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I don't know how to pose this question, but I'm always surprised that people are looking for a lightweight guitar. Yes, a lightweight guitar does indicate a light and responsive construction, but that can be applied where necessary while weight in other places might be beneficial too. I am thinking about very solid neck with rosewood or something like double sides.

I intend to test this on my next build. I have some very beautiful pieces of Brazilian that ring like a metal tube. If I build a neck out of that it should be heavier, yet not absorb much of the energy of the strings, and instead transfer them to the top right?

So, my question is adding weight in the right places could be beneficial or am I missing something?

Hi Joost and welcome to the forum.

This notion of lighter or heavier being..... better much to the surprise of some is a notion that you can always find examples that skew things in the direction that we might not think that it would. More specifically I don't care who they are.... no one exists who can tell you with certainty that reducing weight here or there or adding weight here or there will "always......" result in something predictable or beneficial....

As someone myself who craved light weight instruments coming from the low mass audiophile tone arm whack-job world... depending on the application and variables I don't believe any more that there are any absolutes in our trade as to what the outcome of a gram here or there will always..... be with certainty.

No offense intended to those who did the research, math, spent the time in the trenches etc. IME no one has adequately gotten to the point where they can explain exactly what is happening with an acoustic guitar. We have read many, many doctoral thesis available in every college town USA (and your country too) and there is no agreement.

I often read these questions on this forum and others where some folks think that they can ask this kind of a question and that there will be an Einstein here who absolutely knows the answers. Instead what you will find are lots of kind hearted folks who make valid observations, may have lots of experience.... or not.... who are always willing to share their 2 cents and that's a good thing too or we would have nothing to talk about.... The answers received that should not have been offered are not what bothers me. What bothers me is the very idea and anyone at all knows the answers to many of these "tone" related questions.

But will you find your answer here - no. Will anyone here know with absolutely certainty what the answer to your specific questions are as applied to the instrument(s) that you have in your life and we have never seen - hell no.

Which brings me to my suggestion which is this is what's great about Lutherie there is so very much snake oil and unsupported notions in our field any of us could spend the rest of our lives debunking this stuff and still likely not be very far along the way to being capable of explaining with absolutely certainty just exactly how acoustic guitar works.

Back to your question: "Adding weight in the right places could be beneficial?"

answer: sure, now you have to find where the right places are for YOUR instrument and how much weight will help for YOUR instrument. It's also going to he a factor of who's playing the thing, how hard they hit, what they play, strings, room, weather......... age..... and much more.

A related question might be the same question but removing weight and how that will impact things.

Do I know the answer? Heck no and it's about time that someone was honest about it too.....

Welcome to the forum

PS: I read your other post referencing Rick Turner and thought that I would do one of the things that he taught me to do, be a curmudgeon.......

Hello and welcome to the party.

I think you're right, sort of. I think that as long as the right things are left light, the supporting structure can have an influence on the timbre, without necessarily being worse or better, just different.

For instance, if a top was way overbuilt/heavy, perhaps most people would agree that it sounded worse than one built in a better fashion that was more responsive.

Whereas adding weight to the neck by using heavier wood might influence the timbre but not nearly as much as the top.

Some people do complain about neck heavy guitars though, just in the sense of playability.

Thanks for the answer so far. My only experimentation a different neck woods has been with electric guitar and there the differences quite obvious, so I'm in thinking that that should translate to acoustics as well.

A stiff 5 piece neck generally means more sustain, compared to a one piece neck and if you have something like really ringing Brazilian Rosewood for the neck, that seems to translate to more bass and treble, a wider frequency range if you will, for electrics at least.

I am thinking of using, double sides, solid rosewood linings and heel block to create an instrument that is balanced in terms of playability.

Also, these things will add to stiffness where I want it to make sure no energy from the top is wasted

Well, on an electric guitar, the most flexible appendage, asides from the strings, will be the neck, so I would expect changes in the neck to make a big difference, as the solid top is a very fixed anchor point for the strings.

Not quite so for an acoustic. The bridge of an acoustic is (hopefully) moving around all over the place in comparison with the neck, so I would expect changes to the neck to be less obvious.

If you're interested in the more technical aspects of how acoustic guitars work, and how to manipulate certain parameters to achieve tonal objectives, I recommend the Gore/Gilet books 'Contemporary Acoustic Guitar Design and Build Vol 1&2'.

Are you seriously planning to use Brazilian rosewood for an entire neck? What would that represent? $1000 of wood?

The flip of that is you would have a guitar with a heavy neck. Most players dislike a neck heavy instrument.

So you would be building a tonal experiment using unbelievably expensive woods that would likely suffer from playability issues regardless of the possible improvement in tone.

I would certainly suggest there are better ways to experiment with neck weight and density. How about building a bolt on with one light Spanish Cedar neck and one EIR neck? You can swap them out and see what you think the difference in tone might be. Save the precious woods for when you are not experimenting.


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No, not entirely, I will build a five piece neck, with two Maple wedges between, it's just that the Brazilian I have is too narrow for Fretboards, and I have plenty of bridge stock, so it would be the only purpose. Thought it could be fun for our 40th guitar.

I would of course make sure that the guitar remains well-balanced for the player. It will not be neck heavy.

A 12 fret would be less neck heavy. Built a 0 sized guitar with wood denser than rosewood, sitting not too bad but standing with a strap makes life interesting. Does have decent sustain.

"I intend to test this on my next build. I have some very beautiful pieces of Brazilian that ring like a metal tube. If I build a neck out of that it should be heavier, yet not absorb much of the energy of the strings, and instead transfer them to the top right?"

If the Brazilian Rosewood doesn't absorb any energy why would it affect the overall sound of the guitar any more than a cheaper/ denser wood like purpleheart or bubinga would? You might be better off saving the Brazilian for bridges or show wood where it's qualities do make a difference. If you have plenty of bridge stock you might trade it to someone who doesn't, for wood more suitable for your purpose.

BRW neck? Interesting proposition. I have always stuck with Hondo Mahog for the neck (usually 5 piece), so the weight variation of my guitars comes mostly from B&S wood choice and bridge wood (important in my opinion). If i use light B&S wood and light bridge they tend to sound to brash. Is that a word? I brace all guitars the same way depending on model.

No science in what I do, just observation. Lighter, non-oily woods like mahogony, sapele, & koa tend to make brighter and usually louder guitars when compared to rosewood builds. I like both sounds. My current playing guitar is a cobobolo. Mellow and earthy sounding.

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Joe Beaver
Maker of Sawdust

One other point, if this is going to be the flying buttress build you have spoke of then that changes everything. I would tend to go for construction techniques and material choices that have been shown to produce the sound in a flying buttress that I was after.

If you put another variable into the mix it will be hard to discern what went wrong and what went right. Just my 2 cents.

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Joe Beaver
Maker of Sawdust

This is an important point. Mass, Young's modulus, "Q"... these are all as irrelevant to guitar building as punctuation, grammar, and syntax are to writing. The "notion of lighter or heavier being" is the fundamental philosophical concept that transcends these distractions.

As long as top and bracing are "light", the weight of the rest of the guitar really depends on the type of design.
Weight in the sides is widely advocated, and with a reflective back, that could be quite heavy as well.
I don't think the rosewood neck will affect the tone significantly, it will be similar to all maple.
It's usually when necks are light and flexible that the neck resonance becomes significant.

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A man hears what he wants to hear, and disreguards the rest. Paul Simon

Yes, you can make great sounding guitars of just about any weight. The soundboard (including bridge) is the only thing that necessarily needs to be light. Theoretically speaking, the ideal is probably a massive neck and side structure with light soundboard, and medium weight, low damping back. But light neck/sides seem to sound good too, so I'm not sure how much it really matters. I build lightweight for the feel, not because I think it sounds any better.

I agree with Fred, 12 frets are good when using dense neck woods. If you use a cutaway and low-profile heel, it gives about as much high fret access as a typical 14 fret cutaway with chunky heel.

That said, changing from a mahogany neck to Brazilian rosewood isn't going to make as much difference to balance as changing from full size Grover Rotomatics with metal buttons to Gotoh 510 minis with wood buttons... Tuners have a lot of leverage, being out at the end of the neck.

Well, it will affect the sound in two ways, firstly because it doesn't absorb as many frequencies, those frequencies will be freely moved to the top, and secondly it will improve sustain, which is what I've noticed on electric guitars as well. It was always an improvement over maple or mahogany

Since I used to be a buyer an seller of Brazilian Rosewood, I have more bridge stock than I could ever use up. It would be harder for me to obtain some good Purple Heart or bubinga then real nice quartered Brazilian for this purpose. I've had this lying around for years, and I always intended to try something like this because I don't need the bridge stock and it is too narrow for anything else.

The first few guitars I built with square steel solid non adjustable truss rods. Since then I have adopted the light is better philosophy and have been building better guitars however there is something missing that those heavy neck guitars have. It might be sustain, attack, or something I can't quite put my finger on. I think the neck has more to do with the tone of an instrument then most people think. Of course the downside is balance. If the guitar is neck heavy then it's virtually worthless and unplayable. So there is a happy trade off point some where in the middle.

Amen to that - I believe most famously Michael Kashsa indicated that he had it figured out, the folks at Ovation too. I'll stop there. The point is, there is no consensus.

I personally like to keep the sound board structure lightly built -- but there are those that will tell me I have to take care or I will over drive -- seems to me the player touch and the string set tension are adjustable variables dictating that end result. So I believe there usually is a ying and a yang for most of our build choices.

To my ear one of the best sounding Martin OM's I played was on a rack in a store in State College PA right along side other Martins of the same style. This one noticeably weighed far more than the others. I made that comment to my brother he agreed, but in the end the only difference was the totality in weight of the materials used for that particular guitar. I did not go back to our shop and try and build a heavy guitar.

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Ken Cierp

http://www.kennethmichaelguitars.com/

This is also where my focus is placed. I've built both heavy and light guitars that were equally acceptable tone wise but different. Building light or heavy for me is not something I work at but is dictated generally by the wood choices. One concern I try to address is balance,so in a light body I tend to use open backed tuners and a lighter neck wood. Keeps me happy.
Tom

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A person who has never made a mistake has never made anything!!!

You hear lots of opinions on what variable leads to what tonal difference. Most of it seems to come from lone data points made with a priori assumptions. We humans tend to observe what we expect/hope to observe. There have been many who have taken a more systematic approach to describing how these machines we like to build work. When they talk. Even then I temper my expectations that their work will translate to mine in a predictable way. We need to be careful about mixing terms too. When someone says heavy others might hear mass while another will think density and a third will be talking about stiffness.

I have a hopelessly low number of data points to make any claims. What’s more, they are all uncontrolled; it is difficult to make truly controlled observations in this game even if we pretend it is not. As such, I take my educated guesses and try to make the best guitars I can.

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

As has been said, acoustic guitars and solid body electrics are much different systems, and you can't expect much carry over from one to the other.

I have not done much work with solid bodies, but did observe some interesting things when I did a long time back. You can think of a solid body guitar as a bar, like a xylophone bar, but with a weird shape. It vibrates with the same sorts of resonant modes that a xylophone bar does, but they're not tuned to harmonic pitches the way they would be on a xylophone. It's easy to find these resonant modes: try holding the guitar up by pinching the neck at or near the nut and tapping on the back of the head, or somewhere near the top of the body. It's often easy to find the lowest three or so modes, which will often be down in the range of the fundamentals of played notes.

One interesting thing I've noticed on 'good' solid bodies is that one of the inactive 'node' points for those lower modes will be very close to the bridge: if you tap there you don't hear them. This means that the bridge is not moving at those pitches, and that they can't be easily driven by the strings pushing on the bridge. It's possible for those modes to have active areas (called 'antinodes') at the fret that is producing that pitch for one of the strings, and that will be a 'dead note' for that guitar. Basses suffer especially from this. To keep the length down they put the bridge out at the lower edge, and this is the most active place for all the vibration modes of the body. The strings can drive those modes easily, and the energy gets sucked right out of them at those pitches.

Acoustics generally have a somewhat shorter neck, that is often both thicker and a bit wider than the neck on a solid body. Acoustics are enough lighter in weight that the resonant 'bar' modes are generally higher in pitch than they are on solid bodies, and they're much less active. The only one I've found that had any effect on the tone at all was the lowest pitched one, and then only in very specific circumstances. More to the point, the top on an acoustic is much more flexible, as has already been pointed out, so it's resonances are the ones that color the sound, not those of the neck for the most part.

Hesh is right in saying that it's unlikely that we'll ever understand these things perfectly. It's not that the physics is weird; this isn't quantum mechanics, but just that they're far too complicated. One of my customers designs satellites, and uses software that can evaluate the resonances of them so that they can see if they're likely to shake themselves apart on launch. He tried inputting the data on a guitar, and it was too complicated for the program. This is not rocket science; it's harder.

In a case like that, the best way to proceed is often to follow some standard design. Lots of smart people have been building guitars for a long time, and every one of them has tried to make a better one than anybody else. Almost everything you could think of that uses a 'traditional' material has been tried, usually any number of times. Things that didn't work are simply forgotten, although they do sometimes turn up in some dusty cupboard someplace. If the result was notably better than average all the other makers copied it as fast as they could, so they would not be left behind. Pretty much anything that works that doesn't rely on some new material is thus already a part of the standard design.

This has two outcomes:
1) it's awfully hard to make a big improvement in the standard designs, and,
2) small differences, which are usually on the order of build 'tweaks', become very important.

It's awfully tempting to try to re-invent the wheel, and come up with some radical design that's going to set the word on it's ear. The vast majority of the radical designs I've seen have been, at best, a little better. Most were terrible.

Finally, (I know, it's about time!) I'll point out that it's possible to make specific changes in some cases by controlling the weight in certain ways. Trevor Gore bolts large weights to the sides of his guitars in the 'flat' area below the waist. This, in some sense, 'keeps the sound in the top'. Since the top is the part of an acoustic that is most effective in turning string energy into sound this helps to make his guitars louder than most. I've heard varying opinions about the tone, but there's no denying that he accomplishes what he's out to do, which is to make it louder. There's an experiment that has worked, at least insofar as the experimenter is concerned. Whether that, or any of the other 'new' features like sound ports or cooked wood or whatever will become parts of the new standard time will tell.

I just changed my signature quote to honor Al C. He gets it! Lots of others do too but the point remains that tone is always going to be subjective as all hell and regardless of who thinks that they understand why a Stradivarius sounds like it does..... the safe bet is that they are full of crap....

I'm not saying that we will never progress or these mysteries of the acoustic guitar will not be incrementally revealed to us with perhaps even a pretty good overall understanding of the instrument some day. I am saying though that the computer that's likely to be capable of this has not even been envisioned yet.

Tone may be like fine scotch too where subtile differences, individual tastes, etc. come into play. I've yet to know a computer who is a scotch fan but if you guys know of one let me know, I want it....

I'm a Lutherie business co-owner and out in the field dealing with real musician's issues on a near daily basis. Here's an interaction that happens in our shop every day that illustrates my point regarding how subjective tone is.

Client: You guys have a great reputation would you recommend a pup system for me?

Me: In what sense, quality, ease of installation, quality of the company behind it?

Client: No I want one that sounds killer....

Me: Well you won't find either Dave or I commenting very often on tone, it's simply too subjective and what we perceive may be different from what you perceive....

Client: I'm disappointed, you guys have a such a great reputation...

Me: How do you think that we got that reputation AND how do you think that we maintain it - not commenting on subjective matters....

Client: OK, sorry, I get it now....

Now they don't always get-it but tone is and will remain subjective as all get out.

More specifically and no offense to the OP for some years now in private I've been commenting on these threads where someone comes in and asked if they do this or that with this or that what will the result tonally be.....

I'm always amazed that people actually believe that someone here or anywhere would actually know for sure. That's my point.

OTOH there are never any shortage of answers offered either......

Lastly for now when ever I think that I understand something something else comes along that turns my belief on it's ear.... Welcome to Lutherie!

I wanted to think of torification/torifaction as snake oil and then I heard one of the best sounding to my ear instruments ever with you guessed it, a torrified top.

I wanted to think that light weight instruments were the cat's meow and then I heard a Smallman... that projected like nobodies business.... And so it goes......

Hesh, you just beat me too it.

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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.

The good news is when they are set up properly we sometimes can end up with a great sounding musical tool seemingly by accident.

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Ken Cierp

http://www.kennethmichaelguitars.com/

Wow. And just when I thought I was beginning to get a handle on this craft and move a little closer to a build that sounds consistently great. Then I went and read this thread. But seriously. The one thing that struck me is that we're always trying to put our fingers on the factors that consistently move the quality of tone one direction or another. But the materials we are using are not measurably consistent. Wood just in one specie alone varies greatly in its sound giving qualities I've built my necks always of mahogany. And noted great differences between each one. Possibly density? Amount of resins?
Age? And as Hesh noted what is the "killer" sound? Different to everyone. We all expect a different great sound from a stringed instrument.
I'm not saying that it's not possible to analyze. But yes, it is beyond rocket science. This is just one reason which makes this craft so enjoyable. Not to mention the great talent this forum taps into.


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"It is easier to fool a man, than it is to convince him that he has been fooled"
Mark Twain

I agree to some extent, but you have to keep in mind that the standard designs are also optimized for production efficiency and warranty minimization. We hand builders can afford a lot more man hours per guitar, and can expect our customers to be more careful with them, so our fully optimized designs will tend to be a bit different.


I need to try one sometime. From all the descriptions, it just sounds like a process to turn spruce into redwood But to my ears, that would indeed be an improvement. Most of the time, anyway. Last year I built a steel string harp ukulele with a thunky sounding riftsawn bearclaw sitka top, and it turned out to have the magic. So that's one more data point in the category of "you can't explain that"