Tap tone test , top plate

[David Beard]

44 minutes ago, David Burgess said:

So your contention that the old Cremonese makers didn't use tap tuning is based on their not having known the frequency of the notes in hz, and their not having used FFTs? So the validity of your contention relies on your personal definition of tap tuning?

No. It's based on its current failure.  Plus the notion of overly precision freqencies targets being both historically inconsistent, and prone to engendering higher Q resononces that I think are a bad and backwards goal.

 

It's just an opinion by the way.

[Don Noon]

49 minutes ago, David Burgess said:

So your contention that the old Cremonese makers didn't use tap tuning is based on their not having known the frequency of the notes in hz, and their not having used FFTs? 

A scientific-ish person who had no reference frequencies but wanted to use taptones in a non-Hutchins sort of way could make small reference planks and match them to the taptone of the free plate, as a way to document the taptones of each instrument.  Later, when the goodness of a violin became known, they could use the planks to repeat the taptones on another violin.  And discover it doesn't make a hell of a lot of difference.

11 hours ago, Advocatus Diaboli said:

Modes 2 and 5 on three free plates.  Make of it what you will.

I tried to make something out of it, or at least see what the frequencies are.  Plate 1 was unclear, 2 a bit better, and 3 the best, sortof... if clarity of a taptone is what you're looking for.  They were all relatively unclear, when compared to the way I record taptones (not sure if it's the plate or the recording or the method that is the big difference).  If indeed these are real violin plates, the best I could say is that plate #3 appears to be stiffer (or a smaller model) than my #21.  That's not saying a whole hell of a lot, but that's also my take on taptones overall.

[Don Noon]

11 minutes ago, David Beard said:

... higher Q resononces that I think are a bad and backwards goal.

It's just an opinion by the way.

My goal is to have lower Q resonances in the lower frequencies (below ~1200 Hz) where high, narrow peaks are a problem for evenness and wolf tones, and higher Q above that, where the peaks are too close together to cause problems, and you want good amplitude.  I don't think it's an unreasonable goal, as the lower frequencies involve more back plate flexing.

[David Burgess]

3 hours ago, David Beard said:

No. It's based on its current failure.

What is its failure rate?

And what is the source of your failure rate information?

_____________________________________

David Beard further wrote:

"Plus the notion of overly precision freqencies targets being both historically inconsistent, and prone to engendering higher Q resononces that I think are a bad and backwards goal."

Targeting the highest amplitude of a resonance at a specific frequency doesn't necessarily have anything to do with that resonance being peaky or having low damping. The point of highest amplitude can just as easily be the highest point of a  very broad curve.

[David Burgess]

15 hours ago, Marty Kasprzyk said:

One definition of a great violin violin is it is a violin that a great player wants to play.

But great player told me that he owned his Strad violin for seven years before he even began to like playing it because it had so many difficult to control and quirky notes.   

I asked him why he stuck with it for so long.  He said it made him a much better player because he had to learn how to overcome all these problems.  I said if he wanted to be an even better player he should be using one of mine.

Great humor, subtly incorporating high wisdom, as is usual for you.

[David Burgess]

10 hours ago, David Beard said:

Pythogoras gives the idea of associating ratios with musical intervals.  Ancient yes.  Related to tap tuning? No.

The tap tuning stuff is only as ancient as Hutchins and the Catgut Society.

I will await your proofs, those which have more viability than your dogmatic assertions.

[David Beard]

32 minutes ago, David Burgess said:

I will await your proofs, those which have more viability than your dogmatic assertions.

You have more rhetorical stamina than I do.  That doesn't your projection of modern tap tuning onto old making valid.

I can't know in any absolute way. But in my opinion it is very unlike the old makers did anything close to modern tap tuning.

Bit that's just an opinion.  I also don't think modern tap tuning is well founded.  Also, just an opinion.

 

 

[Michael Darnton]

 

I believe the original blame falls on Fetis and Savart rather than Hutchins:

[Michael Darnton]

More history from Anders Buen:

http://www.akutek.info/Papers/AB_Violin_acoustics_history.pdf

[Mark Norfleet]

2 hours ago, Michael Darnton said:

I believe the original blame falls on Fetis and Savart rather than Hutchins:

Thanks Michael!  I was pretty sure it pre-dated Hutchins, but didn't have a ready reference in mind.
I'm pretty sure this was the first book I read about violin making.  I wonder if I should re-read it to see if there's any content  pertinent to what I've been doing for the last 45 years...   

 

[Michael Darnton]

@Mark Norfleet It was my first violin book, too. I was 14 and had spotted it in the book store. After Christmas I used Xmas $$ to go buy it. Many years later my mom told me that when I went back to school in January she snuck into my room and took a look at it, read a bit, and thought "Well, that's a waste of money! This is much too complex [or some similar word]. He's never going to do that!"

It just took me a while to get around to it, though that 16 year span that it took me to get to it looks like a tiny length of time now.

[Advocatus Diaboli]

9 hours ago, Don Noon said:

A scientific-ish person who had no reference frequencies but wanted to use taptones in a non-Hutchins sort of way could make small reference planks and match them to the taptone of the free plate, as a way to document the taptones of each instrument.  Later, when the goodness of a violin became known, they could use the planks to repeat the taptones on another violin.  And discover it doesn't make a hell of a lot of difference.

I tried to make something out of it, or at least see what the frequencies are.  Plate 1 was unclear, 2 a bit better, and 3 the best, sortof... if clarity of a taptone is what you're looking for.  They were all relatively unclear, when compared to the way I record taptones (not sure if it's the plate or the recording or the method that is the big difference).  If indeed these are real violin plates, the best I could say is that plate #3 appears to be stiffer (or a smaller model) than my #21.  That's not saying a whole hell of a lot, but that's also my take on taptones overall.

This is the ‘thud’ of three golden period Cremonese plates.  The first is a top plate from c.1705, the second and third are a back and top from a different violin. 

[Michael Darnton]

The lack of high frequencies would appear to be possibly meaningful!

[Don Noon]

23 minutes ago, Michael Darnton said:

The lack of high frequencies would appear to be possibly meaningful!

Or not... hard to say.

Since free plate taptones are mostly edge flapping (which doesn't happen when assembled), any micro cracking, absorbtion of sweat, etc. at the edges might skew the result.

54 minutes ago, Advocatus Diaboli said:

This is the ‘thud’ of three golden period Cremonese plates.  The first is a top plate from c.1705, the second and third are a back and top from a different violin. 

Are they any good when assembled?

Is the back plate #2 or #3?  Year?

Can you record free plate taptones of a new build, recorded the same exact way, for comparison?

[Michael Darnton]

But Don, it doesn't matter the source: that is what they are, and they do what we like (most of us except for jealous violin makers, anyway). If drenching the edges of my tops and backs with sweat makes them sound like Strads, that's OK by me.

Anyway, I guess that's probably the cause of the "thud"--interesting to see it on an FFT.

[Marty Kasprzyk]

33 minutes ago, Michael Darnton said:

But Don, it doesn't matter the source: that is what they are, and they do what we like (most of us except for jealous violin makers, anyway). If drenching the edges of my tops and backs with sweat makes them sound like Strads, that's OK by me.

Anyway, I guess that's probably the cause of the "thud"--interesting to see it on an FFT.

I don't have a Strad top plate here at the moment but if I just say "thud" and "ring" it appears that "thud" doesn't have much output around 2000Hz.  But at higher frequencies they are similar.

[Advocatus Diaboli]

40 minutes ago, Don Noon said:

Or not... hard to say.

Since free plate taptones are mostly edge flapping (which doesn't happen when assembled), any micro cracking, absorbtion of sweat, etc. at the edges might skew the result.

Are they any good when assembled?

Is the back plate #2 or #3?  Year?

Can you record free plate taptones of a new build, recorded the same exact way, for comparison?

#2 is the back plate.  This one is towards the end of the golden period, depending on how you define the golden period.  

The first top is off of an instrument that’s in for some resto work, so I’m hesitant to try and call it a good or bad instrument.  It feels like it has some potential, but it’s also seen better days.  The second instrument is a good concert instrument when it’s having a good day.  I’ll record some of my free plates when I’m back to the shop. 

[Don Noon]

55 minutes ago, Michael Darnton said:

 If drenching the edges of my tops and backs with sweat makes them sound like Strads, that's OK by me.

My point is that drenching the edges of the plate might make the FREE PLATES thud like a Strad, but what happens in the rest of the plate in the assembled instrument could be a far different story.

It is also interesting that the 1705 plate is much thuddier than the later Golden Era one... so more thuddy might not be as good as modest thuddy.

In any case, I don't have any highly invested belief in any of these ideas, other than that the laws of physics and acoustics have to hold true.  The only thing I conclude from my observations is that very old violins are doing something different with those laws, compared to modern.  I want to find out what that is, and my best guess is that something has happened to the wood properties over time.  I seriously doubt they were that way when new.

[Marty Kasprzyk]

1 hour ago, Michael Darnton said:

But Don, it doesn't matter the source: that is what they are, and they do what we like (most of us except for jealous violin makers, anyway). If drenching the edges of my tops and backs with sweat makes them sound like Strads, that's OK by me.

Anyway, I guess that's probably the cause of the "thud"--interesting to see it on an FFT.

I don't have a Strad top plate here at the moment but just saying "thud" and "ring" shows that "thud" doesn't have as much output at 2000Hz that "ring" has in an FFT which is an dB vs. frequency plot.

It is interesting to show that in the time domain my verbal "thud" sound (on the left of the attachment) is shorter in time than my "ring" sound.  This makes sense in that a ringing sound goes on for a while.

For a "thud" sounding plate this means that the vibration energy is quickly transferred to sound energy--the "thud" sounding  plate is an effective sound producer whereas a "ring" plate isn't as effective at producing sound so it goes on longer to transfer the same amount of energy. I  believe "thud" sounding plates are probably quite light and that a "ring" sounding plates are heavier.

 

 

[David Burgess]

17 minutes ago, Marty Kasprzyk said:

For a "thud" sounding plate this means that the vibration energy is quickly transferred to sound energy--the "thud" sounding  plate is an effective sound producer whereas a "ring" plate isn't as effective at producing sound so it goes on longer to transfer the same amount of energy.

Is that what's happening when you tap on a sheet of rubber? It gives a "thud" sound because it is an effective sound producer?

[Don Noon]

1 hour ago, Marty Kasprzyk said:

For a "thud" sounding plate this means that the vibration energy is quickly transferred to sound energy--

The energy is going somewhere... but I don't think it's certain that is goes into sound.  Sure, there is a Bissinger study that concludes that, but the measurements have a lot of uncertainty, and I'd like to see some theoretical rationale explaining how that could happen.  Right now, it's unexplained.

Energy can be lost in damping, or a taptone could be like a gong, where the initial hit (thud) excites a mode that transfers its energy into other modes.  I have had spruce wedges somewhat like that, where I couldn't get a clear ring, as the bending mode trasferred its energy back and forth between a nearby twisting mode.

[Advocatus Diaboli]

These thuddy plates are incredibly lively when tapped.  The felt response is short, but you can feel a lot more movement than on more bell-like plates.  I know this is all incredibly subjective…

[Don Noon]

2 minutes ago, Advocatus Diaboli said:

These thuddy plates are incredibly lively when tapped.  

That would argue for wood with a high radiation ratio, or low damping in the higher mode frequencies, or both.  Or magic.

[Advocatus Diaboli]

7 minutes ago, Don Noon said:

That would argue for wood with a high radiation ratio, or low damping in the higher mode frequencies, or both.  Or magic.

I suspect a lower radiation ratio, just based on the mass and thickness in relation to the free plate modes, but would believe low high frequency damping. 

[Don Noon]

Now we're getting somewhere.