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  #61  
Old 11-19-2017, 04:15 PM
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Originally Posted by zeeway View Post
...If any luthier is still carving necks with hand tools, they must not value their time very highly...
Not necessarily. If a luthier offered one style/shape neck, then CNC could make economic sense. However, if they offer true custom variety, then the time required to program the shape, let alone the cost of the machine would be impractical. Hand carving is a little slower, but you can get wonderful results. My Klepper is the perfect example. I have a particular D-18 and I love the neck shape. Howard and I discussed this aspect of my build in great detail, which involved detailed measurements. Howard nailed the shape I wanted. This was a job for a skilled hand, not a precise machine.

To be clear, I'm not against precise machines. It's not only about picking the right tool, but knowing the right application.
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  #62  
Old 11-19-2017, 04:16 PM
printer2 printer2 is offline
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Originally Posted by murrmac123 View Post
All well and good , Alan, and what you are saying has been regurgitated a trillion times, but at no point has any maker ever come forward and produced a video (or even written an article with commentary and soundclips ) which demonstrates the process whereby they decide to remove a thousandth of an inch from this part or the other part of whatever brace they deem, with certitude, to require thinning, in order to achieve the required tone.

I am by no means demeaning the skill of hand builders ... the woodworking skills of many of the top builders approach the level of the top furniture makers ... but if the methods used to maximize tone can't be explained concisely and clearly .. well ... the "Emperor's new clothes " syndrome cannot help but spring to mind.
I did it. And is sounded lovely and blew people away, the sound just jumped off the top. No it did not self destruct after you read the message. But the bridge lifted and pealed off in a few months. Later I got around to looking at it closer I found the top distorted. Should have left on a couple more thousandth's of an inch. Wonder what it would have sounded like then?
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  #63  
Old 11-19-2017, 04:53 PM
mmasters mmasters is offline
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The secret to getting a great guitar for the least amount of money is to go factory built and play or hear a ton of them. Then you can cherry pick the guitar the factory got right. Luthiers seem to build better guitars on average but there are so many variables. The luthiers that have figured out the variables are rare, and cost a lot, like Froggy Bottom-who rarely ever builds a dud. But for the money you're far better off just going factory and hearing or playing a ton of guitars to find the one. Building guitars is far from an exact science.
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  #64  
Old 11-19-2017, 04:58 PM
AndrewG AndrewG is offline
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Originally Posted by andyspur View Post
I completely agree with Mr Tauber, and as soon as you start discussung what constitutes quality, things can get very 'sticky'. All I can say is that both my Martin and my Gibson probably fall into the 'factory built' category and I am fantastically happy with both of them every time I play them. My Brook however, it really is a class apart. I honestly don't know why, but I feel a connection with that guitar that I don't (quite) get with the others. Check out the Brook website to see a tour of their workshop, a converted farmhouse I think in Devon. Pretty much the definition of handbuilt these days I think, and making fantastic guitars.
And at a very reasonable price considering the company......*meant to say 'competition'*
I couldn't agree more; there's a picture in their archives of me and my (now long gone, sadly), Creedy Custom parlour with its ebony moustache bridge. Great guitars and good people to do business with.
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  #65  
Old 11-19-2017, 07:31 PM
Truckjohn Truckjohn is offline
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Quote:
Originally Posted by murrmac123 View Post
I totally get the top stiffness measurement thing (not part of this thread discussion so far, admittedly) ... but it seems to me that many builders like to propose an almost mystical , tai-chi kind of approach to their voicings, and I am not sure that I can altogether gel with that .

AFAIAC if it can't be measured, then it doesn't exist.
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Originally Posted by Steadfastly View Post
Now there is reasoning and thinking ability.
Its easy to say that.. And it sounds like it ought to be reasonable and straight forward...

But guitars are not can openers or blenders. With those things - if every part meets it's material specification and is assembled propery - it works as you would expect.

And with a guitar - action, nut, saddle, bridge, neck profile, neck set, fretwork, and intonation fall in like this. If you hit the dimensional target - all is well.

But with tone it's more complicated. Especially if you want to hit some sort of specific sound.

It's very easy to measure thickness of components. More time consuming to measure density and flexibility... Far more expensive and time consuming to measure Q or speed of sound in the plates... You can even take Chladni and interference patterns.... But wood is massively variable stuff... Even within the same piece.... What do you do with it?
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  #66  
Old 11-19-2017, 07:56 PM
Guildman Guildman is offline
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Originally Posted by stringjunky2 View Post
the difference between handbuilt/custom is that a target sound is going to be achieved more consistently because individual luthiers work with consideration to the properties of the materials in hand whereas a factory guitars are largely built to dimensional specs, which creates wider variations in the tonal results.
This struck me as a good insight. When it comes to building the details, the hand builts have jigs and fixtures that keep the build with a certain tolerance just as a machine would. It would be that extra consideration for the raw material properties that would seem to determine the outcome assuming all other quality control was in place.
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  #67  
Old 11-20-2017, 05:37 AM
rokdog49 rokdog49 is offline
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Originally Posted by robj144 View Post
I know this will get no love, but Magnum Opus guitars are made by hand without CNC machines as mentioned in their FAQ:

http://www.magnumopusguitars.com/faq.php

"Every MO guitar is 100% hand-made without the aid of CNC machines. We even make our Ebony, Koa or Bone bridge pins and our tuning machine buttons by hand."

There used to be a video on Youtube of their shop in Vietnam, I believe, and they are do everything by hand including the necks. It was neat. I can't find it now.

You got some love from me. Eastman's are built the same way in China minus the tuners and bridge pins.
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  #68  
Old 11-20-2017, 07:59 AM
charles Tauber charles Tauber is offline
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I wrote:

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Originally Posted by charles Tauber View Post
An interesting concept was put forth by David Pye called "the workmanship of risk", "workmanship using any kind of technique or apparatus, in which the quality of the result is not predetermined, but depends on the judgment, dexterity and care which the maker exercises as he works." (https://en.wikipedia.org/wiki/David_Pye_(furniture))

Much can be said about the concept and it implications for things "handmade". For a guitar maker, it might include making a guitar top thickness just on the edge of failure - one more stroke or two of the hand plane, sanding block, electric orbital sander, etc. and the top is too weak or not the right response.
You replied with,


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Originally Posted by printer2 View Post
I wish this example would go away. If two strokes of the sandpaper is left on it may last 10 hrs. If another stroke, then ten days. There is no way a builder will take an instrument just before the point of immediate failure if he wants it to last for years.
And then wrote,


Quote:
Originally Posted by printer2 View Post
I did it. And is sounded lovely and blew people away, the sound just jumped off the top. No it did not self destruct after you read the message. But the bridge lifted and pealed off in a few months. Later I got around to looking at it closer I found the top distorted. Should have left on a couple more thousandth's of an inch.
So which is it?
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  #69  
Old 11-20-2017, 08:26 AM
charles Tauber charles Tauber is offline
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Originally Posted by murrmac123 View Post
... but if the methods used to maximize tone can't be explained concisely and clearly .. well ... the "Emperor's new clothes " syndrome cannot help but spring to mind.
The short answer is you are criticizing something you do not understand.

As I've repeated here many times, my old fluid mechanics teacher used to say, "An art is a science with too many variables". There are many, many variables that contribute to and influence what sound a guitar is going to have. For simple, practical reasons, one can't measure and control everyone of them.

In science, applied and theoretical, one creates mathematical models of an object and its responses to inputs. Doing so allows one to create a mathematical equation wherein some result is equal to some relationship of variables. E=MC^2, for example. In very complex systems, those with many variables, there are too many variables to create a meaningful mathematical equation. The response of a guitar is one such complex system: that is, one isn't able to create an equation where these values of those variables repeatedly, reliably produce that result. In essence, that is what you are asking for.

In the absence of such a cause and effect relationship between a manageable number of variables, and their values, historically, results have been obtained using empirical methods - trial, error and observation.

In more recent times, the values of some specific variables can, and have been, measured by makers. That provides some useful input, but is still not a direct cause and effect: do this and you get that exact result (response or sound). These measurements can, and have been, made using a variety of methods some of which are subjective (by "feel" and hearing) and some of which are objective (using numerical measurements). For example, a subjective test is to flex a piece of wood in one's hands while an objective test is to measure the quantity of its displacement when subject to a load of a specific amount in a test fixture. Both yield the same information, though one is numeric and objective while the other is meaningful only to the one person performing the action. What that measurement means in terms of its effect on the final sound of the instrument is another question altogether: how the stiffness of the top material relates to the sound of the finished guitar.

At a seminar, Jose Romanillos taught makers to flex the top of a finished classical guitar to determine the correct amount of stiffness of "the system". No measuring instruments were used other than one's thumbs: when it feels like this, it will give the "correct" response. He went around the room and performed this test on each makers' instrument, explaining to them what they should do to the top thickness and/or bracing to adjust the stiffness to obtain the desired result. No amount of my writing about it will allow you to feel what the desired result is: you have to experience it first hand and have to use your own experience over numerous instruments to determine a cause and effect between this "feel" and that (desired) sound.

Other makers use more objective "scientific" methods, including vibration response testing.

Then there is the long discussion of what "maximize tone" means in practical terms. There is no single definition, no single target that is "maximize tone". It is a moving target. So now you have a non-universal target - one that changes depending upon who is discussing it - and a large number of variables that can be altered to effect "tone". Those don't lend themselves well to point solutions, but, instead, to a scatter of ways of accomplishing that.

Its easy enough to write a concise explanation of the methods, but it doesn't mean that they can all be understood by someone who has no experience with them simply by reading about them. "Put your thumbs here and press: it should yield/feel like this." Need it more concise than that?

Last edited by charles Tauber; 11-20-2017 at 08:47 AM.
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  #70  
Old 11-20-2017, 09:00 AM
JonWint JonWint is online now
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Quote:
Originally Posted by robj144 View Post
"Every MO guitar is 100% hand-made without the aid of CNC machines. We even make our Ebony, Koa or Bone bridge pins and our tuning machine buttons by hand."
This is marketing-speak. Do they make bridge pins, by hand, without a lathe?

The labor rate in Vietnam causes different capital cost investment decisions when outfitting the factory. In 2015, the hourly rate was 60 to 90 cents depending on location. At that rate it might be cheaper to resaw tops with handsaws and thickness them by hand planing and hand sanding versus using bandsaws/planers/thickness sanders.

Last edited by JonWint; 11-20-2017 at 09:05 AM.
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  #71  
Old 11-20-2017, 10:13 AM
Mycroft Mycroft is offline
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Originally Posted by mmasters View Post
The secret to getting a great guitar for the least amount of money is to go factory built and play or hear a ton of them. Then you can cherry pick the guitar the factory got right. Luthiers seem to build better guitars on average but there are so many variables. The luthiers that have figured out the variables are rare, and cost a lot, like Froggy Bottom-who rarely ever builds a dud. But for the money you're far better off just going factory and hearing or playing a ton of guitars to find the one. Building guitars is far from an exact science.
And which is worth more to you: time or money? How much time does it take to play a "ton" of guitars? How many hours? How many guitar shop visits? Not to mention the fact that "the one" that the factory got right is a moving target, because others are looking for it as well, so it may have been in the shop on Friday, but you got there on Saturday.

Not to mention, are we comparing Froggies (since that seems to be your perfection benchmark) with the average guitar line, a factory makes, or their best one? How much price difference is there actually between the average Frog and a Martin Authentic?
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  #72  
Old 11-20-2017, 10:35 AM
Howard Klepper Howard Klepper is offline
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Many people--I think most people when they are asked the right questions--turn out to care not only about what an object is, but also about how it came to be.
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  #73  
Old 11-20-2017, 02:14 PM
Alan Carruth Alan Carruth is online now
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murrmac 125 wrote:
" at no point has any maker ever come forward and produced a video (or even written an article with commentary and soundclips ) which demonstrates the process whereby they decide to remove a thousandth of an inch from this part or the other part of whatever brace they deem, with certitude, to require thinning, in order to achieve the required tone."

and Charles Tauber replied:
"The short answer is you are criticizing something you do not understand."

Thanks Charles.

To put his answer another way....

It's fairly easy to show that the guitar is built up of very nearly linear parts. It takes twice as much force to double the displacement of the top and so on. Once it's assembled they are quite strongly coupled; each part, such as the top or the sides, or the air in the box, affects the way the others respond. This produces a complex system, the output of which becomes impossible to predict beyond a certain point. So the first question is, how close to the 'required' tone do you have to get to claim 'success'?

I have tried several times to build 'matched pairs' of guitars, using more and more stringent controls. Each time I get a little closer, but so far they don't sound 'identical'. It is fairly easy for a practiced maker to match the response (as measured objectively) below, say, about 500 Hz, and with some care you can extent that an octave or so to around 1000Hz. Above that small local variations in the wood start to become more important. These will alter the sound at some frequency or another, and that becomes more pronounced as you go higher in pitch. That's the nature of strongly coupled systems. Since human hearing acuity peaks at around 3000Hz it may simply be impossible to duplicate the sound of a given instrument exactly, at least as long as you're working with wood.

Much of the 'signature' sound of a guitar comes from things like the size and shape; Dreads have a 'characteristic' sound that is unlike Jumbos, even though they're similar in size, and neither of those sounds like a 'parlor' guitar, let alone a classical or an arch top. When going for a particular sound any maker will start with the size and shape that's most likely to produce it. After that, it's matter of pushing things in the direction that's wanted.

An example of that is in how you treat top bracing. Let's confine this to steel string flat tops for now. For a punchy, bass heavy sound you'd tend to go to scalloped bracing, which (among other things) tends to maximize the amount of air the top can pump through the sound hole in the low range. Since there's only a limited amount of energy in the string to work with, this tends to bring with it a shorter sustain, although there are tweaks you can use for that, too. There's a reason, IMO, why Martin uses ebony bridges on the scalloped braced Dreads. For a player who wants a more 'balanced' sound with longer sustain, you'd move toward straight or even tapered bracing. There are probably a couple of dozen or more of these sorts of variables that an experienced luthier works with.

At this point we're looking at some general schemes. There are a number of ways to go from there to specific methods of determining where to take off a little bit of wood from one part or another to optimize the response. Dana Bourgeois has been generous in writing articles in the lutherie press and giving classes and workshops that describe his tap tuning methods. They're pretty subjective in some respects, but I will say that when I have used acoustic testing to 'track' what he does it makes perfect sense. That is, his method is rational and achieves consistent results that are physically sensible as far as they go. There are other resources, including a four-hour video I put out some years ago on Chladni tuning of steel string guitar tops.

And that's where we hit the wall. As I detailed above, given the nature of the system there may simply be no way to go from the behavior of individual assemblies, such as the top, back, and sides, to a detailed prediction of the final sound of the instrument. On one extreme I don't think anybody would go so far as to claim that the way the top, say, works has no effect on that final sound. We have to accept that the other extreme also exists: that there is no way to specify how to make a top of a particular piece of wood that will produce precisely this sound. What we all end up doing is devising some sort of empirical system that can get us 'arbitrarily close', and that's usually 'close enough'.

To get an idea of the level of technology that has been applied to this sort of problem, look up Martin Schleske. He makes 'tonal copies' of fine violins that come pretty close, using laser holography and laser Doppler interferometry to provide both dimensional and acoustic information on the target instrument. He holds both a Ph.D. in physics and a Masters rating in the German violin makers guild. He has said, on a violin maker's forum, that it's not possible, even in theory, to specify exactly what each part of a violin needs to do to produce a particular sound; all you can do is get as close as your skill and understanding will take you. In the end, there's always going to be some 'art' involved.

You're asking for certitude where there can be none.
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  #74  
Old 11-20-2017, 03:27 PM
BluesKing777 BluesKing777 is offline
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This Lowden Guitars workshop video is nice, the theme song is catchy and we see lots of hand doings...


https://www.youtube.com/watch?v=ZsC05WH7Hrk



BluesKing777.
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  #75  
Old 11-20-2017, 03:34 PM
stringjunky stringjunky is offline
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Originally Posted by BluesKing777 View Post
This Lowden Guitars workshop video is nice, the theme song is catchy and we see lots of hand doings...


https://www.youtube.com/watch?v=ZsC05WH7Hrk



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Lowden now have at least one CNC.
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