Official Luthiers Forum!

Those of you who know me or are familiar with my work know that I like to experiment with different designs, non-traditional sound hole placement, and less frequently used tone woods. I often get asked how movement of the sound hole and changing the bracing affects the sound of a guitar. My answer is usually a bit hand-wavy and theoretical. No more. With my current project, I’m hoping to come up with a more concrete answer of the similarities and differences by building a practical example.

The plan is to build two similar, but quite different guitars. I want them both to be extremely lightweight and responsive instruments. Both will be made from butternut re-sawed from the same boards. Both will have Engelmann spruce tops from the same supplier. Both will be 000/OM sized bodies. Both will have a cutaway. Both will have the neck/body joint at the 12th fret. Both will have necks and fretboards of the same materials. One will be built with a center sound hole and traditional X bracing. The other will have multiple sound holes and be braced using an offset asymmetrical X bracing pattern.

I’ll post photos and updates here periodically, starting with the pics below. More frequent progress updates will be posted on Facebook (http://www.facebook.com/bounsallgutarworks). It should be an interesting experiment. Stay tuned.

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Andy
www.bounsallguitarworks.com

This looks like it will be fun to follow. The butternut grain looks cool.

What's the thinking behind the asymmetric x-braces? Is that a result of needing to thread between the small sound holes?

It looks like the guitar with the small sound holes will have some sort of larger neck block arrangement. How will that work?

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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

Kewlness. Will be watching for the butternut...

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"Act your age, not your shoe size" - Prince

Nice. I always build two at a time also. Just seems to make more sense in terms of tool/jig setup and what-not.

Many years ago there was a now defunct company on the west coast of the USA called Tacoma Guitars. They built some interesting guitars with paisley shaped sound holes in the upper bout and incorporated some novel ideas. I always liked the way those guitars sounded so the offset asymmetrical X bracing is my adaptation of how some of those guitars were built. Yes, it does work well with the multiple sound holes. I actually layout the bracing first and then adjust the sound holes to fit around them.

The large neck block on the drawing is a bit misleading perhaps. It’s really a normal sized neck block with an extension on top to support the end of the fretboard. Here’s a pic of what I mean, but it’s upside down. What looks like a “foot” in the pic goes directly beneath the soundboard.

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Andy
www.bounsallguitarworks.com

I once built two 'identical' guitars side by side. All the wood for these guitars was cut successively from the same log one right after the other. So they were about as close to identical as possible. A few things that id did not do back then was stiffness testing but I did measure everything to be the same width, height and so on. The braces were all measured the same and came from the same billet. The tops were the same, backs, sides and so on. Everything was built to be as close to the same as possible. I think the fret boards were the only things that were not from the same log.

In the end I ended up building two guitars that sounded different. They just end up having their own personality.

Of course what you are doing is different and may even be more practical in terms of learning something between the two designs. What might even be more valuable is building two pairs(4 guitars). That way you could compare the two designs together then compare each individual design with it's opposite and it's opposites opposite.

And how do you tell any difference which is due to the sound hole's/placement, and how much to the bracing?

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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.

Can’t...but I’m interested in the combination rather than each individually.

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Andy
www.bounsallguitarworks.com

The butternut is really pretty.

Interesting. Is the grain arrangement on the block for strength in bolting on the neck?

I've tried building 2 or 3 violins at the same time, but one always gets ahead, and I end up with 1! It always seems like a good idea. I need to follow through.

Maybe the next build.

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Why be normal?

I imagine you have made the total area of the (pretty) array of small holes to match a 'normal' soundhole...?

Dave

I like the part of the neck block the glues to the rim to have grain running vertically. If the rim was to split, the split wouldn’t propagate through the neck block. However, that’d mean the back would be glued to end grain, which I don’t like. So, I make the neck block with horizontal grain on the inner half. That gives the back some long grain to hang on to. Probably doesn’t make much of a difference, but I sleep better.



The single sound hole is 4” diameter. The total area of the multiple holes on the second guitar, if I did the math correctly, is about equal to a 3.6” hole. So...close, but not identical.

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Andy
www.bounsallguitarworks.com

I suspect what Ken was noticing was that you’ve managed to glue 3 pieces of wood in a way that ignores the different directions of differential shrinkage and swelling. It’s not a stable structure.


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Ok. That’s a fair enough opinion. That particular piece was for a guitar I built several years ago. It hasn’t proved to be an issue yet but I hear what you’re saying. Anyway, the photo was included here simply to illustrate what the ‘large neck block’ shown in the drawing was referring to.

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Andy
www.bounsallguitarworks.com

IMHO, your analysis is backwards. A split side is not likely to split into a block that is many times thicker. But the reverse surely happens....... the block splits, then the sides follow.
I would do a simple three-ply laminated block. I am not a fan of the vertical orientation.

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John

Thanks for your thoughts regarding neck block grain orientation, folks. Appreciate it but maybe that discussion could be taken to a new topic rather than derailing this thread.

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Andy
www.bounsallguitarworks.com

Hi Andy,
Interesting project -- it will be fun to see how it turns out.