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For all you experts out there on voicing, do you make changes to your classical bracing to voice the guitar? The only reason I ask is because most of the braces are so small. For example, on the 3 Hauser models I just braced, transverse brace #1 is only 1.5 mm tall, and all the finger braces are between 3.00 to 4.00 mm tall. The only braces that really have any "meat" on them are transverse brace 2 and 3, and these are only 12.5 and 13 mm tall by 6.5 and 7.0 mm wide. Those seem to be more for strength than tone. Is it possible to really shave the braces much more to voice the guitar?

Thanks!

John John Elshaw38895.7491666667

Hi John,

I'd like to provide my input, but I'm not clear on your terminology. For example, which transverse brace is #1? At 1.5mm tall, I'm thinking it's the bridge pad? If so, that's about right. If by "finger braces," you're referring to the fan braces, I'd say 3 to 4mm (0.118" to 0.157") is fine, unless you are thicknessing your top in the 2.3 to 3mm (0.090" to 0.118") range, the way Hauser did. His braces, according to a Jeff Elliott drawing I have, were quite shallow. But he left his tops quite a bit thicker than most other classical builders do.

Hauser also put a parabolic shape on his braces, rather than running them straight and scalloping the ends.

Your upper transverse braces (aka the tone bars), are just a bit on the thin side. I usually shoot for 5/16" wide by about 1/2" tall (8mm x 13mm).

I have built several guitars using the Torres/Hauser 7-fan pattern, and used the guidelines that Sloane showed in his book, Classic Guitar Construction. He specs out fan braces that are 1/4" wide by 1/8" tall (6mm x 3mm), and shaves the fan braces such that they are shaped to a triangle, cross-sectionally. He also specs out tone bars of the same dimension that I mention above, and shapes them to a parabolic cross section.

I have built one guitar that was as close to a Hauser as I could get it. I wasn't interested in it looking like a Hauser cosmetically, but I used the 1937 Ex-Segovia plantilla, and Elliott's drawings from a 1943 model. I also obtained a copy of the top measurements R. Brune made from the Ex-Segovia 1937 Hauser and thicknessed the top as close as I could to these specs. For woods, I used AAA grade Euro spruce and EIR (couldn't afford brazillion). The guitar came out well. It has taken a while to open up (because of its thick top, I presume), but it has a very nice tonal quality and good sustain.

The guitars I built before this one, using the Hauser plantilla but Sloan's guidelines, also came out well. It would be very difficult, I think, to judge which was better qualitatively.

Now, getting to your questions (at last), if a person is coming from the steel-string world, it is normal, I suspect, to think the guitar is braced too lightly. But this is the way good classicals have to be built. Given the fact that you're working on three Hauser-style classicals right now, I think it's safe to assume that you already know this very well.

Tom Blackshear, a well-respected builder of Rodriguez copies, has commented that often the very lightest touch of sanding is all that is required to adjust a classical's voice. Dunno how true this is. I've had to shave more than a tiny amount from the bracing on a couple of guitars to get the voice or responsiveness I was after. But to be fair, this was using a different bracing pattern from the Torres/Hauser 7-fan pattern. Often these adjustments can be done before the back has been put into place. I've learned from personal experience to shave braces down to where I think they're too light, and then just take a bit more off.

Best,

Michael

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Live to Play, Play to Live

I would tend to not touch the transverse braces (2&3) as they are for strength. As far as shaving the fan (finger) braces it all depends on what you are hearing.

You can take material off the top in areas as well and that can help as much or more than shaving braces when the braces are as small as they are on a classical. You thin towards the edges of the top while or thin the top mostly between the back of bridge area to the tail block. You need to hear what it is doing to the overall sound.

How are you voicing it? Are you using a specific harmonic frequency as some do or are you using chaldni glitter tuning or some other method?

In general if the guitar built light you will end up with a good sound but it takes both an ear or touch to know what to shave and how much wood to leave.

I used to build to the same general dimensions for bracing having sorted my bracing stock by deflection testing for consistency. I would get generally the same overall sound but some guitars would end up better than others.

Since hearing and seeing Alan Carruth do a workshop session on "glitter pattern" voicing at the 2003 ASIA symposium I have been doing glitter pattern voicing and it has given me much more refined, consistent results. I still shave by hand based on feel and sound before I do the glitter voicing but will refine once I have glitter tuned. The interesting thing is that is is not completely about what frequency each node vibrates at but more about the shape of the pattern as an indicator of how focused it is getting.

Alan has responded about it before so search the archives for voicing, it is very interesting. Having said that I enjoy just as much hearing Erwin Somogyi talk on voicing at last years symposium (I would love to go to his voicing class some day) as his approach is quite different but I see it as two sides of the same coin...both are working to the same goal, just getting there different ways.

Here is a pic of the bracing I am talking about. Transverse bar 1, 2, and 3 are ordered from the top down.
I've only built classicals but with all the talk of voicing by the steel-string builders around here, I was wondering if much could be done on a classical when so much of the bracing is already 'small'.

Michael... my sizes for the transverse and fan bracing come directly off a Hauser III model guitar. I think he makes a better sounding guitar than his dad or grand-dad, and those are the bracing sizes he uses. I'll let you know how it sounds as my last guitars were true to the 1937 Hauser plans by Brune.



Cheers!

John
John Elshaw38895.9353009259

John,

Looks nice. Do you peak your fan braces, leave them more-or-less rectangular, or do you put a parabolic cross-section to them? It's hard to tell from the photo.

I ask because, recently I played a friend's Alvarez Yairi, probably made back in the late 80s, that had this wonderful Spanish sound. I was quite surprised at just how great that guitar sounded. My friend builds guitars also and so we did the old inspection mirror thing. I was surprised to see that the seven fans were quite small and rectangular in cross section. It also had the angled cross brace (just below transverse brace #3) that many classical builders use.

Regarding that angled cross brace, I recall reading that one of the Spaniards likes to use it because it tends to eliminate voicing issues apparently associated with the more traditional 7-fan pattern. I have a theory as to why this is. By installing an angled cross brace, the 7 fan braces are no longer quite so symmetrical -- each has its own length, thus its own inherent resonant frequency, the shorter ones being higher than the longer ones. So it would stand to reason that less work on voicing to bring out the highs, for example, would be necessary. I have yet to build a classical using an angled cross brace, so it is still speculation on my part, but I still think it makes sense.

Best,

Michael

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Live to Play, Play to Live

Looks great John. Nice and clean. I think that in general tuning the top in classicals refers to tap tuning and thicknesing the actual top. There are a wide variety of bracing schemes and thickness'. All of them have thicker or taller fans near the center and lighter fans near the outside edges. But I believe that in general the tap tuning comes first, prior to bracing. Top thicknessing also follows this general trend. Thicker under the bridge and thin out toward the guitars edge. Have you gotten a chance to read "Making Master Guitars" by Roy Courtnall? It is a great read because it analyzes each master's approach and gives specs on their most successful guitars.

Hey Guys-

Check out American Lutherie #56 Winter 1998. Jeff Elliott explains at length his ideas about the effects of bracing and wood selection on tone for Spanish guitars. It's an informative article - he holds nothing back at all. He gives away all his "secrets" about how he builds the Spanish guitar. It's well worth the $10 for a back issue from GAL. I'm sure most builders are aware of this article but for those that aren't, this is worth checking out.

Happy building-John Lewis38896.5990393519

_________________
John Lewis
Wannabe builder owned by 2 crazy dachshunds

A pic of my Torres based classical showing fan bracing. All braces are shaped to a peak but no scalloping. Transverse braces are probably a bit on the heavy side but top is very thin (0.085 - 0.075" in places).


kiwigeo38900.1748958333

The bracing on a classical is indeed lighter than that on a steel string, because bracing is mostly there to resist tension, and the tension is lower. You still voice by working on the bracing, you just take lighter cuts!

The other thing is that it's harder to get the sound right on a classical than on a steel string. Partly it's because there's less power to work with, and partly because the steel strings have a lot more high-end energy, which helps them 'cut' better. There's just less leeway for mistakes on a classical.

For the most part I can get them pretty much 'right' by looking at the 'glitter patterns', although once in a while something unexpected will come up. Usually those are good 'learning experiences', but they can be embarrasing when the guitar isn't what the customer wanted.

I suspect the same thing is true for any system that somebody has used for a long time, particularly if they've kept good records. Ultimately you learn what works and what doesn't.

The voicing workshop with Ervin at the last ASIA was fun. As you say, he and I take different approaches, but ultimately we're starting from the same basic designs and try to end up with 'good' guitars, so the end results are bound to be similar.

Here's a more-or-less radial bracing pattern that I've developed.



It's symmetrical, but the fans are six different lengths, which I feel adds balance across the spectrum. With my last few builds using this pattern, I've shaped the fans parabolically. Also, the lower transverse brace is shaped as an asymmetric parabola, with the peak just under where the 1st string will be. The tone bars contact the top in the center, for slightly more than the diameter of the soundhole, and at the very edges. This allows the upper bout to vibrate easier. I can't say doing so increases the volume particularly, but it does seem to add a fullness to the overall sound.

Best,

Michael

_________________
Live to Play, Play to Live

[QUOTE=Michael McBroom] Here's a more-or-less radial bracing pattern that I've developed.
[/QUOTE]
Very interesting! Does the lower transverse run directly under the saddle? If so, did you notice a more pronounced bass when you first started doing this? It's a result suggested by Alan Carruth.

Carlton,

Yes, the lower transverse brace runs directly under the saddle.

I recall Alan mentioning the transverse brace in a thread several months ago. By that point, I had already built a few classicals using this pattern.

One comment Alan made that really struck me was that it seems that classicals with an under-the-saddle transverse brace can be played harder before the sound, um, for lack of a better term, "craps out." I have known for a long time that a classical's volume will peak at a certain point, and no matter how much harder I strike the strings, it doesn't give out any more volume, instead it distorts or craps out or whatever.

Just a few days before Alan made this post, I was playing one of my guitars -- the first one I built using this pattern, and -- okay, might as well admit it -- I got a little ticked at something my wife said to me, and really bore into the guitar out of anger and frustration. The results amazed me. The guitar just got louder and louder. I stopped playing, just staring down at it, my wife's remark completely forgotten.

And then, a few days later, Alan posts that comment, and things clicked.

Regarding the possible increase in bass response, I can't honestly say that this has been demonstrated in my builds. The guitar I mention above was built sort of using the Hauser template, with quite shallow sides. I find that shallower sides improves separation, but can results in some loss of bass response. I would describe the basses on this guitar as loud and clear, and resonant, but not as full as one might hear on deeper bodied guitars. I have built other guitars using this pattern with deeper bodies, but I still dunno if I would make the claim that they have more bass response than others with similar body depths.

Best,

Michael

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Live to Play, Play to Live

Michael,

Where are you sourcing the extra wide ebony for the fretboards on your
10 strings?kiwigeo38900.8385532407

Martin,

For the first two I built, I scored some extra wide pieces from Grant Goltz, who drops in here at OLF from time to time. Grant has been very busy with other projects for the past several months, so I decided to try joining fretboards, since he was unavailable as a source. That worked quite well, actually. I shoot them with my #6 Stanley to get a good tight seam and then epoxy them together. The seam shows somewhat because of the grain, but I dye the fbs, so it is virtually undetectable. The last four 10-strings I've built have joined fbs, and I have another five on order, for which the fbs have already been joined and thicknessed.

Incidentally, the hard part has been finding bone nuts and saddles for 10-strings, and to a lesser extent, long bridges.

I've been using Corian for nuts and saddles, and I think it actually works pretty well, although it is a bit soft. Good density though. But then I found a source for processed bone. There's a place local to me -- Texas Knife Supply -- that sells camel bone knife handles that are about 5" long and are wide and thick enough for saddles and nuts. I bought a set of handles recently from them, and got enough out of the two pieces for nuts and saddles for two 10-strings, plus some left over for tie block inlays. I've found that camel bone is comparable in both hardness and density to cow bone. The last 10-string I built, I used camel bone for the nut and saddle. Dunno if the sound was any better than Corian, though.

Edd (don't recall the last name, but he sells EIR sets) sells 9.5" long EIR blanks for cheap. A few weeks ago, I bought fifty from him. Ought to hold me for a while.

Best,

Michael

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Live to Play, Play to Live

[QUOTE=Michael McBroom] Carlton,

Yes, the lower transverse brace runs directly under the saddle.
[/QUOTE]
Thanks for the info, Michael. Now that you mention it, I remember what Alan had said about the added dynamic range. I, too, have always been bothered by the harshness and distortion of overdriven tops built in the typical "Spanish" style. It sounds like you've found a solution to the problem. Cool!

In the prior post I'm pretty sure I was talking about something like a 'Bouchet' brace, which more or less ends at the ends of the bridge. Michael's lower transverse ins more like a Kasha 'TT' bar, which adds a lot of stiffness outboard of the bridge ends, and thereby works differently from the Bouchet.

Alan Carruth / Luthier

Alan,

Yes, you were talking about a Bouchet brace. I had heard of the Bouchet transverse brace when I worked out the above design, but I hadn't seen an example prior. Then, after discussing this design with a friend, he sent me a copy of a drawing of a Bouchet braced top. This is what he sent me:



True, the transverse brace does not extend to the edges of the soundboard, but almost. I cannot make any claim regarding the accuracy of the drawing, however, since I don't know where it came from.


Best,

Michael
Michael McBroom38901.981875

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Live to Play, Play to Live

[QUOTE=Alan Carruth] In the prior post I'm pretty sure I was talking about something like a 'Bouchet' brace, which more or less ends at the ends of the bridge. [/QUOTE]
Thanks for the clarification, Alan. So much to learn--so little time!

I guess there are a lot of versions of the 'Bouchet' brace: I wonder what the man himself used?