970. Epicure designed and sold many successful designs. In the 1990s it became one of the Harman brands'.

Not much seems to be certain in this world IMO...

[Don Noon]

1 hour ago, Dr. Mark said:

Not much seems to be certain in this world IMO...

Fundamental physics is fairly well established.

For a flat beam with fixed ends, the natural frequency is determined by the speed of sound, length, and thickness (bending stiffness related).

For a bowed beam, at some point the "ring mode" takes over, where the natural frequency is only determined by the speed of sound in the material and the radius of curvature... thickness doesn't matter, as bending stiffness is not involved.

The latter consideration is why tweeters are domed (or dished), and very thin.

[Dr. Mark]

2 hours ago, Don Noon said:

Fundamental physics is fairly well established.

Certainly in local spacetime, at least close enough for government work.  We use Newtonian mechanics, but his absolute time, flat spacetime, particle nature of light, and a few other things are, well, there it is.

2 hours ago, Don Noon said:

For a flat beam with fixed ends, the natural frequency is determined by the speed of sound, length, and thickness (bending stiffness related).

re a beam, this is all I'm driving at - https://sci.bban.top/pdf/10.1016/0022-460x%2890%2990663-k.pdf  (discussion section):

'... As expected, a tensile [or compressive] force has the effect of increasing the motion
frequency'

[Anders Buen]

Probably not. The lows will be stronger than normal (given the same graduations) and the highs may not develop as well as on an arched violin. One major problem may be the worse behavior during humidity cycling than an arched instrument that may follow the variations easuer without cracking.

Hermann Mayer made a flat topped trapezodial violin as well as normal ones with high and low arching and documented them acoustically. His german PhD article was translated and republished quite recently in the VSA Papers.

[Anders Buen]

Probably not. The lows will be stronger than normal (given the same graduations) and the highs may not develop as well as on an arched violin. One major problem may be the worse behavior during humidity cycling than an arched instrument that may follow the variations easuer without cracking.

Hermann Mayer made a flat topped trapezodial violin as well as normal ones with high and low arching and documented them acoustically. His german PhD article was translated and republished quite recently in the VSA Papers.

Link to paper: 

Edited May 19 by Anders Buen
Added link and a figure.

[Don Noon]

1 hour ago, Dr. Mark said:

'... As expected, a tensile [or compressive] force has the effect of increasing the motion
frequency'

"As expected, a tensile force has the effect of increasing the motion frequency." Is the proper quote.  Compressive force LOWERS the frequency.  These effects are true only FOR A STRAIGHT BEAM.

Curved beams (or arched shells) do not behave this way; static forces have no first-order effect on the natural frequency of the structure.  With the caveat that carved tops might be a mix of curved and straight beam effects, depending on what frequency and mode shape you're looking at.

It's complicated.

[Dr. Mark]

51 minutes ago, Don Noon said:

"As expected, a tensile force has the effect of increasing the motion frequency."

The [ ] within a quote indicates a note by the individual using the quote.

59 minutes ago, Don Noon said:

Compressive force LOWERS the frequency.

Yes, my bad.  omega-bar would = root (1 - U) in that case.  I was thinking of the stresses in your saw example and didn't attend closely.  And I'm certainly not going to get too concerned about an example that we both seem to agree doesn't really apply except through analogy...

1 hour ago, Don Noon said:

Curved beams (or arched shells) do not behave this way; static forces have no first-order effect on the natural frequency of the structure.

Yes, but I understand the utility of simple examples to illustrate more complex concepts as well.

1 hour ago, Don Noon said:

These effects are true only FOR A STRAIGHT BEAM

I thought that was your example:

5 hours ago, Don Noon said:

For a flat beam with fixed ends, the natural frequency is determined by the speed of sound, length, and thickness (bending stiffness related).

Yes, yes - it says we must not hint, in print.  Not to worry - let's move on.  Complicated things often become easy when reduced to simple steps, but we're still lacking a definition of tonal quality, which makes 'look around' seem to be the only suitable answer to the OP's original question.

[Don Noon]

4 hours ago, Dr. Mark said:

... but we're still lacking a definition of tonal quality, which makes 'look around' seem to be the only suitable answer to the OP's original question.

There can never be any absolute definition of tonal quality, since it is subjective and listenerplayer dependent.

As for an answer to the OP's original question, that too is impossible to answer for sure, due to the same basic reason.  However, I think there are some significant physics and acoustics differences between flat and arched soundboards, and if you define a "great" sounding violin as an existing arched violin, and need to match that with a flat plate version, these fundamental differences might make the task very difficult or even impossible to achieve.

Or you could just make a flat plate violin and say it sounds great.  Nobody could prove you wrong.