Archive | April, 2013

Zen and the art of guitar making (or how to find the right bracing arrangement for your guitar)

10 Apr
Variations of bracing layouts

Variations of bracing layouts

As I recall, my first guitar making teacher taught me three important lessons:

The first, upon telling him of my wish/desire/unaccountable urge to build guitars was to advise me, ‘It’s not easy. Don’t expect to make any money from it. At least for the first ten years, if ever.’  which so far has proved to be fairly true.

The second excellent piece of wisdom, somewhat took me by surprise when he said it, but in fact has a ring of truth. He said, ‘You know what building a guitar is like?’ I thought about it, considering all sorts of poetic analogies involving trees, women, love… ‘Building a guitar,’ he said, ‘is like going into battle.’

He didn’t go into it in any more detail, being a man of few words, but I see what he meant. First you need to make sure your tools (your weapons) are sharp – as sharp as they can be. If they’re not, you’ve lost from the start. Then, with a clear and focussed mind, you need to face your adversary (a piece of wood), evaluate its strengths and weaknesses, before engaging in battle. There may be blood. There may be tears, howls of rage. There may be defeat. You may have dreams of victory and glory, but in the final analysis you’ll be lucky to come away with an armistice – an agreement of peace.

OK, maybe that’s taking it all a bit far, but it’s the third pearl of wisdom that I wanted to talk about anyway. And it was ‘when you’ve build about a hundred guitars, you might start to understand how to do it.’

At the time we were talking about bracing the soundboard and that’s what I want to talk about now.

(The bracing, by the way, is thin bits of wood glued to the inside of the soundboard. This is what gives the soundboard its tension and determines the way the guitar will respond, feel, play and sound)

At the top of this page you’ll see a drawing I made of five different bracing patterns of a group of five individuals I am helping to build their first guitars. Since none of them have built guitars before, or studied guitar construction, there’s no reason why they should know anything about how to brace a guitar’s soundboard. I myself played guitar for about twenty years without ever being aware of this mysterious matrix pattern just below the surface of the guitar.

So I helped them design the layout that I think would best suit their guitar. Of course they all ask the questions ‘why would you do it like this and not like that?’ and ‘how will this effect the sound?’

Now, I thought I might sit down and write a lengthy analysis of why I decided some guitars would be better with 5 fan struts, some with 7. Why I might put closing bars at the bottom of some and not others. Why I would choose to or not to reinforce the bridge area, or put a diagonal bar. I hope they will all be good guitars that will reflect the personality of the maker and perform according to how they would like their guitar to perform.

Here’s an explanation of how I design the bracing for a guitar (this is not to say that you should do it this way) :

First I look at the shape of the guitar. How wide, how long, the curves.

Then I consider how I would like it to sound. How deep, how high, how quick, how round, how sharp, how smooth.

The I feel the soundboard (the thicknessing is also part of this meditation as is every other aspect of construction. Everything effects the sound, remember) how light, how springy. How does it flex? How does it sound when I tap it?

Then I clear my mind of all other considerations…

The guitar is a soul waiting to be born.

The design has been written in the stars. It is the genetic code. The fingerprint. The face, the voice.

And then gradually the pattern appears.

I imagine how the sound will travel across the plain of dry wood, how the thin bars will help it, direct it, give it focus, clarity, balance, strength, power, projection.

I draw them as I see them appear. Change one here and there until it looks like it’s meant to be. And then put them all in place.

That’s how I do it. Kind of intuition.

Of course experience helps.

That’s why I agree with my teacher when he said the thing about the hundred guitars. Until then, every guitar’s an experiment. Even after that it still is, for most makers.

Here though, as best I can, I will try to explain why I recommended the patterns drawn here:

Variations of bracing layouts

These are the qualities I would like these guitars to have (these are my predictions):

1. Tal. (simple, symetrical 7 fan-struts, closing bars at the ends. No bridge reinforcement.) Aim: A well balanced response with good focus and clarity, yet having an openness and freedom, lightness and playability to make it a fun and versatile instrument.

2. Oren, incidentally Tal’s brother. (7 fan struts, diagonal harmonic bar, bridge reinforcement, closing bars). Similar in many ways to Tal’s, yet with more focus, separation of bass and treble as well as individual notes. Perhaps a more demanding instrument in terms of playability – ie. it may prefer to be played one way that another, yet may offer rich rewards to the right player.

3. Ranan. (7 fan struts, short diagonal harmonic bar, Loch Ness monster bridge bar, open closing bars.) This should be an unusual guitar with deep bass response, while maintaining a quickness about the mids and trebles. An understated guitar when played gently, yet able to produce a powerful punch.

4. Alex. (5 symetrical fan struts all the way to the edges. No bridge reinforcement or closing bars) In many ways an old fashioned, traditional Spanish guitar, with an earthy quality, broad in range, versatile, strong, yet with unexpected subtlety.

5.  Nimrod (lots of diagonal lattice bracing – fairly light, a single harmonic bar above the soundhole (slightly different from in the picture)) A rather unusual sounding guitar with plenty of harmonics and overtones, very lively response with a quickness and lightness of touch.

Now don’t ask me to explain why I think all that might me the case. I might be completely wrong.

For some more scientific analysis of acoustic and bracing design you can look at these links:

http://www.danielbrauchli.com/Acoustic_Concepts.htm

http://www.guitarmasterworks.com/about-guitar-acoustics-101.html

http://www.ericbattenberg.com/school/ebattenberg_ME173_S09.pdf

http://dogwoodguitars.com/voicing-and-tap-tuning/

http://www.luthierforum.com/index.php?/topic/3275-acoustic-guitar-bracing-and-top-dimensions/

http://www.phys.unsw.edu.au/music/guitaracoustics/construction.html

…..etc….