Jump to content
Maestronet Forums

Plate recurve


Deo Lawson

Recommended Posts

Hello,

I'd like to gather some opinions about the area of negative curvature around the egdes of the plate arch.

Having been around many different fine violins at my school, I've noticed that a lot of the professors (who are also working performers in the classical sphere) play on instruments with a very strong recurve in the arch. Sometimes even to the extreme... it looks like the center of the plate is bulging out like a beer belly. Of course they play on very nice sounding instruments which were carefully selected to project in a hall.

In my builds so far I used a fine violin that I own as a reference. However, this violin does not have a very strong recurve, so neither do the instruments I made. None of my instruments approach the volume of those professional violins.

Now I know that I am focusing on a small sample size and a very specific characteristic, but somehow, intuitively I get the sense that the recurve is vital for increasing mmmph-age of a violin. I'm curious what professional makers think.

Link to comment
Share on other sites

3 hours ago, Davide Sora said:

I would say yes for upper and lower bouts, no for the C bout, and a lot depends on the thickness

2 hours ago, JacksonMaberry said:

I would agree strongly.

...and so now we have an arching characteristic correlated to a characteristic of the sound produced by a violin - Mr. Sora's concurrence somewhat reserved, but confident and conditional, Mr. Maberry's (hopefully spelled correctly this time) pretty much unequivocal. 

This should be testable with a series of properly designed experiments.  If verifiable it would be progress - such an effect could be amenable to a meaningful, if still perhaps difficult, analysis.

I don't recall however that the Cannon has recurve.  Although I unfortunately don't recall much other than the scroll and plate edge from the 1988 New York exhibition, but judging from both heresay and my experience at the exhibition, it is a very loud instrument.

(later) - I pulled out a booklet with Edward Neill's history and Candi's sketches.  There doesn't seem to be any recurve on the long axis certainly, and I don't see anything that I would call recurve on the table templates (I'm assuming the upper figure on p. 71, with 'della tavolarmonica' - but I have no Italian). - maybe the back...kinda sorta.

Link to comment
Share on other sites

6 hours ago, Dr. Mark said:

 There doesn't seem to be any recurve on the long axis certainly

I was mainly talking about transverse sections, longitudinally is a different matter. Too much recurve at upper and lower blocks in the top would decrease the structural strength due to compression, so better to avoid. The back is different, no compression there.

Just my opinion, but you will find many archings questioning it. C'est la vie.:rolleyes:

Link to comment
Share on other sites

11 hours ago, Dr. Mark said:

This should be testable with a series of properly designed experiments. 

I did a test some years ago and posted it on MN, but can't seem to hunt it down.

I used the same spruce, same arch height, same weight, and made two top plates:  one with zero recurve anywhere, and one with "normal" recurve (some in the upper and lower bouts, minimal in the long arch and C bout).  I used the same violin body to test them on, to eliminate back/ribs differences.

As I recall (questionably), there was not much difference that showed clearly on measurable spectra, but in playing, the one without recurve seemed a little "stiff", or lacking some low end.  Perhaps with different wood or different grads, the recurved plate would have too much low end, and the stiffer non-recurved plate would be preferable.

I look at as many good instruments as possible to see where the inflection points (from convex to concave) are located... and then I do that.  It seems to work pretty well.

Link to comment
Share on other sites

1 hour ago, Don Noon said:

there was not much difference that showed clearly on measurable spectra, but in playing, the one without recurve seemed a little "stiff", or lacking some low end

Food for thought...I don't have any experimental equipment but it wouldn't take too much and I could try to repeat your experiment.  I had a mic around somewhere, and since it's a relative measure the characteristics won't matter too much, but I need to figure out and set up some other things...

BTW I finally picked up the batteries for my laser with a q&d first look I could get about the first 20 cm or so of my plane sole illuminated at glancing incidence.  I need to revisit that, and what I said I was going to try to do with it lol.  Advanced age is such a kick!

Link to comment
Share on other sites

I have to agree with your findings, Don, that violins with no recurve feel stiff---in my fairly limited experience anyway. The professionally made violin that I own sounds good, but has always been a difficult player. Likewise my self made violins are not the most responsive, even after I've gone through and adjusted everything to the highest level I can (bar, post, bridge). As a player I feel that none of my instruments efficiently distribute the energy of my bow, and it reflects back into my hand.

I plan to make a new plate for one of my instruments, incorporating a much stronger recurve but keeping everything else the same. Maybe I'll report back to this thread when I finish that project.

Link to comment
Share on other sites

I'd like to avoid moving on to a 'stiffness' criterion until 'loudness' is played out, unless they're somehow synonymous.  Given that the consensus is true and recurve promotes loudness, it seems that there should be an increase in power/sound pressure somewhere in the spectrum, or a shift in the frequency of significant contributions to the power towards ~1.2 kHz.  That's why I think it might be verifiable/debunkable through testing.

Link to comment
Share on other sites

3 minutes ago, Dr. Mark said:

I'd like to avoid moving on to a 'stiffness' criterion until 'loudness' is played out, unless they're somehow synonymous.  Given that the consensus is true and recurve promotes loudness, it seems that there should be an increase in power/sound pressure somewhere in the spectrum, or a shift in the frequency of significant contributions to the power towards ~1.2 kHz.  That's why I think it might be verifiable/debunkable through testing.

I hadn't considered recurve being a loudness factor, but maybe so. My observation has been that plates which have a healthy recurve (within reason) in the upper an lower bouts while maintaining stiffness in the center bout, partially via shallower channels (and thereby greater thickness, at least when I make them), have a broader palette of available tone color and more nuanced bowing response. 

On my earliest instruments I extended the same recurve geometry from the upper and lower bouts across the upper and lower block areas, but got wise eventually and leave it shallower there now to maintain a stiffer central "ridge" from block to block. That did seem to give an increase in upper power limit. 

Link to comment
Share on other sites

On 9/15/2023 at 3:03 PM, Deo Lawson said:

Now I know that I am focusing on a small sample size and a very specific characteristic, but somehow, intuitively I get the sense that the recurve is vital for increasing mmmph-age of a violin. I'm curious what professional makers think.

 

1 hour ago, Don Noon said:

I was unaware of that consensus.

 

2 hours ago, JacksonMaberry said:

I hadn't considered recurve being a loudness factor, but maybe so

 

Sorry I thought it was clear what the topic was. So only Mr. Sora?  And Mr. Maberry as non-committed?

Link to comment
Share on other sites

30 minutes ago, Dr. Mark said:

Sorry I thought it was clear what the topic was. So only Mr. Sora?

I don't think I said that recurve necessarily increases loudness. Unless by "mmmph-age" you just meant loudness. By the way, what exactly is meant by "mmmph-age"??:rolleyes:

However, as always up to a certain point the loudness will also increase, but then it will start to decrease if you exaggerate with the recurve or with the thinning of the thicknesses in that area, and the sound may also become overly thin and too soft.

I'm sorry, but it is not possible to generalize or establish universal guidelines.

Link to comment
Share on other sites

On 9/15/2023 at 3:03 PM, Deo Lawson said:

None of my instruments approach the volume of those professional violins.

Now I know that I am focusing on a small sample size and a very specific characteristic, but somehow, intuitively I get the sense that the recurve is vital for increasing mmmph-age of a violin. I'm curious what professional makers think.

Once again it seems I need to apologize, this time for not including more of the original post where 'mmmph-age' seems to refer back to volume, which I equated with loudness.  Violinmakers are certainly a touchy bunch lol.  But perhaps I misunderstood Mr. Dawson's question - that would be the icing on the cake.  And Mr. Sora, I think my lack of knowledge of Italian is forcing you to express rather nuanced information in English, so I'm under the impression that I have no-one now who will say that they believe, ceteris paribus, that recurve is correlated with loudness.  Am I correct? 

Edited by Dr. Mark
Link to comment
Share on other sites

9 minutes ago, Dr. Mark said:

Once again it seems I need to apologize, this time for not including more of the original post where 'mmmph-age' seems to refer back to volume, which I equated with loudness.  Violinmakers are certainly a touchy bunch lol.  But perhaps I misunderstood Mr. Dawson's question - that would be the icing on the cake.

We may also be having some difficulty because my lack of knowledge of Italian is forcing Mr. Sora to express nuanced information in English.

For my part I missed the bit in the op about mmmph. But I'm barely literate, sorry. 

Link to comment
Share on other sites

I'm not a professional maker but I think I know something about arching which might put things into perspective.

In the photo I've drawn cross arches (in blue) using templates I have made.

With the lower bout one I've drawn an alternative one in red. The original line is behind it in pencil.

I've included the lower corner one to show how large the recurve needs to be because it extends so far out to the plate edge. I would not draw up any arching plan which changed that profile much at all.

With the waist I have made a template as wide as practical, leaving enough recurve for a scoop at that position. You could widen the recurve by flattening the top of the arch but you would end up distorting the smooth transition from convex to concave.

With the lower bout the negative length of the scoop or recurve is actually increased about 1 cm but the deviation of the arc is only about 2 mm. It shows how finely balanced the shape is. There is not so much room to manipulate the shape at the waist. You would have to distort things quite a bit.

I haven't shown the upper bout or corner because the same dynamics as the lower bout apply. So the recurve of the upper bout could be widened quite a bit whereas the upper corner could not.

 

DSC_0003.JPG

Link to comment
Share on other sites

4 hours ago, donbarzino said:
4 hours ago, JacksonMaberry said:

Marking that whole yellow area as recurve seems silly to me, personally.

I understand "recurve" as the concave zone around the edge, as opposed to the convex in most of the central area.  With that definition, the diagram is unlike any violin I have ever seen, or would want to see.  It's nonsense.

1 hour ago, Deo Lawson said:

"Mmph-age" is exactly what it sounds like. When you floor it, it goes.

For those who think recurve is needed for loudness, check out the Vieuxtemps Guarneri.  It's known for extreme loudness, and has less recurve than almost anything out there.

Link to comment
Share on other sites

The Vieuxtemps looks to me to have very full long arches front and back with little recurve as does the cross arching.

But I would say that the arching front and back is very low and that might account more for what it sounds like than anything else as well as the lack of recurve.

He was probably working with a thin wedge.

Link to comment
Share on other sites

9 hours ago, Dr. Mark said:

  And Mr. Sora, I think my lack of knowledge of Italian is forcing you to express rather nuanced information in English, so I'm under the impression that I have no-one now who will say that they believe, ceteris paribus, that recurve is correlated with loudness.  Am I correct? 

I don't rule out that the recurve could play a role in loudness, but I don't think you can use it as if it were a volume knob, something like "I move the inflection point to increase or decrease the loudness", it's definitely more complicated.

Link to comment
Share on other sites

9 hours ago, Don Noon said:

For those who think recurve is needed for loudness, check out the Vieuxtemps Guarneri.

We should probably differentiate between what is necessary for, and what is one path to achieving, a result.  I don't think anyone has gotten near postulating that recurve is necessary, but I understand your concern that some reader may have that conception.  This gets back to my example where increasing the power in some part of the spectrum, or shifting the frequency of some of the power peaks towards ~1.2 kHz could achieve the same result.  They would likely require different means to achieve.  Maybe one through flattening an arch and higher ribs, maybe the other by lowering the ribs and raising the arch (these aren't intended to be valid but just to illustrate the point)- or perhaps we prefer placing the violin beneath the portrait of Stradivari, lighting three candles, tracing the mystic signs, and reciting the words of power.  The sound of the bell marks completion of the spell.

9 hours ago, Don Noon said:

I understand "recurve" as the concave zone around the edge, as opposed to the convex in most of the central area.  With that definition, the diagram is unlike any violin I have ever seen, or would want to see.  It's nonsense.

Good point - Are we defining 'recurve' relative to the tangent at the inflection point, or relative to the horizontal, or...?  We should probably all be on the same page with regard to terminology.  I think 'scoop' has been used in the past in this forum, but I don't know if it's the same as recurve.

4 hours ago, Davide Sora said:

I don't rule out that the recurve could play a role in loudness, but I don't think you can use it as if it were a volume knob, something like "I move the inflection point to increase or decrease the loudness", it's definitely more complicated

Understood.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    • No registered users viewing this page.


×
×
  • Create New...