Dead sounding slab of maple. Should I use it?

[Claudio Rampini]

39 minutes ago, Marty Kasprzyk said:

I believe slab cut Bigleaf maple has a very unique and more interesting appearance than if it was quarter cut which looks more like millions or ordinary curly maple backs.

I agree, especially if you have a good oil varnish.

[Anders Buen]

Using a slab cut back may lead to a violin with low frequency for the B1+ mode and possibly a low frequency for the B1- as well. Maybe a bit mellower sounding. That is: you will probably get a violin that is a bit different sounding than a standard built one.

[Marty Kasprzyk]

12 hours ago, Anders Buen said:

Using a slab cut back may lead to a violin with low frequency for the B1+ mode and possibly a low frequency for the B1- as well. Maybe a bit mellower sounding. That is: you will probably get a violin that is a bit different sounding than a standard built one.

Hi Anders,

When you did your acoustic comparisons of lots of famous old Italian violins were there was any photos or information to show which ones were two piece backs vs. one piece backs?

 It would be interesting to compare their sound qualities.

[Don Noon]

Perhaps with a careful survey of many instruments, you might be able to observe some kind of trend.  Or perhaps not.  

In looking through my data quickly, one example stands out as rather interesting.  The back wood was not only cut at a high off-quarter angle, but the longitudinal grain was wavy and curved.  If you wanted good stiffness/weight, this is exactly what you would NOT want.  It looks kinda like bigleaf, but it's Euro.

Taptones ran on the low side, so I left it on the heavy side (for me).  Signature modes of the final instrument came out slightly lower than my normal, but only by a few Hz.  No biggie.

It won the top tone awards at the VMAAI competition, and sounds like this:  https://www.youtube.com/watch?v=FTZYM0NoWfs

So, who knows.  Stuff turns out different ways, hard to make useful predictions what something will sound like.  Mode frequency trends could well be semi-predictable, but I don't see that as a good indicator of what it relly SOUNDS like.

[Dr. Mark]

Nice Mr. Noon.  What did the violinist say about it?

[Anders Buen]

22 hours ago, Marty Kasprzyk said:

Hi Anders,

When you did your acoustic comparisons of lots of famous old Italian violins were there was any photos or information to show which ones were two piece backs vs. one piece backs?

 It would be interesting to compare their sound qualities.

There are photos of each in the Miracle Makers Book and some in other sources. Ill see what I can figure out.

[Claudio Rampini]

On 7/29/2024 at 1:10 PM, Marty Kasprzyk said:

Hi Anders,

When you did your acoustic comparisons of lots of famous old Italian violins were there was any photos or information to show which ones were two piece backs vs. one piece backs?

 It would be interesting to compare their sound qualities.

It's difficult to understand if the different tonal qualities are caused by a two or one piece backs, or one piece back cut on the slab in the old violins, the best thing is to test on your own instruments. I know that the poplar or the willow backs are producing a warmer tone on the violas and the cellos, but the maple is a stronger wood.

[Dr. Mark]

I tend to believe Mr. Noon.   He usually has measurements to back up his assertions, and tends not to express as fact an opinion that lacks supporting data.

[Marty Kasprzyk]

On 7/29/2024 at 7:10 AM, Marty Kasprzyk said:

Hi Anders,

When you did your acoustic comparisons of lots of famous old Italian violins were there was any photos or information to show which ones were two piece backs vs. one piece backs?

 It would be interesting to compare their sound qualities.

Quarter cut maple is used for one piece or two piece backs. 

Is it correct that slab or flat cut maple is always used for one piece backs and never used for two piece backs?

[Don Noon]

1 hour ago, Marty Kasprzyk said:

Is it correct that slab or flat cut maple is always used for one piece backs and never used for two piece backs?

I would never say never.  Although the common reason for a slab cut is to get the widest plank out of a modest sized tree, there is nothing preventing someone from cutting a narrower, thicker slab for a 2-piece back.  Maybe someone has run across such a thing.

In general, I see the maple supply as far more variable than spruce as far as quarter, slab, and everything inbetween... even in the same board.  I recall seeing a Sam Z. violin at VSA one year where I noted that the back cut was very near 45 degrees off-quarter (or off-slab, if you prefer).  It was fine, as you'd expect from Sam.

Given that wood varies from tree-to-tree in significant ways, it is my educated guess that, at best, you might find some reasonable correlation between cut angle, taptone, weight, and signature modes of the assembled instrument.  Maybe.  After a lot of effort.  If precise signature modes is your thing, then it might mean something to you.  It doesn't to me... and I don't see much hope of getting meaningful correlations to anything more than that.

[Anders Buen]

On 7/29/2024 at 1:10 PM, Marty Kasprzyk said:

Hi Anders,

When you did your acoustic comparisons of lots of famous old Italian violins were there was any photos or information to show which ones were two piece backs vs. one piece backs?

 It would be interesting to compare their sound qualities.

Are you able to see the "H" with pencil behind each instrument? H is "Hel", - whole back. Surprisingly many of them do have a whole back. I haven't figured out which are slab cut, though. Maybe the text on them can help?

Stiffness is also dependent on the thickness and arching, as you know. So to some extent weaker wood can be compensated with stiffer construction. "Tap tuning" could be one route to do so.

[Marty Kasprzyk]

1 hour ago, Anders Buen said:

Are you able to see the "H" with pencil behind each instrument? H is "Hel", - whole back. Surprisingly many of them do have a whole back. I haven't figured out which are slab cut, though. Maybe the text on them can help?

Stiffness is also dependent on the thickness and arching, as you know. So to some extent weaker wood can be compensated with stiffer construction. "Tap tuning" could be one route to do so.

Wow!  I didn't realize so many were made with one piece backs. Or maybe one piece backs sound better so more were included in the recordings.

[Don Noon]

6 hours ago, Marty Kasprzyk said:

Or maybe one piece backs sound better so more were included in the recordings.

I can think of no reason why a 1-piece back would sound any different from a 2-piece. 

However, the most spectacular-looking (IMO) backs are 1-piece, and good 1-piece backs are the most expensive.  So it is reasonable to assume that a maker would use those backs for their best efforts for high-level clients, and would end up being most prized and well cared for.

[Marty Kasprzyk]

9 hours ago, Don Noon said:

I can think of no reason why a 1-piece back would sound any different from a 2-piece. 

However, the most spectacular-looking (IMO) backs are 1-piece, and good 1-piece backs are the most expensive.  So it is reasonable to assume that a maker would use those backs for their best efforts for high-level clients, and would end up being most prized and well cared for.

It has been shown that the asymmetric positions of the sound post and bass bar increases the sound output from the top plate.

Perhaps one piece asymmetric grain back plate like yours with different elastic moduli on left and right sides might also be helpful.  The acoustic effect might be small but any improvement is beneficial.

 

[Don Noon]

2 hours ago, Marty Kasprzyk said:

Perhaps one piece asymmetric grain back plate like yours with different elastic moduli on left and right sides might also be helpful.  The acoustic effect might be small but any improvement is beneficial.

I would hesitate to use the terms "helpful" or "beneficial" regarding odd grain patterns in maple backs.  More like "very slightly different, at most"  is my thinking, and listeners/players may have varying opinions.  What the maker does with the weights and graduations and arching can push effects around to where it's going to be a mess to try to figure out cause and effect.  Not to mention that every piece of wood will be slightly different anyway.  I'll pass on this potential research project.

[Anders Buen]

On 7/30/2024 at 10:57 PM, Marty Kasprzyk said:

Wow!  I didn't realize so many were made with one piece backs. Or maybe one piece backs sound better so more were included in the recordings.

I found the spectrum data from the Miracle Makers Solo Sibelius bit on 15 Strads and 15 del Gesus and sent it to a statistics program. The first plot is the overall LA eq [dB], sort of loudness, versus the calculated Dünnwld L-Parameter, the level difference between the A0 and the highest peak in the midrange 630Hz to 1150 Hz or so.
 

The second plot is the sound level of the 1/12th octave frequency band where we may expect to find the A0 again plotted versus the Dünnwald L parameter. We see a slight correlation there, because they are linearly dependent.

It is difficult to see any clear difference between the one piece backs and the two piece ones. The three-six loudest ones are one piece, the weakest one is a two piece. The differences are rather small. The three lowest L parameter values comes from one piece instruments. One of them is the Hellier Strad, possiby a stiff-ish instrument.

[Marty Kasprzyk]

On 8/17/2024 at 2:24 PM, Anders Buen said:

I found the spectrum data from the Miracle Makers Solo Sibelius bit on 15 Strads and 15 del Gesus and sent it to a statistics program. The first plot is the overall LA eq [dB], sort of loudness, versus the calculated Dünnwld L-Parameter, the level difference between the A0 and the highest peak in the midrange 630Hz to 1150 Hz or so.
 

The second plot is the sound level of the 1/12th octave frequency band where we may expect to find the A0 again plotted versus the Dünnwald L parameter. We see a slight correlation there, because they are linearly dependent.

It is difficult to see any clear difference between the one piece backs and the two piece ones. The three-six loudest ones are one piece, the weakest one is a two piece. The differences are rather small. The three lowest L parameter values comes from one piece instruments. One of them is the Hellier Strad, possiby a stiff-ish instrument.

I was never a fan of Duennwald's comparison methods because he normallized all his violin frequency response curves: "The maximum response level in the 650 Hz-1120 Hz range is designated at 25 dB."  Thus a violin which has a weak ouput in this range is made artificially equivalent to one which has a strong output there.  I doubt listeners or players would judge them to be the same.

I think a better comparison would be to just compare the various average band levels of one piece backs with two piece backs like you've done in your other studies comparing Strads vs. DGs etc.  

Are one piece backs always slab cut or are they be quater cut if the tree was big enough?  

 

 

 

[JacksonMaberry]

19 minutes ago, Marty Kasprzyk said:

I was never a fan of Duennwald's comparison methods because he normallized all his violin frequency response curves: "The maximum response level in the 650 Hz-1120 Hz range is designated at 25 dB."  Thus a violin which has a weak ouput in this range is made artificially equivalent to one which has a strong output there.  I doubt listeners or players would judge them to be the same.

I think a better comparison would be to just compare the various average band levels of one piece backs with two piece backs like you've done in your other studies comparing Strads vs. DGs etc.  

Are one piece backs always slab cut or are they be quater cut if the tree was big enough?  

 

 

 

They're sometimes quartered

 

[David Burgess]

35 minutes ago, Marty Kasprzyk said:

Are one piece backs always slab cut or are they be quater cut if the tree was big enough?

All the one-piece backs I've used have been quartered.
On occasion, I used one half of a two-piece quartered cello back for a violin back.

[LCF]

24 minutes ago, David Burgess said:

All the one-piece backs I've used have been quartered.
On occasion, I used one half of a two-piece quartered cello back for a violin back.

Aha!

One Cello = 4 violins plus change 

[Marty Kasprzyk]

 

So we have a 2 by 2 matrix of combinations:

                        one piece   two piece

quartered:          yes              yes            

slab cut:            yes?             no?

There are some aestetic differences or maybe some or acoustic differences or preferences.  But my guess is that large old maple trees might have been rare hundreds of years ago in Europe so 2 piece backs from small young trees were often used https://en.wikipedia.org/wiki/History_of_Central_European_forests#:~:text=The consequences of medieval forest,remote forest areas were affected.

[Dr. Mark]

I have some riff-sawn lumber...

[Don Noon]

On 8/17/2024 at 11:24 AM, Anders Buen said:

It is difficult to see any clear difference between the one piece backs and the two piece ones. 

It is comforting to know that the measurements are in harmony with theory.

Perhaps if you could compare slab backs to quartered backs... with all other construction details identical... you might possibly see something.  There are too many sources of variability otherwise.  Or even samewise, since nothing is ever identical in this biz.

[Anders Buen]

2 hours ago, Don Noon said:

It is comforting to know that the measurements are in harmony with theory.

Perhaps if you could compare slab backs to quartered backs... with all other construction details identical... you might possibly see something.  There are too many sources of variability otherwise.  Or even samewise, since nothing is ever identical in this biz.

Hi! I may need some help from someone with a better eye than my own on figuring out which are slab cut or quartered. I can give it a try, but I may need some guidance. Eg will strong flames always go with quarter cut wood?

Edited August 19 by Anders Buen
Spelling correction

[dan gall]

On 7/30/2024 at 11:09 AM, Don Noon said:

...

In general, I see the maple supply as far more variable than spruce as far as quarter, slab, and everything inbetween... even in the same board.  I recall seeing a Sam Z. violin at VSA one year where I noted that the back cut was very near 45 degrees off-quarter (or off-slab, if you prefer).  It was fine, as you'd expect from Sam.

...

I've seen a lot of trees with some degree of spiral grain, especially on terrain with high winds, which also tends to produce the most/best tiger/quilted maple.  Sugar maples tend to be the most obvious among the hardwoods and some softwoods can grow in such a way that they look like a piece of spun taffy.

I expect that extracting perfectly quarterded wood from trees is not high on most mills' business goal priority lists, even if it were a reasonable technical goal, which I doubt.  The reduction of mill throughput / productivity alone would nix even the most elegant technical solution.  Not to mention having to then determine what market each spiral angle range a piece of wood could be sold to.  There are times when breaking abstractions is the right thing to do, but probably not here.

https://pubs.cif-ifc.org/doi/pdf/10.5558/tfc33335-4

https://www.conifers.org/topics/spiral_grain.php

 

 

Edited August 19 by dan gall