Andreas Preuss

Andreas Preuss Super-Light-Violin Project

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For those interested, my super light violin got featured in the Strad magazine in the September issue.

The article written by Peter Somerford highlights assymetric design violins. 

BTW when I posted some pictures of my design on FB, a violinist immediately replied 'That's ugly'. Now that I see my violin along with other designs, I think my approach is pretty conservative. However I think that most of the assymetric design instruments are pretty cool to look at. I couldn't say that any of the designs is really ugly but I am always wondering if a classic music artist would step out on a stage with some of them. 

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17 minutes ago, Andreas Preuss said:

For those interested, my super light violin got featured in the Strad magazine in the September issue.

The article written by Peter Somerford highlights assymetric design violins. 

BTW when I posted some pictures of my design on FB, a violinist immediately replied 'That's ugly'. Now that I see my violin along with other designs, I think my approach is pretty conservative. However I think that most of the assymetric design instruments are pretty cool to look at. I couldn't say that any of the designs is really ugly but I am always wondering if a classic music artist would step out on a stage with some of them. 

To be honest, I thought that your design was quite elegant. 

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54 minutes ago, Nick Allen said:

To be honest, I thought that your design was quite elegant. 

Oh thanks, Nick! 

At least I tried to incorporate some design principles of 18th century makers using circles. 

Being my own critic I think the bass side f hole became a little too long and too wide. But hey, really good design is a development process. My guideline (maybe because I am from Germany) is the design of the  Porsche sportscar. Now after over 70 years you still see the original idea despite it has gone through many many changes. I hope I can do this with my own design.

Hope that one day I can throw it on the market. Right now I still need to cure some 'child diseases'. 

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Now finally I got time to get back to my super light violin.

The first thought is of course 'If it doesn't sound when it is too light maybe adding weight in various locations will just make it sound.'

Because the top and back were both normal in weight and thicknessing etc. it was clear that the cause for the too woofy and boxy sound was either on the ribs or on the neck.

FIRST CHANGE made was on the neck. So just to know for sure I replaced the spruce neck with one of the most solid woods available and made it in Fernambuko. (Many thanks to @duane88 who generously send me a block of Fernambuko big  enough to make a neck graft.)

To make a long story short: The new neck didn't change anything in a significant degree when the instrument was played. With the new Fernambuko neck it still sounded woofy and boxy. 

The conclusion was that the ribs needed to be altered. Before I fooled around with crack clamps setting them over the top and/or back ssqueezing the body in W-O direction to hear if it has any effect. Though the weight of the clamps adds a considerable damping factor on the outcome it somehow seemed to improve the playability of the instrument in a way that the sound became a bt more focused with more 'body'. 

My hypothesis from there was that the overtone range is somehow related to to the cross stiffness of the entire violin body and any reinforcement on the ribs which stiffens the O-W motion of the rib garland should improve the sound. 

SECOND CHANGE was to replace the tiny linings (c.1.5mm x 4.0mm triangular shape) with solid linings (2.0mm x 8.0mm) to stiffen the rib garland. the change was only made on top side. The tonal result was judged as positive. Though the woofiness and boxiness was not completely gone the sound had gained much in body and clarity especially on the G and D string.

THIRD CHANGE was to double the linings to give the rib garland on the top side even more stiffness. This change was judged as positive again and actually the sound had improved to a degree that I wouldn't hesitate to show it a professional musician. But still I was wondering if the sound couldn't be improved further.

FOURTH CHANGE was to lower the string angle, because the remaining woofiness and boxness was atttributed to the rather steep neck angle and too high bridge (35mm). So I removed the fingerbooard and planed the surface towards the neck heel to lower the neck angle. The bridge height ended at 32mm and the alteration was judged as positive because the boxiness on the G and D string was again diminished. (But still not completeley gone.)

After that I made a few minor changes with the soundpost position and the bridge thickness which resulted in the graph below. 

SUMMARY

The ribs have an enormous inflence on the sound and it seems that the the frame built to the top have a significant effect on the sound. However, the rib thickness on the super light violin is only 0.4 with the japan paper reinforcement and it seems that the the thinner the ribs the more crucial becomes the thickness of the linings especially on the the top side. It confirms my hypothesis that the top should have a very stiff frame to support the low cross stiffness in order to produce a broad over tone range. (I don't have a scientific explanation for that.)

I will post more detailed information later. 

For the moment just the two sound graphs before all alterations and after (as it is right now) On Don Noons recommendation i took the graphs by playing a half note scale starting from G to B on the E string.

image.jpeg

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Addition:

The weight in its current state is with the super heavy neck 330g (without chinrest).

Next planned alteration is to put back a light neck made from light willow (0.37g cm2) whichi will reinforce inside with a 2mm plywood. Expected weight loss is 17g and shouldn't affect the overall sound characteristics.

 

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10 hours ago, Andreas Preuss said:

Expected weight loss is 17g and shouldn't affect the overall sound characteristics.

I agree with Jim. Thank you Andreas for sharing. Please keep us informed about future results. I would also be interested in how the experts here interpret the change in the FFT spectra before -> after.

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FIRST CHANGE

Picture of the fernambuko neck 

Just visually I thought a fernambuko neck would be pretty cool. It's really a pity that it doesn't alter the sound. I'll probably remove it without destroying it and keep it as a kind of memory.

 

image.jpeg

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SECOND CHANGE

First picture shows a bit of fooling around with the interior rib structure. First I glued a second 0.3mm maple veneer on the inside and then to diminish the inner air volume some corrugated card board. 

For the maple veneer doubling most changes were noticed when they were only glued on the C ribs inside. Result was a slightly diminished woofiness and boxiness. When I glued in the next step the veneer on the upper and lower bouts the result was disappointing: basically no audible changes. 

When the corrugated was glued all along the whole length of the ribs on both sides it was too much reduction in the air volume. The sound became thin like a fractional size violin. Therefore most of it was removed. Thereafter the sound was better but with the main problems remaining Woofy and Boxy. (Picture 1-2)

So I fetched my scalpel for the next major operation. I removed the cardboard, the veneer doublings cut the old linings out and cut back the vertical lining pillars so that I could install a solid 8mm wide lining.

(Just realized that I forgot to take a picture of that. :wacko:)

 

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THIRD CHANGE

Doubling the linings.

This diminished 80% of the biggest problems of this fiddle.

The top needs to Ben framed.  And apparently the back go along with tiny flimsy linings. 

Below the picture with the massive  linings.

 

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The general picture (from the graphs) is that the original condition had excessive response at the very lowest frequncies, way out of balance for what you normally want on a violin.  Having plates attached to each other with wimpy noodle ribs is likely the cause, with a tall bridge adding to the imbalance.

I am still not quite sure where the B1+ resonance is on this fiddle... either it's the weak nub at ~500 Hz, or maybe the stronger one ~580 Hz.  But for sure the CBR/B1- mountian still dominates (at this resolution, the CBR and B1- resonances moosh together in one bigger bump).

With the weak ribs and light balsa cornerblocks, I would expect the CBR to be the most wolfy and annoying problem, probably F or F# on the D string.  It might not be very loud, but it might be difficult to play cleanly there.

On a related but opposite note, on a violin I built not too long ago, I used ribs as thick as I could bend.  In my case, with torrefied high-density maple, it was ~1.2mm thick.  While the result may not have been totally due to the rib thickness, there just seemed to be a slight overly stiff feel to it, even after a couple of regraduations to loosen it up.

On an even more distantly related note, my last viola (40 cm) came in at 458g without chinrest, but with rosewood pegs and tailpiece.

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5 hours ago, Andreas Preuss said:

FIRST CHANGE

Picture of the fernambuko neck 

Just visually I thought a fernambuko neck would be pretty cool. It's really a pity that it doesn't alter the sound. I'll probably remove it without destroying it and keep it as a kind of memory.

 

image.jpeg

Beautiful work. Sorry it didn't sound as hoped.

Maybe I'll be able to visit yo next year...

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8 hours ago, Don Noon said:

The general picture (from the graphs) is that the original condition had excessive response at the very lowest frequncies, way out of balance for what you normally want on a violin.  Having plates attached to each other with wimpy noodle ribs is likely the cause, with a tall bridge adding to the imbalance.

I am still not quite sure where the B1+ resonance is on this fiddle... either it's the weak nub at ~500 Hz, or maybe the stronger one ~580 Hz.  But for sure the CBR/B1- mountian still dominates (at this resolution, the CBR and B1- resonances moosh together in one bigger bump).

With the weak ribs and light balsa cornerblocks, I would expect the CBR to be the most wolfy and annoying problem, probably F or F# on the D string.  It might not be very loud, but it might be difficult to play cleanly there.

On a related but opposite note, on a violin I built not too long ago, I used ribs as thick as I could bend.  In my case, with torrefied high-density maple, it was ~1.2mm thick.  While the result may not have been totally due to the rib thickness, there just seemed to be a slight overly stiff feel to it, even after a couple of regraduations to loosen it up.

On an even more distantly related note, my last viola (40 cm) came in at 458g without chinrest, but with rosewood pegs and tailpiece.

Thanks for your scientific comment. 

With my little experience in reading graphs I had a similar interpretation. In the first graph the  region between 200and 500 Hz is what represents the over resonance in low frequencies. In this state it was literally unplayable. 

Right now it has actually a bit unusual sound in the lower register but at the same time quite interesting with a bit gritty rough impression under the ear, something many professionals love to hear. With the next neck I am planning to lower once more the string angle and hope to lower the overall resonance between 200 and 500 HZ once more. But in the end I rely more on what I hear and how the instrument feels under the  bow. 

When all parts are too light it is a kind of fun fooling around with magnets to place weights in different spots and see how the sound changes. In case of the corner blocks I found that placing weights (I used 2g) on the diagonal opposite corners treble upper left and bass Lower right produces a sort of change in the feel for the player but nothing you would notice on the audacity graph.

For your side note: I think that weight is much more important in violas than on violins. When I finished the super light violin and it sounded too low I thought : I should have done that with a viola. 

 

 

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12 hours ago, Don Noon said:

With the weak ribs and light balsa cornerblocks, I would expect the CBR to be the most wolfy and annoying problem, probably F or F# on the D string.  It might not be very loud, but it might be difficult to play cleanly there.

When playing it I found this region more or less ok. Maybe there is a sort of over resonance on Gsharp. Sound sample attached playing the D string in half note scale with normal bowing followed by light bowing.

Edited by Andreas Preuss
Attach audio file

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9 hours ago, Andreas Preuss said:

When playing it I found this region more or less ok. Maybe there is a sort of over resonance on Gsharp.

I made my comments about the CBR before seeing the modifications you made to the ribs.  In the current condition, the audio clips indicate that not much is happening with the CBR.  I suspect it might have been a lot worse in the initial lightweight condition.  As it is now, it looks like you do have a very strong (excessive?) B1- resonance.

I am not too sure that the experience with the lightweight violin sounding like a viola would be directly applicable to a real viola.  In general I agree that relatively light construction and taller bridges tend to work better on larger-bodied instruments, but I also think that each type of instrument needs a more careful balance of all of the part stiffnesses and masses... which would also be a personal preference depending on the player.

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Next quick experiment on this violin:

The Bayon Bass Bar

before there was a traditional bass bar installed which was more tapered from bottom to top than usual making it more triangular in cross section. (To save one gram or so.) The first bass bar was c.4g.

The reason to install the Bayon Bass bar was to add weight to the top under the bass side foot of the bridge hoping the strong resonance between G and G sharp will diminish. The weight of the Bayon Bass Bar is c. 7g.

Result a bit later because just to my hearing the violin needs a day to settle in and readjust to string tension. 

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12 hours ago, christian bayon said:

Curious of your feeling after to try it!

You made it with the V profile? around 3.7mm at the gluing point under the bridge?

I followed the dimensions you gave me a while ago and it is pretty narrow under the bridge. (Though I didn't measure it)

Well, one has to keep in mind that the low resonances of this experimental violin were from the beginning too strong.

Playing the violin it didn't change in the direction I was hoping it would change to.  My hope was that a longer and  heavier bass bar would somehow give a better 'control' on those low frequencies.

Anyway, the changes were a kind of difficult to measure by ear. If I noticed anything there was rather a shift in the tone quality from a bit rough and rasp to a more round and mellow timbre. From my experience this usually goes along with additional dampening which I couldn't notice by ear. 

My first reaction was to switch the bar to the previous bass bar, but right now I decided to leave it and rather look on the neck material and angle again.

 

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