Ervin Somogyi's "Principles of Guitar Dynamics and Design"

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aaron peacock

Posts: 141
Joined: Apr. 26 2020
From: Portugal

Ervin Somogyi's "Principles of ...

https://esomogyi.com/articles/principles-of-guitar-dynamics-and-design/

1) I'm ignorant if Mr. Somogyi is here on the forum even
2) I'm sure many people on this forum have more decades experience as luthiers and my have their own opinions
3) This may possibly be a useful link getting at the principles, rather than the implementation details that are often spoken of by our resident experts as merely parts of whole systems, and not to be taken in isolation, hence principles and concepts.

I enjoyed it, but I'm a noobie to this noble craft, what do I know...
(a bit about acoustics and playing instruments and recording them...)

REPORT THIS POST AS INAPPROPRIATE | Date May 9 2020 21:23:03

Andy Culpepper

Posts: 3023
Joined: Mar. 30 2009
From: NY, USA

RE: Ervin Somogyi's "Principles... (in reply to aaron peacock)

My former guitar making teacher is a very learned man and he was fond of repeating two things: "The map is not the territory", and "We all work from mental models".

What he was getting at is that as guitar makers, we may all have different theories about why we are getting the results we are getting, and that these theories may not be particularly fact-based, but they may still lead us to good results. There are some who talk about the guitar as an air pump, some who talk about salt on braces, some who look to chladni patterns, some who believe it's all in flexing with the thumbs. They may all get good results, and they may all be partially wrong about why they are getting good results.

When Mr. Somogyi describes the fundamental way that a guitar produces sound as "pumping air", he is factually and scientifically incorrect, even though a bit of that does happen at lower frequencies. That is a flawed mental model, but it still allows him to make good instruments! Not casting any shade on his art because he's created some incredible things both visually and I'm sure acoustically.

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Andy Culpepper, luthier
http://www.andyculpepper.com

REPORT THIS POST AS INAPPROPRIATE | Date May 9 2020 21:35:27

Tom Blackshear

Posts: 2304
Joined: Apr. 15 2008

RE: Ervin Somogyi's "Principles... (in reply to Andy Culpepper)

Andy,

I support your way of politely giving differences about certain tuning models and what Ervin had to say about his model tuning method.

There are many techniques that work well according to their treatment of the hand that uses them, and it's true that not all techniques have the same result.

I had to search for a long time before things started making sense with my fine tuning. But now I have a kinship with these techniques that proves to me to be advantageous toward finding excellent vowel tone.

_____________________________

Tom Blackshear Guitar maker

REPORT THIS POST AS INAPPROPRIATE | Date May 10 2020 3:43:25

RobJe

Posts: 731
Joined: Dec. 16 2006
From: UK

RE: Ervin Somogyi's "Principles... (in reply to Andy Culpepper)

quote:

some who believe it's all in flexing with the thumbs

I can only speak as a consumer but I wonder if this flexing is connected in any way to one of the things I do when I am checking out a guitar. I gently flex the soundboard under my thumb at the extremities of the bridge. Most of the good guitars I have played display a stiffness that falls within a fairly narrow range. Some of the looser ones I have tried have had booming bass or lack of any quality of sound. The one guitar to buck this trend is a Felipe V Conde A26, appearing to have a thick and stiff top but somehow being rather good despite this.

Rob

REPORT THIS POST AS INAPPROPRIATE | Date May 10 2020 10:12:40

Echi

Posts: 1132
Joined: Jan. 11 2013

RE: Ervin Somogyi's "Principles... (in reply to aaron peacock)

Andy probably quoted the letter of Fr. Sirvent, who claimed Torres once told him there are no secrets in his guitarbuilding but his knowledge/intuition in understanding the right flexibility of the plates by bending them with the fingers.

Well said and written Andy.

Re: boomy guitars, thin plates may drive you there. Nonetheless there are also boomy guitars with thick top: It comes to my mind a Sanchis Carpio a little too much bass oriented. I suppose it’s a matter of balance.

REPORT THIS POST AS INAPPROPRIATE | Date May 10 2020 16:01:46

Andy Culpepper

Posts: 3023
Joined: Mar. 30 2009
From: NY, USA

RE: Ervin Somogyi's "Principles... (in reply to RobJe)

quote:

I can only speak as a consumer but I wonder if this flexing is connected in any way to one of the things I do when I am checking out a guitar. I gently flex the soundboard under my thumb at the extremities of the bridge. Most of the good guitars I have played display a stiffness that falls within a fairly narrow range. Some of the looser ones I have tried have had booming bass or lack of any quality of sound. The one guitar to buck this trend is a Felipe V Conde A26, appearing to have a thick and stiff top but somehow being rather good despite this.

Rob

It sounds like you found a good heuristic that works for you. To stretch the map metaphor (maybe a little too thin), let's say that you filled in one important part of the map, like the grass.
You ascertained that if there's grass there, it's probably a good place to live and build a house. The fact that there's grass let's you logically infer that it rains there, giving you access to water, and that animals will come to eat the grass, giving you a potential food source. That will work out most of the time.
Now the Conde comes along, and you realize there's no grass, because you're on the beach! It's a different kind of territory, and now maybe your food supply is fish, but it's still a perfectly good place to live.

As guitar makers, we try to make as detailed maps as we can, or at least up to the point that it serves our purposes of making better guitars. Not just the grass, but the trees, the flora and fauna, the topography, etc, etc. The problem is we're making maps of territories that we will never see in detail, and there are a lot of tiny variables that make a place better or worse to live that are almost impossible to measure, some we don't even fully understand. And the territory changes with every guitar and every new piece of wood!

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Andy Culpepper, luthier
http://www.andyculpepper.com

REPORT THIS POST AS INAPPROPRIATE | Date May 10 2020 17:42:58

Tom Blackshear

Posts: 2304
Joined: Apr. 15 2008

RE: Ervin Somogyi's "Principles... (in reply to Andy Culpepper)

quote:

Now the Conde comes along, and you realize there's no grass, because you're on the beach! It's a different kind of territory, and now maybe your food supply is fish, but it's still a perfectly good place to live.

Please forgive my intrusion again but I find this philosophical dissertation interesting although somewhat divorced from the fact that we are always subjected to Guitars as wooden objects.

Once sound is recognized as a basic fundamental associated with creating a vowel tone, there is always going to be an understood way to gauge balance with-in certain perimeters of good tonal creation.

Once the top has received certain thinning and tapering, then we are open to take the sound wherever it will go from this point by microscopically polishing the fan braces to gain a more perfect balance; if needed.

However, I have found that this technique doesn't necessarily take the place of other techniques, as it assists them in creating total harmony; sort of like the final touch.

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Tom Blackshear Guitar maker

REPORT THIS POST AS INAPPROPRIATE | Date May 11 2020 17:50:50

Andy Culpepper

Posts: 3023
Joined: Mar. 30 2009
From: NY, USA

RE: Ervin Somogyi's "Principles... (in reply to Tom Blackshear)

quote:

Please forgive my intrusion again but I find this philosophical dissertation interesting although somewhat divorced from the fact that we are always subjected to Guitars as wooden objects.

Tom, my point of view is only my own, and I'm sure is at least as wrong as everyone else if not more so. I was just trying to provide a metaphor for how different makers arrive at their results in different ways but you have every right to snap me out of it

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Andy Culpepper, luthier
http://www.andyculpepper.com

REPORT THIS POST AS INAPPROPRIATE | Date May 12 2020 0:43:31

RobF

Posts: 1611
Joined: Aug. 24 2017

RE: Ervin Somogyi's "Principles... (in reply to Andy Culpepper)

I once decided to let a guitar tell me how it wanted to be built. It made me change its fingerboard from ebony to rosewood and insisted on a couple of other things that I can’t even remember. I thought it came out looking and sounding great, but a lot of people kept asking me why in heck did I do this, that, and the other thing the way I did. I gave up on trying to explain that I had nothing to do with it. Last I heard, it’s in India now, probably telling its new owner what they should be playing and exactly how they should be going about it.

That was one bossy guitar...

REPORT THIS POST AS INAPPROPRIATE | Date May 12 2020 3:11:48

Tom Blackshear

Posts: 2304
Joined: Apr. 15 2008

RE: Ervin Somogyi's "Principles... (in reply to Andy Culpepper)

That's OK Andy, no snap intended but to say I've tried just about every non electronic technique in the 58 years I've been building, and have settled on certain techniques that generally don't hurt sound, but even this doesn't prove things to be without defect :-)

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Tom Blackshear Guitar maker

REPORT THIS POST AS INAPPROPRIATE | Date May 12 2020 3:54:58

ernandez R

Posts: 737
Joined: Mar. 25 2019
From: Alaska USA

RE: Ervin Somogyi's "Principles... (in reply to aaron peacock)

I found access to the many sources of information invaluable in this beginning of my Luthery adventure. I’ve got a good enough bull **** filter to sift through it but at the same time I’m not so fixed so as to dismiss what I don’t understand.
I downloaded a number of books to my kindle at the very start and had to learn the hard way that there is some rubbish in print. I have rebuilt airplane wings the flew perfectly straight and level without a single adjustment more then once but was befuddled by some poor information in two well known guitar books: neck angle if you must know.

As I’ve come to terms with sonic qualities as they relate to how I build and what I expect my instruments to be I’ve realized how much is less science and more intuition with perhaps more luck.

Alin Carruth post quit often on the Delcamp about issues if science he has studied but almost always he adds an addendum where he notes that for all the science and measuring and recording that it might not matter and just build the guitar and see what you get.

I feel I’m at a point where voicing sound bars my be if benefit and had planed to be down in Texas about now hoping to pick Toms brain, also planed to visit Brian with a few of my local tops in hand to run through his testing regime, and visiting Ethan to play a few of his guitars to get an idea how he goes about getting his Flamenco sound.

I’m so many ways it seems we must expose ourselves to all ideas and let them... ferment in our minds letting it produce output we can call our own.

HR

_____________________________

I prefer my flamenco guitar spicy,
doesn't have to be fast,
should have some meat on the bones,
can be raw or well done,
as long as it doesn't sound like it's turning green on an elevator floor.

www.instagram.com/threeriversguitars

REPORT THIS POST AS INAPPROPRIATE | Date May 12 2020 15:14:12

Richard Jernigan

Posts: 3430
Joined: Jan. 20 2004
From: Austin, Texas USA

RE: Ervin Somogyi's "Principles... (in reply to ernandez R)

quote:

ORIGINAL: ernandez R

Alin Carruth post quit often on the Delcamp about issues if science he has studied but almost always he adds an addendum where he notes that for all the science and measuring and recording that it might not matter and just build the guitar and see what you get.

HR

A few years ago there was a lot of discussion on the net about string break angle at the bridge. Some people were saying you had to go to a 12-hole bridge to get it right, others said old school bridges were OK. With the help of some of Carruth's measurements of forces exerted by the strings at the bridge, and some published data about string material properties, it was a simple freshman physics problem to check out what the break angle had to be to keep the string from sliding on the saddle or jumping up off it. So I wrote it up.

A luthier friend liked the note I wrote up. He says he prints a copy and gives it to potential customers when they talk about break angle.

I was fairly sure my math/physics was in the right ballpark because instrument makers had been getting the break angle OK for centuries.

Years later the same luthier asked me whether I could analyze the difference between a flat top and a domed one. Based on a 43-year career in engineering, more than half of it in strategic missiles and space, I said the only way I knew to do the problem was complicated, time consuming, an computationally intensive. Then you would have to build a couple of guitars to check that the calculation was right.

So my recommendation was, just cut to the chase and build the guitars.

I like to quote Carruth (more or less): By measurement we can distinguish good guitars from bad guitars. We can't distinguish good guitars from great guitars.

RNJ

REPORT THIS POST AS INAPPROPRIATE | Date May 12 2020 17:12:32

Tom Blackshear

Posts: 2304
Joined: Apr. 15 2008

RE: Ervin Somogyi's "Principles... (in reply to Richard Jernigan)

quote:

I like to quote Carruth (more or less): By measurement we can distinguish good guitars from bad guitars. We can't distinguish good guitars from great guitars.

That's a quote worth remembering.

I recall a paper he wrote about one of my Miguel Rodriguez models I built for Berit Strong in Boston, years ago. (She is the former president of the Boston Classical Guitar Society).

Alan took his little black box to measure the tonal balance and found that the treble side balanced quite well with the bass side but didn't quite understand how the two met together in the middle.

From what I can remember, he said he would like to know how this technique was done according to his way of measurement but couldn't make it happen quite yet.

Any person who knows Alan might invite him on this list and see if he has an answer for what I can remember of this time. Perhaps he could also correct any of my memory about it.

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Tom Blackshear Guitar maker

REPORT THIS POST AS INAPPROPRIATE | Date May 15 2020 16:50:03

Tom Blackshear

Posts: 2304
Joined: Apr. 15 2008

RE: Ervin Somogyi's "Principles... (in reply to Tom Blackshear)

For those of you who would like to invite Al Carruth here to talk about fine tuning, I found his e-mail address, which is:

alcarruth@myfairpoint.net

and give him the courtesy of explaining how he can become a member of this list. Al is full of knowledge about guitar making.

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Tom Blackshear Guitar maker

REPORT THIS POST AS INAPPROPRIATE | Date May 16 2020 22:51:08