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I don't know anything about flat, or mostly flat guitar backs and bellies. The bracing mystifies me. Not so much the fan bracing, and diagonal bracing; I get that they are for sound; but the very tall cross bracing especially above and below the sound hole. They all seem outrageously tall. It seems like they break the top into 3 distinct parts. Do they?

Is there any book or books you like that can shed some light? Yes, I know that it is mostly what the maker has decided works for them; and some might be considered gospel truth. But what is Truth?

Planning out the small baroque, tuned like a Terz, I see that this Dutch guy did his back and belly very thin, dead flat, and no linings. How he did the belly without linings I don't know. It seems they have about 66 lbs or so of tension on them total. This shorter one would use the same strings I would assume, and the tension would be the same?

Not knowing any better, it seems that if the belly was just curved some, radially east to west, by cutting the ribs down some, the stiffness would rise. The Cedar is very stiff lengthwise, but weak crossgrain. On the back, planing the ribs to a slight arch to give the back a north/south curve would make it stiffer too. It would still LOOK flat, until you put a yardstick on it.

Would these things block much of the resonance that the dead flat plates give? The curve on the belly would allow a conical curved fingerboard. I know it's heresy, but I'm not worried about that. I'm thinking about playing it.

It will just be a little critter. About the size of the 5 string viola, but deeper and with a longer neck. That one is the best thing I've done so far. It has a seal coat on it now. I took my time prepping it.

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This guy kinda knows what he’s talking about.. :0)

Get it half off if you have Stew-max

https://www.stewmac.com/How-To/Books/Gu ... ition.html

Sidebar: I still can't get over that books are half off with the stew-max thing. They can't even be breaking even on those books can they?

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Best books out there I feel...

Hi Ken,
The romantic guitars I have worked on have had linings of similar dimensions as you would find in a violin. These instruments were gut strung originally, and to my ears sound best with gut stringing.
One reason for the tall bracing above and below the soundhole is - because - of the large soundhole. The area between the bridge and soundhole tends to collapse if no reinforcement is used. Likewise the area between the soundhole and neck block tends to split and pull forward if unreinforced with bracing.
You can arch the soundboard if you want. It will add some stiffness and in my experience seems to reduce bass response (of which you won't have a lot anyway). You don't need to curve the fingerboard to match, just as you don't need to curve the soundboard to match a curved fingerboard. It is the bridge saddle that follows the fingerboard in a general fashion (but only somewhat so).
It looks like you are taking on a fun project. If you arch the plates and fingerboard very much people might mistake it for a "Russian cornerless violin" viola.

Clay, thanks for that. I see now that 35% or more of the length from end to end is gone with a sound hole. The f holes on a violin serve to "free" the movement up and down, but the length is continual for the entire length. On a violin 40% of the middle is solid, end to end. They are exactly opposite.

Yeah, I'm not worried about bass response. The low note will be about a fifth higher, but at the same time the high note will only be about to the body of a standard guitar; so there is less frequency range involved. The arch I put in wouldn't be much, probably not more than 1/8-1/4" in the lower bout, The cedar is very well quartered, even silky; that's why I only ended up with 2 small pieces! If I would have been able to pick from the pile, I would have more.

Tapping thin wood, (it's still too thick at 3-3.5 mm.) is different. It can give very low tones. This piece right now rings at 196 or so, (well you can get it to ring at just about anything, but 196 is strong and common) but if you tap on the edge you can hear 50 Hz. I don't think low will be a problem. Yeah, there was the problem of narrow boards and knots too.

I was planning on using thin linings. (2 mm or so) Without them, how would a binding work? I have ideas on that too. And gut strings too. I'll probably even do the tied frets; that will be something different.

I don't know what I'll do about books. I don't want to jump on the bandwagon of someones 'religion.' I'm not religious at all. I've written a daily devotional blog for 8 years, but I'm not religious. I don't even attend a church. So I'd like to see the different ideas, and then probably come up with my own. That's just the way that I am. If a book just presented the different options, and the reading, it would be great. I don't use computers to find this and that mode on a violin. I use it to generate tones to hear what the notes are, just as a point of reference, and to get something that I can keep track of if I REMEMBER TO KEEP NOTES. That's what the thick notebook I bought is for! I guess I'm looking more for Good sound, and not a specific sound. Why would you want them to be the same?

This will be the first test mule. Class begins.

Ken

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Thanks for the reminder. I went ahead and pulled the trigger before the deal disappeared.

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Joe Beaver
Maker of Sawdust

Ok, I see that it is what I'm looking for. Convincing my wife that I need a $200 set of books? Maybe in June when I turn 65 and don't have to pay for my health insurance. I NEVER think about money. But I am not an island. I am frugal too, but never think about money.

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A book you might be interested in that won't break the bank:

https://www.amazon.com/Fundamentals-Mus ... 048626484X

Benade writes about vibrations in flat plates among many other things. He deals with fiddles some too. It covers a lot of ground for $10.

I had that book for years. It fell apart from use.

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Mine fell apart also. I bought another copy this year. I have a few instrument building books, and have learned something from all of them, but nothing so enlightening that I achieved lutherie nirvana. I'm not sure any book can do that, and have seen a few expensive tomes touted as manna from the Master, and then later cast aside as spurious and incomplete.
I haven't absorbed everything Mr. Benade's book has to offer, so for now I'll keep pecking away at it.

+1 for Benade. I loaned mine out to somebody who claims they never saw it, and need to get another copy.

There are several approaches to getting the plates 'right'. The one I use is a 'tech' version of 'tap tone tuning', called 'Chladni pattern' tuning. It makes the tap tone resonances visible, and gives exact frequency readings on them. I wrote a series of articles on this in 'American Lutherie' back in '91-'92, and they're available in the 'Big Red Book' series from the GAL. I'll note that there is no simple way to relate the pitches of the tap tones/Chladni patterns to the resonant pitches of the assembled instrument, which are the ones that really matter. It's also hard to 'prove' that this method really works: these things are just to darn complicated. I do have some evidence that getting 'good' looking patterns, which correlates well with having tap tones that are 'clear' and 'sustained' (in other words, have 'high Q values') results in instruments that sound better to more people.

This approach does require some equipment to drive the resonances of the plates and give the frequencies. I've been using a hardware signal generator for years for this, but it can be hard to find one that does just what we need. Recently a friend of mine wrote an Android app, called 'Luthier Lab' that includes a signal generator. All you need on top of that is a power amp that puts out 12W-15W, and a few other little things, and you're in business. The app has lots of other useful features as well, such as a module that can record a sound, such as a tap on the guitar, and analyse the spectrum. He built in drawing tools, a fret scale calculator that can do multiscale fretboards, and lots of other stuff. The best thing about it is that he decided that there was no prospect of making any money on it, and put it out for free. You should be able to turn it up with a search.

As long as we're talking about free stuff, look up "Acoustics for Violin and Guitar Makers', 4th edition, by Erik Jansson. It's available for download free from the Swedish Technical Institute web site:
http://www.speech.kth.se/music/acviguit4
You'll need to download the chapters as .pdf files. It's old information, similar in vintage to Benade, but still good and still very useful. It also has a ink to a sound recording and analysis program called 'Wavesurfer' that has some nice features.

That should get you started.

The way I've been doing this is something like the area tuning method of Keith Hill. First I get them down to some starting point of weight and tap tone that suggests that it is still stiff enough, and not outrageously heavy, and then glue it on the ribs or clamp on a.board that is cut away. Then I tap and thin the places that are higher pitched in an area that is blocked off with my other hand. I don't worry about actual pitches.

I haven't tried the pattern thing, but a carved top is FAR different from a flat guitar bel!y or back. Even tones might be everywhere on them. It worked on the arch top.

I'll look at the Swedish link too. Thanks.

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2mm linings should be fine for a nylon string guitar, as long as you're only using a single veneer line for purfling, or the soundboard is thick enough that the purfling channel doesn't cut all the way through it. Otherwise you need the linings to extend a couple mm farther in than the purfling so it doesn't fall apart while you're working on it.

And yes, the tall cross braces basically define the active area of the soundboard. Here's an old thread where I wrote my thoughts on the matter: http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=47103

If you believe the guitar would sound better if the whole soundboard is able to vibrate, then try the flying buttress design (carbon fiber rods running from the headblock near the soundboard to the ribs near the second back brace), with cantilever fingerboard extension, and probably put the soundhole somewhere other than right in the middle.

My plan right now is to have 1.5 mm wide, BWB bindings, so about the same width as the ribs, maybe a hair wider. That makes the binding easy if you don't have, or want, a router. The main thing then is to not taper them until a ways past the depth of the binding. That's were good plans come in. 2 mm linings are what I put on the Arch top; just for gluing. I think the ribs have something to do with the sound, even if it is just allowing the back and belly to flex easier at the edges. Even the neck bends in certain modes. I could easily be wrong.

I have seen some guitars with different sound hole placements, and ports all over the place. I haven't thought about that yet; for a more or less true Baroque copy, I wouldn't do it. For something contemporary? Why not. But it would have to look good too. On a classical, I'm not sure that THEY would let you get away with it.

Bracing seems to be a wide open area. Nothing at al that is agreed upon. I'll play with that when I get there.

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Hi Ken,
On a lot of the early guitars the binding is only as deep as the thickness of the top and about the same width as the thickness of the side. The linings tend to be more like those of a violin family instrument - maybe about the size of a viola's.

There are always outliers, but there is a vast consensus that Martin/Gibson style X-bracing works very well. Experiments are usually educational but very seldom successful, especially if you are new at this.

'Flat' braced plates work a lot differently from arched ones. In a sense, flat plates do with bracing what arched ones do with arching and graduation. The typical resonant modes are different to some extent. OTOH, in both cases it seems that the thing you're trying to do is avoid messing up. You don't so much gain points for doing things right as lose point for doing things wrong. The trick is that what's 'right' for one top can be 'wrong' for another, and you have to come up with some way of figuring out what's 'right' in this case.

The Gore/Gillet books are anything but religion. It's Physics and engineering with even a bit of biology to boot. The second volume is the one that shows you a method for building a guitar. But the first one is all the information you would ever need to know what you are doing when you are assembling it regardless of what method you choose to do so with.

As for linings and purfling, with small linings you can just rout down half the thickness of the top and install the purfling so that the top still has good attachment to the linings.

Last night I was looking on my Kindle Fire for how to make a baroque neck. I've made one, and the Arch top has a vee notched head, but I want to see the point right at the nut. Didn't find anything, but I heard some baroque guitars. Some were really nice sounding. Some were more trebly, but still nice. Others leaned toward rubber bands. Is it the low end response that fills up the sound, and makes it richer? Then I heard this, a Vilhuela. This thing sounds great. It really is the predecessor of the Spanish Guitar. Can't find much about them. This one is amazing. Someone commented that the playing was too robotic. Really?

Is there any consensus on what causes the rubber band sound, and how to avoid it?

Has anyone EVER seen spruce? as beautiful as that?

https://youtu.be/duHMeCndpjo

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I suspect that a lot of the rubber band sound comes from having strings that are too slack relative to the load they could take. I learned a lot about this sort of thing back when I was making small harps. With those a good set of strings will make almost any harp sound good, while a bad set of strings will ruin the best built harp. You end up designing the strings first, and then building the instrument around that. Those 'rubber bandy' instruments would probably sound a lot better with lighter strings tuned to a higher pitch, to keep the total tension the same but with the strings closer to their ultimate load.

The Lousi Milan stuff on the old Baroque guitars sounds fantastic. I could listen to that stuff being played all day. I've been wanting to build a guitar like that for some time. I have a few old guitars in now for restoration. One is a Viennese guitar of unknown origin but probably early 1800's. It's a simple little thing that produces an amazing loud tone. The back braces on this thing are almost a full inch tall and very arched. The top is arched too and the fretboard floats freely over it. The other two are early Ashborn guitars and the neck join on these guitars are thing of beauty. Incredible workmanship. I think the baroque guitars had necks like these Ashborn's where a simple neck shaft of chestnut or butternut that is carved and then laminated with rosewood.

That figuring in spruce is known as Hazel Fichte - a.k.a. "Bear Claw" figure. When it covers the entire piece it is desirable, If only small amounts are present it is less desirable.

Hi John,
Here is an article on Ashborn guitars you may or may not have seen:

https://www.vintageguitar.com/3298/james-ashborn/

Thanks, good article. They mentioned the tuners in the article. He apparently made everything there and these ones have the original tuners and they are really cool.

It seems that antique baroques have much longer scale lengths. Maybe around 700 mms in E, the normal 640 for F or F sharp, and 600 for G. Maybe that's why some are strung up wrong.

Edit maybe some of that is taken away with A 415?

Planning mode in the winter. The basement is too cold for.me.

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