Tap tone test , top plate

[Arsalan]

Hi everyone 

Please listen to , Below a recording of two different piece of tonewood with same dimensions but one fine grain and one regular grain ... 

would anyone be able to tell which one is better quality by hearing the taptone ? 
Also if anyone can give some guidance on how to compare tap-tone and how it should be like ? 
thank you 

[Davide Sora]

If the two pieces are actually of the same size and shape (they must be in order to compare them), the second (higher) tone indicates a stiffer wood, therefore probably a more performing wood than the first with the same geometry and dimensions. This data should at least be associated with the density and weight of the logs to have additional indications to be evaluated, listening to a recorded tap tone is not enough, the only thing you can actually evaluate is the difference in pitch, you can't get much information about the quality and feel the tap tone gives when listened live with the board between your fingers

[violins88]

So-called quality factor is speed of sound divided divided by density 

Higher number is better.

[Strad O Various Jr.]

Some wood just rings a lot better than other wood, that's just a fact, no matter what all the naysayers say!!

[Michael Darnton]

It's wood not a bell.

Unless you happen to be making a bell.

It's a bad habit to assume that more of anything is better, just because. Still looking for actual proof that wood that rings makes better violins. Making good violins from ringing wood does not prove that violins from non-ringing wood would be worse.

[Don Noon]

3 hours ago, violins88 said:

So-called quality factor is speed of sound divided divided by density 

Higher number is better.

3 hours ago, Strad O Various Jr. said:

Some wood just rings a lot better than other wood, that's just a fact, no matter what all the naysayers say!!

There are several different measurements that define the properties of wood, and different makers will focus on different properties to decide for themselves what they think is important.

If the wood pieces are exactly the same dimensions, then the second piece would have a higher speed of sound divided by density... sometimes referred to as "radiation ratio" (RR) or "quality factor"... although "quality factor" can also mean RR divided by damping.  A higher RR is not always better, although abnormally low RR I think would tend to be relatively quiet.

As mentioned, "quality factor" can also mean RR/damping, where low damping means a longer "ring".  In looking at an Audacity plot of the tap recordings, the peak amplitudes are not much different, but the second piece appears to ring longer, as evidenced by the fatter plot as the taptone decays to zero.  (The peaks are cropped off in the plot, to focus on the decay)

So, if I wanted a louder violin, I'd opt for the second piece, although what you end up with is hugely dependent on what you do with it.

[Don Noon]

26 minutes ago, Michael Darnton said:

Still looking for actual proof that wood that rings makes better violins.

That is impossible, until you can find actual proof of one group of violins is better than another.

However, I have enough experience (with my own results as well as from other makers) that violins made with wood with high RR and low damping tend to be more acoustically lively off-the-bench compared to other new wood.  Opinion, not proof.  And whether that's "better" or not is another layer of opinion, even less provable.

[Marty Kasprzyk]

3 hours ago, Strad O Various Jr. said:

Some wood just rings a lot better than other wood, that's just a fact, no matter what all the naysayers say!!

Thin sheets of aluminum with ribs should be much better than wood with if you want a high radiation ratio c/p and low damping.

[Michael Darnton]

Thanks, Marty.

I am reminded of a supposed Heifetz quote regarding ring, approximately: "I want my violin to sound when *I* play it. [not otherwise]"

[Don Noon]

4 minutes ago, Marty Kasprzyk said:

Thin sheets of aluminum with ribs should be much better than wood with if you want a high radiation ratio c/p and low damping.

Unfortunately, running the numbers ends up with ridiculously thin aluminum, as it is ~7X as dense as good spruce.  Wood is hard to beat.

[Michael_Molnar]

So what physical property differentiates (distinguishes) wood? Is it velocity dispersion?

[Don Noon]

16 minutes ago, Michael_Molnar said:

So what physical property differentiates (distinguishes) wood? Is it velocity dispersion?

There are a dozen or so properties that define a sample of wood... infinite if you want to consider that damping can be fequency-dependent.

These properties can be combined into seemingly important factors, like Radiation Ratio, or others.

As to what matters for a violin, and in what way, I have my opinions.  Others have their opinions.  There is no convincing quantitative formula for better or worse... except perhaps in abnormal extremes.  I'm certain a cast lead violin would not work satisfactorally.

[Strad O Various Jr.]

As the antique violin maker had no scientific testing equipment you can rest assured if they relied on anything, it was tapping on the wood, we were still being taught that when i was apprenticing in the 80s

[Marty Kasprzyk]

3 hours ago, Don Noon said:

Unfortunately, running the numbers ends up with ridiculously thin aluminum, as it is ~7X as dense as good spruce.  Wood is hard to beat.

So why aren't beer cans made out of wood?

[Michael_Molnar]

18 minutes ago, Marty Kasprzyk said:

So why aren't beer cans made out of wood?

The old masters brewed their beer in wood kegs, IIRC.

[Don Noon]

25 minutes ago, Marty Kasprzyk said:

So why aren't beer cans made out of wood?

Some slightly different requirements.  Aircraft carriers aren't made of wood, either.

[Advocatus Diaboli]

Not to play devils advocate too hard, but why not just cut a couple small cubes off each one and take a bite?  The crunchy wood could be better?

[HoGo]

I think it is completely silly/crazy idea to judge the wood just by listening to recording of being tapped.

Just very slight difference in size of the pieces will result into different tones as will even very slight difference n holding and tapping position. These two sound quite far apart in pitch so either the pieces are VERY different in stiffness/density/etc. or they are not exacty same to start with.

I've made several very succesful instruments out of wood rejected by other folks - theorists because of "not suitable tap tones" or similar crap.

I see that you finished your first violin so I'd suggest to concentrate on building techniques and mastery of tools and workmanship for the next few at least before bothering with esotheric wood selection processes and similar distractions - that will just slow down your progress. Just sharpen your gouges and planes and make some shavings.

[Wood Butcher]

13 hours ago, Marty Kasprzyk said:

So why aren't beer cans made out of wood?

 

13 hours ago, Michael_Molnar said:

The old masters brewed their beer in wood kegs, IIRC.

Just imagine the chaos when woodworm and woodpeckers got into the brewery 

[jezzupe]

Well about such things, Sherlock Holmes's recollection of Gustav Flaubert's words to George Sand "L’homme c’est rien–l’oeuvre c’est tout" the man is nothing, the work is everything, or in this case "le bois n'est rien, le violon est tout" the wood is nothing, the violin is everything, and or, the best piece of wood shall always be a "piece of wood" it's only when someone who is dedicated to the minutia of the entirety of the whole build from start to finish, and then has the further skills to develop any form of clientele, will it matter at all what piece of wood is chosen, and then when it is chosen, the "tap tone" is but one star in a galaxy of information and criteria when making a choice about such things....next question.

[Arsalan]

21 hours ago, Don Noon said:

There are several different measurements that define the properties of wood, and different makers will focus on different properties to decide for themselves what they think is important.

If the wood pieces are exactly the same dimensions, then the second piece would have a higher speed of sound divided by density... sometimes referred to as "radiation ratio" (RR) or "quality factor"... although "quality factor" can also mean RR divided by damping.  A higher RR is not always better, although abnormally low RR I think would tend to be relatively quiet.

As mentioned, "quality factor" can also mean RR/damping, where low damping means a longer "ring".  In looking at an Audacity plot of the tap recordings, the peak amplitudes are not much different, but the second piece appears to ring longer, as evidenced by the fatter plot as the taptone decays to zero.  (The peaks are cropped off in the plot, to focus on the decay)

So, if I wanted a louder violin, I'd opt for the second piece, although what you end up with is hugely dependent on what you do with it.

 

21 hours ago, Don Noon said:

There are several different measurements that define the properties of wood, and different makers will focus on different properties to decide for themselves what they think is important.

If the wood pieces are exactly the same dimensions, then the second piece would have a higher speed of sound divided by density... sometimes referred to as "radiation ratio" (RR) or "quality factor"... although "quality factor" can also mean RR divided by damping.  A higher RR is not always better, although abnormally low RR I think would tend to be relatively quiet.

As mentioned, "quality factor" can also mean RR/damping, where low damping means a longer "ring".  In looking at an Audacity plot of the tap recordings, the peak amplitudes are not much different, but the second piece appears to ring longer, as evidenced by the fatter plot as the taptone decays to zero.  (The peaks are cropped off in the plot, to focus on the decay)

So, if I wanted a louder violin, I'd opt for the second piece, although what you end up with is hugely dependent on what you do with it.

Hi Don 

thank you very much for your reply , is that plot , the plot for my recording , really appreciate your time it that’s the plot for my file ... and I have a question from you too ... when you say it also depends on what I do with it ,,, do you mean doing an precise and high quality job on it , or you mean ,, for different woods the design of the violin changes for you , I mean for a different piece of wood , you might be having different arching , thickness , fluting ? I have started to make violin two years ago ... and I love it ... I’m a mechanical engineer , but since I have good hands on skills , I decided to make a violin two years ago , although it was my first violin , but it turned out to be a good violin and it gave me much more motivation to move on and make more... also I read a lot and watch a lot of videos ... although on my first violin I ruin one top piece .... but eventually I made it over a year ... now I am going to make the second one ... but I want to again read and learn more stuff ... 

[Arsalan]

4 hours ago, HoGo said:

I think it is completely silly/crazy idea to judge the wood just by listening to recording of being tapped.

Just very slight difference in size of the pieces will result into different tones as will even very slight difference n holding and tapping position. These two sound quite far apart in pitch so either the pieces are VERY different in stiffness/density/etc. or they are not exacty same to start with.

I've made several very succesful instruments out of wood rejected by other folks - theorists because of "not suitable tap tones" or similar crap.

I see that you finished your first violin so I'd suggest to concentrate on building techniques and mastery of tools and workmanship for the next few at least before bothering with esotheric wood selection processes and similar distractions - that will just slow down your progress. Just sharpen your gouges and planes and make some shavings.

Hi Hogo 

thank you for your reply, I got your point and I think yes it’s better to send time , building and shaving and carving so I learn more and gain skills ... although I wanna tell you , as I have been making parts , machining and stiff like that .. a lot 

Whoever saw my first violin could not believe it’s the first one someone make ,,, and honestly a few master has told me it sounds great , but I have spent significant amount of time on it ... did my best .. and also I indeed learn like making a few violin. By this first one as I went very slow and tried everything on sample woods several times .. so I learned some , but on the other hand , I realized there is a huge range of skills and I think every violin I make I will learn new stuff .. maybe for the first 10 or 20 violins ... I hope I will have time to do so ... 

anyway I have a question too , I appreciate if you can tell me , what would be your criteria for a piece of wood ? Top or back ? It would really be appreciated if you can teach me some good points on this ... 

thanks again for your recommendation and help 

[Arsalan]

Just now, Arsalan said:

Hi Hogo 

thank you for your reply, I got your point and I think yes it’s better to send time , building and shaving and carving so I learn more and gain skills ... although I wanna tell you , as I have been making parts , machining and stiff like that .. a lot 

Whoever saw my first violin could not believe it’s the first one someone make ,,, and honestly a few master has told me it sounds great , but I have spent significant amount of time on it ... did my best .. and also I indeed learned, as much as making a few violins. By this first one as I went very slow and tried everything on sample woods several times .. so I learned some , but on the other hand , I realized there is a huge range of skills and I think every violin I make I will learn new stuff .. maybe for the first 10 or 20 violins ... I hope I will have time to do so ... 

anyway I have a question too , I appreciate if you can tell me , what would be your criteria for a piece of wood ? Top or back ? It would really be appreciated if you can teach me some good points on this ... 

thanks again for your recommendation and help 

 

[HoGo]

11 minutes ago, Arsalan said:

Hi Hogo 

thank you for your reply, I got your point and I think yes it’s better to send time , building and shaving and carving so I learn more and gain skills ... although I wanna tell you , as I have been making parts , machining and stiff like that .. a lot 

Whoever saw my first violin could not believe it’s the first one someone make ,,, and honestly a few master has told me it sounds great , but I have spent significant amount of time on it ... did my best .. and also I indeed learn like making a few violin. By this first one as I went very slow and tried everything on sample woods several times .. so I learned some , but on the other hand , I realized there is a huge range of skills and I think every violin I make I will learn new stuff .. maybe for the first 10 or 20 violins ... I hope I will have time to do so ... 

anyway I have a question too , I appreciate if you can tell me , what would be your criteria for a piece of wood ? Top or back ? It would really be appreciated if you can teach me some good points on this ... 

thanks again for your recommendation and help 

There were more than few folks aspiring at luthiery with machinist background who found out it was much more involved job than just making and assembling parts (though basicly it IS the process). The good think is that you have advantage of knowing what are high tolerances and possibly technical view at the process but there is much more to it that is different or not related to machinists work.

Good masters will always encourage you and be positive to you even if your violin wouldn't get 10 points out of 100 at a competition because any first attempt will not be perfect (and theirs were not as well). You should become your own honest judge by learning how the violin should look and sound.

The more I build the more I see thet the devil is in details and wood is just one of zillion of details (that's what Jezzupe wanted to say) and you can only judge your wood selection AFTER you mastered the other details. No one else can come and tell you with any level of certainty that you fiddle sounds like crap (or like a Strad) because you selected bad(or great) piece of wood but they will be able to see if there is potential in your work after looking at your carving skills or workmanship.

I would pick the piece that is on the top of the heap, just like I do with T-shirts in the morning. :-)

[Don Noon]

3 hours ago, Arsalan said:

... when you say it also depends on what I do with it ,,, do you mean doing an precise and high quality job on it , or you mean ,, for different woods the design of the violin changes for you , I mean for a different piece of wood , you might be having different arching , thickness , fluting ? 

Mostly I think it's getting the basic arching and graduations in a good zone, with good workmanship.  Dense wood will want to be thinner than lighter wood, although there is some debate about whether the arching should be adjusted as well.  I keep the same arching, and just vary the thickness.