Official Luthiers Forum!

"I'm adding chambers to my solid-body to get a little more resonance."

I think you need to differentiate between the liners and the sides when it comes to mass and stiffness.
You can have heavy stiff liners without having heavy or stiff sides.

And stiff sides can be produced by adding copious numbers of side braces with little weight added, and this will tend to raise the air resonance.

The use of solid liners between soundboard and sides provides an impedance mismatch between soundboard and sides to retain more energy in the soundboard. Think in terms of a ball rolling and hitting a solid wall and bouncing back, as opposed to hitting a hay bale and stopping.

Adding extra mass to the side however, produces an effect through conservation of momentum.

Myth: "instrument making is the highest form of wood working".
There are certainly many types of wood construction that are more demanding and require more skill than constructing a box with strings. I would however add that there is a certain undefinable element that makes a great guitar.

like what?

Check out Paul Schurch's work
http://www.schurchwoodwork.com/portfolio1/index.html
http://veneerartist.com/schurch-portfolio/

-jd

This one is a good one. A customer brought in this clipped out magazine article a while ago. It's been riding around the shop for a while. Not sure the mag but it could be Popular Science or the like. The article is called A "Just Right" Guitar. The caption under the title is " A 68mm thick guitar produces the best quality tone" I won't be typing the whole thing but it would seem an electrical engineer named Kazutaka Itako from Japan has played guitar since he was 6. His brother is also an electrical engineer works as a "guitar fabricator". (this is all quoted). They tested one variable in guitar construction, the body depth. They constructed 4 near identical guitars with body depths ranging from 58 to 98 mm. They tested the tonal qualities and harmonics while a performer played open strings with 2 different strumming styles, using both objective and subjective (Alan, what does that mean? ha ha) measures. they used an oscilloscope to measure harmonics. The 68 mmm guitar had the richest combination of harmonics and 6 of the 9 listeners that were rating the tone quality voted for the 68mm guitar for best sound quality. The brothers are now working on how the size of the sound hole alters the guitars tone. After that, they plan to determine whether a synthetic materiel such as fibreglass ( has that been done? )could be used to make instruments as "sonorous" as wood versions, which are apparently "time consuming and finicky to make". The brothers goal is to identify the ideal dimensions and materials for a high quality subprofessional instrument which would allow more amateur strummers to buy good guitars at more affordable prices.

So there you have it. I for one am happy to go into the New Year with one less variable nailed down. 68 mm. However, they didn't say if it was a classical or SS.

Best of the Season everyone and I hope y'all have a Merry Christmas.

Cheers,
Danny

Measure thou sixty eight, no more, no less. Sixty eight shall be the number thou shalt measure, and the number of the measuring shall be sixty eight. Sixty nine shalt thou not measure, neither measure thou sixty seven, excepting that thou then proceed to measure sixty eight. Seventy is right out.

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

How about this - http://www.youtube.com/embed/MKikHxKeodA?rel=0


Cheers,

Shane

A skilled builder can make any wood sound like any other wood...

Wiki-



Looks not bad to me, although the tone's a bit lacking a certain "je ne sais quois".

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Clay S. wrote:
There are certainly many types of wood construction that are more demanding and require more skill than constructing a box with strings.


like what?


Boat building, barrel making,,building wooden air frames, wooden clock making, some types of cabinetry (bombe chests?) and wood carvings, some timber frames, etc. Not to say building a good guitar doesn't take skill, but there are plenty of other woodworking crafts that require just as much or more skill. Perhaps it is because our constructions speak and breathe that we give some special merit to their construction.

Maybe even violin making?

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

One of my favorites..

The Spanish heel neck joint is considered the most highly developed neck joint in guitar construction. It is significantly more complex than a glued neck, but the sonic benefits are worth the effort.

The vibration is not interrupted by the Spanish heel, there are no or hardly audible nodes. Another advantage for sound transmission is, that the material of the neck-body junction can be kept very small.

Yep.Yep.

Gentlemen !!! It seems at this point we should wander into the most difficult possible guitar building there is . Its a subject that everyone in luthery avoids because of the huge technical difficulty . Yes , you all know what I mean ..

AIR GUITAR CONSTRUCTION !

_________________
The Shallower the depth of the stream , The Louder the Babble !
The Taking Of Offense Is the Life Course Of The Stupid One !
Wanna Leave a Better Planet for our Kids? How about Working on BETTER KIDS for our Planet !
Forgiveness is the ability to accept an apology that you will probably NEVER GET
The truth will set you free , But FIRST, it will probably Piss you Off !
Creativity is allowing yourself to make Mistakes, Art is knowing which ones to Keep !
The Saddest thing anyone can do , is push a Loyal Person to the point that they Dont Care Anymore
Never met a STRONG person who had an EASY past !
http://wiksnwudwerks.blogspot.com/
http://www.facebook.com/groups/GatewayA ... rAssembly/

Jeff Highland wrote:
"The use of solid liners between soundboard and sides provides an impedance mismatch between soundboard and sides to retain more energy in the soundboard."

Because of the relatively thin plates guitars already have a much larger impedance mismatch at the edge than violins. You can see this in the fact that very few of the 'wood' resonant modes of the guitar have node lines that run off the edge. One of the main resonant modes of the violin has node lines that run around the box like the seam on a baseball. There are two node lines that run along the length of the top, roughly from the wide part of the upper bout to the wide part of the lower. They then run down the ribs, and across the back, with a kink in toward the middle. This is an acoustically important mode, and it works the way it does because the top and back are relatively thick, and the liners and ribs are light. We're working with almost the opposite setup.

Of course some energy does 'leak' from the top to the sides of the guitar at high frequencies. Impedance is frequency related, and making the edges stiffer or heavier will alter the relationship, and change the pitch at which the energy leakage occurs, so it's likely to alter the sound. But it doesn't seem to change the lower order modes much.

Danny V wrote:
" I for one am happy to go into the New Year with one less variable nailed down. 68 mm."

Yup, a real relief alright. I do sort of wonder how they controlled all the variables so well that they could draw valid conclusions from such a small sample. Given the variation in sound you'll get from two 'identical' guitars I'd think you'd need to build eight or ten of each body depth to be able to say much with any confidence. That's one of the problems with doing experiments with guitars.

Years ago Fred Dickens, a researcher as Bell Labs who built Classicals in his spare time, looked into the effect of body depth on sound. He made one that was about 6" deep, and cut it down an inch at a time until it was to shallow to work. He didn't tell me about any listening tests; he was more interested in influence on the 'main air' mode pitch. Going from 6" deep to around 2" raised the main air pitch by about 7%; a little more than a semitone. So much for 'a deeper body has a lower air mode'. I'd say this was a pretty valid test because hed was only looking for a limited amount of information, and the top, back, and neck, and the wood in the sides, was the same all through.

Clay S gave examples of crafts that require more skill than guitar making, in his opinion.
"Boat building, barrel making,,building wooden air frames, wooden clock making, some types of cabinetry (bombe chests?) and wood carvings, some timber frames, etc. "

I had a student once who used to teach wooden boat building: he was not much better at precision work than the framing carpenters.
An article on the annual Oskosh EAA fly-in of homebuilt aircraft I saw once in an airplane magazine talked about the 'luthier-like' workmanship.

When I was taking my violin making classes I brought down a small lap harp, based loosely on the 'Queen Mary', to show the other students. One of them, who was also a student at the Mittenwald school, and already a pretty good violin maker, thought she'd like to try making one, so I was describing the process over that evening, drawing pictures on the napkins at the restaurant. A small one will carry 900 pounds or so of tension, so everything has to fit tightly for it to be stable. Because it's a triangle the lengths and angles all have to be cut exactly: there's little leeway for adjustment. To top it off, the strings come off one side of the arm, and run down in the same plane to the center of the soundboard. The arm is off center, and the pillar has to run from the center of the soundboard at the bottom to the arm at the top, so it's a bit cockeyed. The head joint at the top of the pillar takes a lot of torque, so I use a deep mortise and tenon, cut on a compound angle. If you do it right, you can put the harp together without gluing the joints; they'll be held by string tension. I got about halfway through telling her how to set up and cut the joints and she said: "It's too complicated for me".

It's my opinion that almost every well developed craft gets to be pretty complicated, and there's not a lot of difference in the degree of difficulty. Each craft, of course, presents its own challenges, and some people find one harder than another. I make both, and I don't find making a violin to be more difficult than making a guitar; it's just different. I'm assured by my cabinet making friends that I could hand cut the dovetails for a Colonial highboy, but it looks pretty intimidating to me. I suppose they're right. Solzenitson said, in 'One day in the life of Ivan Denisovitch' that once you've picked up three crafts you can learn a dozen more.

With all that said, there's a local gunsmith who makes Pennsylvania/Kentucky rifles that are amazing. I don't think, at my age, I could hope to reach that level in that craft.

I've heard it told that Brazilian air is especially good for the back and sides.

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

Woodworking is only part of making great guitars.

Where many of the disciplines listed above include engineering and building in great strength Lutherie is at times an exercise in learning where the failure point is and then backing off this point slightly... To woodworkers strength for the intended function is pretty important for Luthiers we also want the strength but over building is often rewarded with a lower level of satisfaction...

Some approach Lutherie as a woodworking project. Luthiers approach guitar building with woodworking being important but so too is a high level of understanding of things such as voicing, fret work, set-up, and...... that all important and supremely subjective subject..... tone.

Just as all folks are unique so may be their motivation to pursue Lutherie. Again to some it's a woodworking project, a way to use that nice bandsaw and further justification to exercise one's passion for beautiful wood. To Luthiers the woodworking is important but not the primary goal - the goal to them is crafting superb sounding AND playing tools for musicians.

A barrel does not have a soul..... a guitar built by a highly skilled Luthier may....

Romantic notions once again from me here..... perhaps. Someone also once said that you have to be a good person to make great guitars, this was TJ Thompson who said this in a NPR interview.

I tend to agree with him....

A barrel does not have a soul.....

Tell that to a bottle of scotch!

How true Ed, how very true!

It certainly has a spirit. Badum bum

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

Myth: "instrument making is the highest form of wood working".

"Woodworking is only part of making great guitars."

I agree with the second statement. The woodworking part of guitarmaking is secondary to many other facets of the craft. I won't argue whether guitarmaking takes more or less skill than those other crafts mentioned, but considering the woodworking aspect only I wouldn't put it at the top of the list.

"I had a student once who used to teach wooden boat building: he was not much better at precision work than the framing carpenters.
An article on the annual Oskosh EAA fly-in of homebuilt aircraft I saw once in an airplane magazine talked about the 'luthier-like' workmanship."

As with guitarmakers, some boatbuilders are Hacks. I can see where a writer could draw the analogy between spruce spared aircraft and lutherie, and be complementary to both.

It certainly has a spirit. Badum bum

Nice!

Don't think it has been mentioned yet and am surprised no one has suggested it. "Dovetail necks make guitars that sound better compared to guitars with tongue and mortise necks". Maybe everyone thinks this is true................???
Tom

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A person who has never made a mistake has never made anything!!!

And of course Alaskan air for the top !

_________________
The Shallower the depth of the stream , The Louder the Babble !
The Taking Of Offense Is the Life Course Of The Stupid One !
Wanna Leave a Better Planet for our Kids? How about Working on BETTER KIDS for our Planet !
Forgiveness is the ability to accept an apology that you will probably NEVER GET
The truth will set you free , But FIRST, it will probably Piss you Off !
Creativity is allowing yourself to make Mistakes, Art is knowing which ones to Keep !
The Saddest thing anyone can do , is push a Loyal Person to the point that they Dont Care Anymore
Never met a STRONG person who had an EASY past !
http://wiksnwudwerks.blogspot.com/
http://www.facebook.com/groups/GatewayA ... rAssembly/

Funny, I was just watching the Martin Guitar factory tour video on YouTube https://www.youtube.com/watch?v=lxR_cvJoci8 and at 50:34 CF Martin IV actually says effectively this very thing......

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