Peter KG's Bench

[Don Noon]

B mode frequencies went DOWN with the chinrest added? That's unusual.

Edit: oops. I meant "UP", which I guess is only fair since you had your numbers reversed too.

[Peter K-G]

? Of course B1- & B1+ go down when you add Chinrest!

 

(I noticed I had the without and with CR switched in the text - post edited)

[Peter K-G]

It's now a good mellow sounding violin, not a Cannon but more like a dark sounding DG.

I could have left a little bit more wood in the middle of the backplate,(B1+ 527 now) but it will be over 540 in the winter

Problem areas:

A0 frequency to high and too dominant (taking down B0 should help but for that another fingerboard with lower frequncy is needed)

- Too great soundbox volume in combination with oversized f-holes?

B1- has higher dB level than B1+ (so has some DG's, Plowden, Ex Vieuxtemps)

- DG arch style?

The violin is too easy to play, responsive but not enough resistence to the bow. (It does not pop like I want them to)

- More suitable bridge could help

Thank you for your support Patrick.

This project is finished

Next - Opus 6

[Peter K-G]

I thought I was done with this violin I was not. I have played and played and played

 

I was handling it like #5 but this violin requires completely different bowing technique. It's really lovely but kind of gives too much of everything so it does not need pressure. And it pops, but it comes with a millisecond of delay, and with really gentle, slow speed bowing.

 

I was expecting a cannon that would need powerful bowing - I got something quite the opposite; carrying capacity with not much bowing.

 

awesome surprise!

[Peter K-G]

... and still playing .. and playing, can't stop

This violin is addictive. I'm starting to understand why there are Strad guys and DG guys. (Strad guys cheat from time to time with DGs)

 

There is one wolf note (A+) up on G string and one on E string up high (D+), not too bad, but if I hit those notes a little sharp the tones starts to vibrate rapidly +/- some Hz. I must say I haven understood real wolf notes before now. I can make them go away with rubber between D and A in front of the tailpiece.

 

It's now a howitzer at least

[Peter K-G]

Okay, back to Strads

 

I have thought about making several plates, outside molds and so on... But I'm simply going to make another violin. This time no heat treatment only seasoned wood, stored 10+ years inside (In Scandinavia humidity varies from 0% - 70%, winter/summer)

 

[Peter K-G]

Thanks Patrick!

 

I got rid of the wolf notes with a longer sound post and a bridge with higher frequency (didn't measure frequency it was considerable higher)

The sound is now pure and "boomier" with more pop and resistence to the bow. B1+ is also higher 541 Hz and dB level is almost on B1- level.

(humidity 60%)

 

Unfortunatly it already outcompeats #5 in power. but it is not as sweet.

 

I'm thinking of in which direction I want to go with #6

 

edited: A0 and B0 also brought down to 282/276

[Peter K-G]

No time to kick off #6, business is taking almost all of my time at the moment... so I play my Cannon instead

 

For what it's worth I have learned more and confirmed at least for my self the importance of Helmholtz resonance (A0, A1),  more understanding on how this influence the violins whole character.

 

Optimizing violin body volume & f-hole area is really important! This is one key factor in differencies between Strads & DGs.

[Peter K-G]

Ebony tailpieces should be banned!

 

This is the second time I have used an ebony TP - never again. Tailpieces should be light and resonate in harmony with the violin, not too strong.

 

I think that tailpieces are the root to most wolf notes. I Think I found the root cause to wolfs on my Late Jakob projekt. Previous adjustments where only hidning the problem.

 

I found this by constantly monitoring the frequencies as the violin developed. I started to see a frequency (512 Hz, B1+ split by TP mode) gradually becoming stronger than B1-/+ modes

 

Now, Very strong TP mode at 130 Hz and 520 Hz ©, wich took down the B1+ dB level and splitting it.

I had the same problem with violin #4 but not at a note. (125 Hz/500 Hz)

 

It obviously takes a long time for an old violin to settle after correction. The woodyness that I was looking for is now there and B1 modes are stronger than A0. It's lovely, people like it better than violin #5.

 

This is not a real solution but a fix to take out the 520 Hz TP mode (earplug):

 

 

The correct B1+ with CR is 534 Hz (not 541 as prev. post) and with the fix it's also stronger than B1-,

as it should be.

 

Humidity is 40%

 

I should be working on Opus 6 !!!!!!

 

 

[Don Noon]

I think that tailpieces are the root to most wolf notes.

 

I think oppositely... they are a potential cure for wolf notes.

They can make wolf notes worse, if not adjusted correctly.

 

It appears (as best I can determine from the photo) that you have a very long free length on the tailgut, >>5mm.  That would allow a strong TP resonance in the lower playing frequency range.  I have had no trouble with ebony or even heavier metal tailpieces, as long as I keep the tailgut free length below 5mm.  I only do something different if the instrument has an overly strong, wolfy B1+ resonance, then I try to mode match and split it.

 

I have had more trouble with very light tailpieces, where a torsional mode that is normally below the playing range can come up in frequency and cause problems on the lower G string.

[Carl Stross]

 

Ebony tailpieces should be banned!

 

This is the second time I have used an ebony TP - never again. Tailpieces should be light and resonate in harmony with the violin, not too strong.

Great point ! I too think that the lighter a TP is, the better the violin sounds. Maybe carbon fibre TPs are the way to go ?

[curious1]

I think oppositely... they are a potential cure for wolf notes.

They can make wolf notes worse, if not adjusted correctly.

 

It appears (as best I can determine from the photo) that you have a very long free length on the tailgut, >>5mm.  That would allow a strong TP resonance in the lower playing frequency range.  I have had no trouble with ebony or even heavier metal tailpieces, as long as I keep the tailgut free length below 5mm.  I only do something different if the instrument has an overly strong, wolfy B1+ resonance, then I try to mode match and split it.

 

I have had more trouble with very light tailpieces, where a torsional mode that is normally below the playing range can come up in frequency and cause problems on the lower G string.

What would you consider light and what would be heavy? (Specify w/wo tuner)

[Peter K-G]

Thanks for your comments.

 

I just cut the top wood wedges for opus 6 and measured them. The wood is on the edges of what I would like to make a violin of. Too low density and it does not ring so high. Speed of sound D.Noon way is also on the edge.

 

 

Go or no Go ?

[Don Noon]

Curious1,

Light would be boxwood or other lower density stuff, ~9g

Normal ebony (not hollowed) ~16g

I regularly use metal tailpieces with integral tuners, sometimes over 30g, and haven't noticed any problems, other than you'd get with a heavy chinrest.

[Don Noon]

 

Go or no Go ?

Looks good.  If you decide not to use it, send it to me.

[Peter K-G]

[Peter K-G]

My new Stanley works:

 

 

It's a Go for the top wood and the back too. I want to try to make a violin with less performance wood.

The violin will be named Stockholm where I bought the wood.

 

I will save my really high performance wood for opus 7

 

 

 

 

[Don Noon]

I will save my really high performance wood for opus 7

 

I'm still trying to decide what "high performance" wood is.  What do you think it is?

[Peter K-G]

Highest possible ring/speed of sound (~6500 m/s), over 0,42 density for spruce. (at ~6 % MC)

Then It's possible to bring down the volume and weight to 65 g together with a M5 of 345 Hz.

Such a top won't be so sensitive to climate change as the volume is very low. This also makes the violin extreamly reactive.

But It is not a high arched Willemotte or Jackson Strad

The same princip with back.

[Peter K-G]

Now that I wrote this I don't like my Stockholm top wood anymore

[Don Noon]

Need my shipping address?

 

 

and good luck finding 6500 m/s wood.  The highest I've seen so far is 6200 on a piece of .50 density Sitka, 35 years old.

[Peter K-G]

It sure would be interesting to measure with a lucchi meter.

 

Now glued together it shows 5600 (7020 Hz) with your 2LF method.

I think that your method is a good indication of C, but that it's higher in reality?

 

From Patrick's book there is a table with 35 examples of violin tops with density from 0,36 - 0,50 and C from 5200 - 6630 (measured with a lucchi meter)

 

If the finished violin is bad I'll send it to you

[Don Noon]

I think the wood whacking method generally finds slightly lower C than it "really" is, possibly due to lateral dissipation of the compression wave.  In long, thin pieces cut from a bigger slab, I see higher numbers.

For me, it's close enough, and I can't see any benefit to greater precision... especially if it takes more time and money to get more accurate numbers.

[Peter K-G]

Yes, I'm doing it for three specific reasons

 

- It correlates very well with ring mode of wedges and it seems to give good comparison data

- Old timbermen use to choose wood for supporting beams by hitting end wood with a hammer.

- It's easy

 

when I'm choosing tone wood I select the highest ringing I can find.

 

Back:

 

[Don Noon]

In long, thin pieces cut from a bigger slab, I see higher numbers.

 

Wrong... at least this most recent time.

I just now cut off a couple of bass bars from an old Sitka set:

side A:  wedge 6176, bassbar 6035

side B:  wedge 6073, bassbar  5923

 

That's less than 2.5% difference from bar to wedge, which isn't a big deal, and there might be residual effects from being freshly cut, but I thought I'd correct my previous statement.

 

I do look for very high speed of sound in spruce, but for maple, I'm not convinced that exceptionally high along-grain speed of sound is even desirable.