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In my very limited experience with tonewoods (guitar and violin) I've tried to develop an ear and method for wood tones. Read and watched lots too, for what its worth. I distinctly remember in a video, Bob Collings bending and tapping a top wood (which seems very flexible) and immediately dismissing it as "student" quality and asking who accepted that piece.

With my current build I noticed my top wood after joining, was very dull and flimsy. (the joint was perfect, of course! ) But I got to taxing my memory and knowledge as to how to make the best of this. Leave it on the thick side? Thin it down a little extra? Heavier bracing...or less?

The question is: how much can you really correct a dull piece of wood? Do you thickness, brace, and re-tap...or are we just trying to change a tiger's stripes with our techniques? Is it just best to put it in the student pile or kindling bin and get a new top?

After learning a process for testing top wood based on modulus, density/sq. inch, speed of sound, etc and hearing the results in multiple guitars using higher and lower scoring tops, I have concluded that great tone comes from great wood, and average wood produces average tone. So many variables here including the fact that we all have our own ears for what great tone is. And, there are many approaches to getting consistent great tone. In my experience and in the experience of those I learned voicing and tuning from, you can't get superior tone from wood that isn't capable of producing it, no matter what you do with braces, thickness, etc. I would add that a verifiable testing procedure based on science and physics is much more accurate (and consistent) than subjective flex and tap methods.

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It will probably be alright.

Hi David and great question!

Many newer builders are admittedly at a disadvantage in a number of ways including wood/top selection. Top selection to some builders is so very important that they can spend an entire day on top selection in classes that they hold - example Somogyi.

For we mere mortal builders who may not live in the lands of tonewood suppliers we kind of sort of have to take what they send us and try to make it work. When we have been doing this a bit longer we usually have multiple choices of less than stellar tops to choose from making it not easier mind you but seemingly so as we get to at least select the best of the worst....

A dull top in an of itself will not necessarily a bad guitar make. A skilled builder (and bracer) can exploit what they have to work with and try to get the very most out of it. There is also a bit of a mystery that happens to and with builders although some won't admit it... We don't really know what we are going to have until the fat lady sings and the box is closed, the guitar finished, in someone's lap and we hear what she sounds like. Sure lots of builders will claim that they have enough control over the process to know in advance if they have a good one or a not-so-good-one.... I won't make this claim, it's always a mystery to me for the most part. I have my suspicions but I have also walked the earth long enough to know that being surprised for better or worse is just part of Lutherie... at least it is for me.

So with that dull top, what to do you ask. By around number 6 I wanted to get deeper into voicing and see if it's snake oil or the mark of the master.... so-to-speak....

So I built a L-OO to use as a mule for testing multiple tops over time. Every instrument that I built back then had a stated purpose of usually three variables that I wanted to play with. Specific goals for my own development as a builder if you will. The L-OO has a bolt-on neck, no glue for easy removal.

Then I spent three months building 10 different tops trying different ideas, etc. and attaching them to the mule guitar and playing the thing for a week or more to try to determine what I had. After the 10th top was evaluated I called it good and left it as-is, glued the fretboard extension of the neck in place, and that's how she sits today. It's my personal favorite guitar, not much to look at, super light weight... does not sound fantastic but it does sound like a good, honest, mahogany instrument and that workes for me.

So my long-winded suggestion for you is to perhaps use the top or tops that you are not thrilled with to explore top voicing. Some builders want super stiff tops with Somogyi known to go through 1,000 tops looking for one special, stiff top. Kent Everett likes to be able to wring out a top shaking it like a blanket looking for a sound not unlike a musical saw from the old days. Kent makes killer guitars that in his case do not depend on super stiff tops.

I'll introduce a notion as well which goes like this: Is it really the top that is the major contributor to the resulting guitar or is it the "top system" that includes how and where and how much or how little we brace? I tend to personally think so but who knows... Just wanted to let you know that one man's "dull" top may be part of another person's killer top system.

So there you go you can make multiple tops and try to expand your knowledge of what results in what or you can believe that your dull top may simply need some nice adi bracing in the right amounts and places. You can check out how Kent does things since his methods are not dependent on that one in a thousand top.

Hopefully there is something here that helps because that's the entire point!

PS: Before I hit "submit" I see that Greg posted and posted an excellent reply. We are not in complete agreement, never an issue for true professionals and very much illustrates how there are no stead fast answers for lots of these Lutherie questions. Greg could be far more correct than I was or am, who knows. But what I do know is that we are all the better and a better forum because folks with different views can express them and it does not get personal. Great post Greg!

There will be more points of view too including the sorts who will simply reply - send the top to me....

Honestly, until you get a few under your belt and have an objective as to what you're hoping to get out of any given guitar, I wouldn't get too obsessed with the 'tap tone' of your wood. Build, assess, gather data, take notes...and buy the Gore/Gilet books...

Thanks. Hesh, you echoed my thoughts almost exactly, but it means much more coming from your experience level than my naive 'hunch'! Greg, I think we agree, except your last sentence. In my day job, I am duty bound by scientific research, methods, and outcome-driven practices, so I definately see where your comment is coming from--however, there are so many variables (more than Hesh's three per build!) that applying true scientific method would be nearly impossible at best. I suppose you could rig testing jigs for the new plates, but what the *final* product (in someone's lap) sounds like may not correlate well with early stages of the build. (just my guess) I cannot argue however, with the folks who get consistent, excellent results----and I ask, do the most reputable builders use sophisticated testing equipment? I don't think so--they grab chunks of wood, hold them with the requisite body English, and tap away, then either smile or grimmace. For now, I'm taking the third post's advice and just building, and taking notes along the way. Since even if I live to 100, that won't be enough time to master this business, I'm gonna have fun along the way. I guess with all the above comments in mind, I would be interested to know how well people estimate their success in predicting final tone quality along the way. Anyone build with a dull plate that ended up sounding great? Does it happen enough that some just don't give a rat's patoot what wood taps like early on?

Well Trevor Gore has done a pretty good job at it. Once again, get the Gore/Gilet books.

Ed's right just start building and now that you mentioned your day job you may find that you can draw from the scientific method when you wish but also chalk up much of what results to the chance aspects of Lutherie. You also mentioned that you want to have fun and I see the right mindset in you for fun too.

Regarding the big names in the biz it's worth noting too that many of these folks, men and women, do not use the same methods as each other and may not agree with each other too as to how well some of these methods work. This goes for the authors as well and everyone else. There are no set ways to build that clearly shine above all others.

This madness started for me with a guy who was on the left coast most of the time but lived in middle America. I never had any time and started having some early onset hypertension and other health issues. My doc suggested a hobby, I loved guitars and decided to try a Stew-Mac kit.

What resulted and this was before I even knew about Internet forums was a not very pretty, not very well built, not easy to play GLO (guitar like object) that quite frankly sounded better than my HD-28... Not what I expected and even though in time even the garbage man did not want the thing... (true story...) the tone was enough for me to fool myself into believing that I had some talent with Lutherie. So I built another, and another and more and loved every minute of it. My company would send me to Europe and then I had to tell the TSA why my suitcase was filled with Euro spruce.... Go figure.

You are right a full lifetime even when starting early is not nearly enough time to start to fully grasp some of this stuff and believe it or not and even though many will disagree we simply may not know the true answers to some of the important Lutherie questions of the day.

It can be a bit like golf too and I am reminded of the late great Freddie Prince who used to say that it was no secret that he was a cocaine addict so he took up golf. If anyone thinks that golf is less expensive than drugs they have a few things to learn.... Lutherie will suck money like there is no tomorrow but Lutherie also has a very fond place in it's heart for those who innovate, do more with less, are good stewards of the scarcity and rarity entrusted to them, and can both apply science as well as intuition. It can be many things to each of us and often is.

It intrigued me to no end and as such I ended up changing my entire life so that I could play with Lutherie every single day. I'm happier than ever now and even happier to have lots of decent music and the very fine people who are creative enough to make this music in my life. In a single day the set-up and string selection that we do can be the difference that helps a little girl make that chord that she has been needing for her favorite song or get Mr. Greaseball who no one could satisfy raving about our work and asking for business cards.

I suspect that much of this is resonating with you and that you will know what to do and how to get there at your own pace. Let me know if we can ever help too and we would be very happy to do so.

As for building with dull plates, sure, it's likely that most of what has been built by most of us would qualify as a dull plate to start with. What can result and often does because we take the time to try to exceed what f*ctories do is likely a lot of instruments that may sound superior to a lot of f*ctory instruments. Or, in other words, we may have been being duped all along by the f*ctories in so much as do you think that f*ctory workers typically... will get promoted for stopping the line because a little bird told them that this plate was a dullard?

With this said my belief is that the bar is pretty low in comparison to the f*ctories.... and small builders can easily exceed the value offered as a result.

Most of all though it's fun, rewarding, new, lots to learn and do, great justifications for buying tools.... , and a rather romantic notion as well that in my view is a great balance for an otherwise scientific mindset.

Lutherie is also great compensation for being a frustrated, lousy player.... I know.....

I use a somewhat different 'tech' approach to top voicing than many other makers do. I'm not saying it's 'magic', but it does seem to work for me with a wide variety of top woods.

"Dull" Everybody has a different way of using tone descriptors, so what do YOU mean by dull? I'm assuming that by 'flimsy' you mean that it has low cross grain stiffness? That seems to often correlate to a short 'ring' in the tap tone, which may be what you mean by 'dull'. It might not mean that the wood itself has high damping; sometimes it's just a matter of the way the lengthwise and crosswise modes stack up.

Mark Blanchard gave an interesting talk at the Healdsburg festival a few years ago about his methods (which are similar to mine) of top voicing. We both use Chladni patterns in our work, and he had been looking at the patterns on unbraced tops. (Chladni patterns are visible manifestation of the 'tap tones' of the wood/top, and tell you something about the way the stiffness and mass are distributed) Normally I've worked with the patterns of braced tops; using them to indicate where the braces are too tall. Mark hoped that, by 'tuning' the patterns on the unbraced plates he could then just go ahead with the same sort of bracing on every top and have them work. As he said, he wished he could get back some of the time he spent on that one.

What he did find, though, was that he could see more or less the same sort of resonant mode shapes on all of the tops, with the patterns being 'better' or 'worse' depending on the wood and the shape it was cut to. He also found that the guitars he liked better had 'better' patterns for certain modes in the unbraced plates, and were easier to tune with the braces on. The key is the relationship between the stiffness ratio along and across the grain, and the shape of the top. To make a long story short, he found that using tops with high cross grain stiffness worked better on broad guitars, like Jumbos, and ones with lower cross grain stiffness came into their own on things like 0's and 1's, that are relatively narrow compared with their length. Now he just joins his tops, cuts them to the shape of his largest (and widest) pattern, and checks the modes. If they don't work the top gets cut down to the next smaller size, and so on. Usually there will be some shape that the top works on, and that's what it gets made into. The moral: don't try to fight Mother Nature; figure out some way to work with her.

I've been looking at the 'Blanchard modes' of unbraced tops ever since. He's right in saying that the 'tone is in the top': it's really hard to make one with 'poor' patterns in the unbraced top work well simply by what you do with the bracing. He's not the first to find that bracing, at best, 'fine tunes' a top. That said, if you have some way to know when the bracing is working with the top you can correct some problems, and at least get a nice guitar even when the top is less than promising.

Sometimes a top will sound 'dull' or 'dead' if it has run out. Since run out can change as the tree grows you might not see it as a change in reflection along the center joint: it could run out in the wings. In that case the line of reflected light, as you look at the joined top with the light behind you, will run more or less diagonally across the top, rather than straight across as it should. In a case like this the Chladni patterns will be distorted; twisted 'up' on one side and 'down' on the other. This can often be corrected by making the braces taller on one side than the other; using asymmetry in the braces to correct the asymmetry of the top. Tops like this can be confusing, but can make a nice instrument if you persist and get them to work right.

At this point I tend not to reject tops unless they're really 'dead' and/or dense. I had to send back some redwood recently that was like that. It's the first time I've ever returned wood. Usually I can find something that a top will work on. If nothing else you can use a 'cosmetically challenged' top on a 'test mule'.

Um, yeah... I don't think I would throw out the Intuitive approach nor call it inferior to a more "scientific" method per se. There are a LOT of great builders out there who use a purely intuitive approach, and it works extremely well for them. At first, it is simply training one's senses to the responses they are experiencing. After awhile, the information gets processed and what may seem like intuition is actually a pretty well educated and accurate approach. Either way, you are first learning to gather data, process it, and then apply the information in practice. And this does take time, and people with enough wisdom end up understanding that the learning process is always continuing, and that you never have all the answers...

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"I want to know what kind of pickups Vince Gill uses in his Tele, because if I had those, as good of a player as I am, I'm sure I could make it sound like that.
Only badly."

Thanks again, all. I will seek out the Gore books. Many comments rang so true....especially the one about being a lousy player!

Don:
I would NEVER put down the intuitive approach, or, indeed, any other approach that works for somebody: I was just talking about the way I do it. Each way of doing things has its advantages and disadvantages, and some approaches work better for some folks than others, for whatever reason. As you know, my hearing is such that I tend to not rely on it too heavily, and a 'tech' approach that can work around that issue is a help for me. On the down side the signal generator costs some money (I made mine, but it was still not 'free' by any means).

The big drawback of the intuitive approach in my mind is that it takes a fair number of guitars and a lot of time, to internalize the data. I can teach somebody about Chladni patterns over the 'net. If I send you the data on a guitar that worked you should be able to come pretty close to duplicating it if you can find the right pieces of wood for the top and back. As Mark Blanchard said to me once:"It's a package. You taught me how to do it, and my guitars sound a lot like yours. I taught a student, and his sound like mine". I'm not saying I make the best sounding guitars out there; that's a matter of opinion anyway. However, for better or worse, it seems to be a way to get pretty consistent results.

In the matter of 'science': when we made a video of plate tuning a few years ago I had to talk the guy out of saying it was 'scientific'. It would be very difficult to demonstrate that 'free' plate tuning (or any other method, for that matter) works to a degree that would pass muster in a juried journal. Like everybody else with their method of choice we're relying on anecdotal evidence and belief. It's entirely possible that all the glitter I've used up over the years has not done anything for me at all, and if I'm getting better (as some of my customers seem to think) it's because I've been at it long enough to internalize things. I do some 'science', but it's mostly concerned with simple stuff like figuring out how strings work, ports, and what changing the break angle really does or doesn't do. With the time those simple projects have taken, I'm pretty sure I wouldn't live long enough to prove' that plate tuning works, even if I make Strad's age.

As Hesh pointed out great question. But what about the great answers of Greg, Hesh, Don and Al, thanks gents.

Steve

Some interesting discussion here, but I think most of it misses the point.


Can we assume that before joining, the wood tapped OK? (If it had sounded that bad before you joined it, you wouldn't have bothered, right?). Anyway, I'll run with that assumption.

When you double the size of a panel by joining it, its tap frequencies drop significantly (there's a bunch of equations in the book that prove that, and a lot of people who just know it from having joined panels) and the damping increases massively because the larger panel has to move more air as it tries to vibrate. In the book, I advocate tapping half panels and working from there to determine a target thickness because measuring the vibrational frequency of joined panels is quite difficult (low and muddled mode frequencies and lots of damping). Some other well known authors advocate thinning joined panels until the tap tone is "quenched" (read "dull").

You're probably getting the picture. It is situation normal for joined panels to sound a lot "duller" than before and it is not necessarily a bad thing.

So just carry on. The wood hasn't changed, but it is in now in a structure that responds differently.

[Knowing exactly what thickness to leave it at is another question, but you have plenty of advice as to how to get an answer.]

Conundrum: The "quenched" philosophy is one place to start. But tops for classicals are nearly always thinner than tops for steel string guitars. "Quenched" only gives you one thickness.

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Trevor Gore, Luthier. Australian hand made acoustic guitars, classical guitars; custom guitar design and build; guitar design instruction.

http://www.goreguitars.com.au

Trevor--not really. The half plates were kind of dull too, before gluing. (by dull, I mean exactly what AlanC described. After the thump, there is no residual "ring")

Being at my early stage of the game, I went ahead and glued the plates, and constructed a top (which is being glued onto the sides as I type) having made notes along the way. I did note that the tone seemed to dull even more after joining, as you mention. After thicknessing and bracing, it improved to slightly better than the original half plates. This is all very subjective in my mind's eye, or ear, I should say. We'll see how it sounds in the finished product in a couple weeks.

FWIW, I did leave the bracing a little taller than I normally would like to. More to address the very flexible nature of this top, than any feeble attempt on my part to affect tone.

No matter how this one turns out, I really appreciate the excellent comments, and have learned much. Thanks all!

I am not sure what I would correct a tap tone -- from what to what? If I were an experimenter or wanted a "sales gimmick" I likely would use some of Roger Siminoff's tests and gadgets. But I am indeed just a "copycat" so when I want to replicate a certain guitar I make it as close to the original as possible. I have found that a sound board does change characteristics along the construction sequence, I suppose that is to be expected. Along those lines I would offer one suggestion regarding "are tap-tones correctable." I believe they are changeable so -- what I have found to be useful is to glue the sound-board to the rim first that way if the tone I get is tight (to my ear and tastes) I can still do some brace shaving. Testing as I go with a dulcimer hammer. BTW I don't think I have super powers -- I leave the back off a few days and bonk and trim once in a while to make sure I am hearing what I think I am hearing. I believe any body can hear a clear resonant tone and a long decay. Than again maybe if I did nothing that would be OK too?

If memory serves I believe Tom Rebekke holds a patent on the "tail block trap door" so a maker can remove it to reach in and shave braces if he so desires.

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Ken Cierp

http://www.kennethmichaelguitars.com/

IME, the answer is no. If the wood sounds dull, the guitar will sound dull. Although after thinning a plate, but before bracing it, it will likely be too floppy to give a clear tone. That's fine. It comes back after bracing. But if it was thunky before thinning, it will probably be thunky after bracing too.

That said, it's still very easy to screw up with good wood. Factory guitars always go for mediocre, so the difference between good and bad wood is comparatively small. But for high performance hand builts, if you want a guitar that feels alive, you need wood that rings, and skill to get the most out of it.

Spruce that thunks now may (or may not) ring nicely after 5-10 years of seasoning. Good spruce is a lot harder to find than good redwood and cedar.

And I agree with Ken that it's best to glue the soundboard to the rim before the back, especially if you like using thin plates and stiff bracing. With a thick plate and minimal bracing, you can tune the perimeter stiffness by sanding from the outside. But thin plate style, you need to be able to shave the ends of the braces and hear the effect with the perimeter constrained.