Plate tuning again...

[Jose Catoira]

I am just finishing the plates on the second of a pair of 5 string fiddles I was comissioned to make. 

 

 

 

The wood choice was the same for both instruments, fronts came from the same log and backs as well. 

 

 

I have never been trully convinced by platetuning but there is no harm in measuring things, maybe they'll come in handy someday. 

 

Both backs were made using the same archings, I was very careful about it. 

 

It resulted in a near perfect match of frecuencies and thicknesses. Both backs are the same. 

 

 

Now, the fronts

 

I made one with a very low arch, just over 14mm. I was aiming for a 305hz mode 5 before bassbar, which I got to with an overall thickness of 2.9mm-3.0. Slightlly thicker between Ffs. 

 

The second one I am tuning right now, the arch is higher, 16 mm. Wood from the same tree. I am at 324hz mode 5 before bar and overall thickness of 2.4mm. Sacconi numbers they all are. 

 

 

 

Am I correct if I draw some conclusions from this ?

 

Higher arch, gives me a stronger front resulting in raised tap tones and decreased thickenesses?

 

 

 

 

 

[Peter K-G]

I am just finishing the plates on the second of a pair of 5 string fiddles I was comissioned to make. 

 

 

 

The wood choice was the same for both instruments, fronts came from the same log and backs as well. 

 

 

I have never been trully convinced by platetuning but there is no harm in measuring things, maybe they'll come in handy someday. 

 

Both backs were made using the same archings, I was very careful about it. 

 

It resulted in a near perfect match of frecuencies and thicknesses. Both backs are the same. 

 

 

Now, the fronts

 

I made one with a very low arch, just over 14mm. I was aiming for a 305hz mode 5 before bassbar, which I got to with an overall thickness of 2.9mm-3.0. Slightlly thicker between Ffs. 

 

The second one I am tuning right now, the arch is higher, 16 mm. Wood from the same tree. I am at 324hz mode 5 before bar and overall thickness of 2.4mm. Sacconi numbers they all are. 

 

 

 

Am I correct if I draw some conclusions from this ?

 

Higher arch, gives me a stronger front resulting in raised tap tones and decreased thickenesses?

 

Higher arches gives stronger plates and higher tap tones for the same thickness

[Peter K-G]

Jose,

 

You have discovered something only three people on maestronet can master. It is possible to reproduce plate weight, graduation and taptones for wood with very different properties. But the tuning starts when you do arching.

[Oded Kishony]

Jose,

You have discovered something only three people on maestronet can master. It is possible to reproduce plate weight, graduation and taptones for wood with very different properties. But the tuning starts when you do arching.

I have discovered that you don't pay attention very well. The OP says he used wood from the same log -So no "very different properties" . And he never mentioned any weights.

Jose, we will all be very interested if these violins sound the same or very different.

Oded

Oded

[Jose Catoira]

Oded, I must admit I am poohing my pants a little over this, the first fiddle sounded terrific and these people are rather close, they'll get to compare. 

 

 

The idea of using all same wood was exactly that, trying to minimize the number of different variables and seeing changes due to arching shapes. 

 

Interesting is to note that I now have just below average Strad Thickness ( as per Sacconi), and the mode 5 is close enough to where I want it at 308 hz. A low density bass bar and more triangularly shaped profile will put it to up to 345hz easily.  

 

 

I have recently purchased a load of maple enough for 50 backs, pretty figure, nice look, 0.57 density. That will allow me to be rather consistent in my making once I find the combination that works. I am looking into doing the same for my spruce next. 

[Peter K-G]

I have discovered that you don't pay attention very well. The OP says he used wood from the same log -So no "very different properties" . And he never mentioned any weights.

 

 

I read Jose's post very carefully Oded. You don't understand my post, but I believe that Jose is about to.

 

Jose, for the record my 4 last tops with spruce SG from 0,37 to 0,49, arch height 13,8 - 16,3

Every one of them 307-310 Hz without bass bar and 345 Hz with bass bar, weighing 65-70 g, graduation 1,9 - 2,9 mm, bass bar 10 - 12 mm, different shape for different bass bar wood properties.

 

Good luck

 

Peter

[actonern]

"You have discovered something only three people on maestronet can master. It is possible to reproduce plate weight, graduation and taptones for wood with very different properties. But the tuning starts when you do arching."

Sorry, Peter, I don't usually read plate tuning related posts, but I seem to have found this one.

Are you merely suggesting that 3 people have mastered a particular method, or that it is only by application of this method that excellence can be achieved?

 

If the latter, have you sold any instruments?

[Don Noon]

I am very interested to see how these two fiddles compare, with the attempt to limit the variables.  I would expect the higher arch, thinner grads to have a cleaner, more refined tone but less power (mostly due to less amplitude in the transition hill, ~1khz).

 

I am not interested at all in mastering methods that I believe to be pointless, but my beliefs can be changed with good evidence or solid logic.

[Oded Kishony]

By the way, since the Cremonese makers finished their plates from the outside it was extremely unlikely, if not impossible, that they tuned their plates to some pre determined frequency.

oded

[Peter K-G]

"You have discovered something only three people on maestronet can master. It is possible to reproduce plate weight, graduation and taptones for wood with very different properties. But the tuning starts when you do arching."

Sorry, Peter, I don't usually read plate tuning related posts, but I seem to have found this one.

Are you merely suggesting that 3 people have mastered a particular method, or that it is only by application of this method that excellence can be achieved?

 

If the latter, have you sold any instruments?

 

Let's stay with that it's a method and be friends. I'm not in this business. Jose wants his top to be 308 Hz without Bb and 345 with. Three registered Maestronetters can do this. But keep in mind that most of the readers are Guests, it's almost always 10/100 registered users/Guests ratio viewing this forum. Platetuning threads are magnets, no wonder you found it

 

I am very interested to see how these two fiddles compare, with the attempt to limit the variables.  I would expect the higher arch, thinner grads to have a cleaner, more refined tone but less power (mostly due to less amplitude in the transition hill, ~1khz).

 

I am not interested at all in mastering methods that I believe to be pointless, but my beliefs can be changed with good evidence or solid logic.

 

It is possible to have both Power and clean refined tone. The amplitude in the transition hill region is an indirect consequence of plate balances. The ~1 KHz peak, you will find in almost every violin with strong clean B1 modes is harmless if the other things are right. You liked a violin and measured the spectrum from one of the maker who master this pointless method He is in to Del Gesus.

[Jose Catoira]

It is measurable, that is for sure. Not sure it gives definite answers and perfect instruments, but some good makers use it and they get consistent results. It is certainly a little more work that not doing any measuring at all and just sticking to arching templates and thicknesses from a Strad poster. 

 

Once at Oberlin Accoustics somebody was concluding that even though mode analizing was as addicting as cocaine, it really didn't help to make a better instrument. Still, the data may give an understanding and a consistency to what we do.

 

Let's say, I make a fiddle that works superb, and make 30 of the same, with the same numbers, same wood, arching.... and then make one with different numbers, blablabla, that sounds like total tzai-su, then I know something.

 

At least that is the theory here...