Gibson quality....

[Spence]

Look up young's modulous and the speed of sound through different types of wood. Fascinating stuff and the basis for a true custom pickup maker's craft.



Along Fibre: Across Rings: Along Rings:
Acacia 15,467 4,840 4,436
Fir 15,218 4,382 2,572
Beech 10,965 6,028 4,643
Oak 12,662 5,036 4,229
Pine 10,900 4,611 2,605
Elm 14,639 4,916 3,728
Sycamore 15,314 4,567 4,142
Ash 16,677 5,297 2,987
Elder 15,306 4,491 3,423
Aspen 16,677 5,297 2,987
Maple 14,472 5,047 3,401
Poplar 14,052 4,600 3,444

These are examples of the considerations a knowledgable luthier will build into his design. Afterall, strength is a secondary consideration to tonal qualities.
Understanding this subject gives a whole new meaning to waking up with wood.

[David Schwab]

That's interesting.

Which way do the numbers go?

[corduroyew]

Look up young's modulous and the speed of sound through different types of wood. Fascinating stuff and the basis for a true custom pickup maker's craft.



Along Fibre: Across Rings: Along Rings:
Acacia 15,467 4,840 4,436
Fir 15,218 4,382 2,572
Beech 10,965 6,028 4,643
Oak 12,662 5,036 4,229
Pine 10,900 4,611 2,605
Elm 14,639 4,916 3,728
Sycamore 15,314 4,567 4,142
Ash 16,677 5,297 2,987
Elder 15,306 4,491 3,423
Aspen 16,677 5,297 2,987
Maple 14,472 5,047 3,401
Poplar 14,052 4,600 3,444

These are examples of the considerations a knowledgable luthier will build into his design. Afterall, strength is a secondary consideration to tonal qualities.
Understanding this subject gives a whole new meaning to waking up with wood.

Now thats what I'm talking about. What really gets things complicated is when you start to factor in runnout and figure. When the grain is only 1/8" long before it gets cut (like in a flame maple top) then how does the sound transfer from end grain to end grain? How much energy is lost? I'd like to see math for that.

[David Schwab]

Now thats what I'm talking about. What really gets things complicated is when you start to factor in runnout and figure. When the grain is only 1/8" long before it gets cut (like in a flame maple top) then how does the sound transfer from end grain to end grain? How much energy is lost? I'd like to see math for that.

I don't think any energy is lost, because sound doesn't travel only in the direction of the grain.

Wood on a whole is a bit more homogenous than that.

Some examples to consider; many extremely high quality arch top guitars and members of the violin family are made with curly maple. This includes the necks, backs and sides.

Is the wood flat, rift, or quarter sawn?

What happens at boundaries, such as neck and body laminations?

Woods such as mahogany don't have regular grain lines, and instead have interlocking grain.

Some figured wood, such as birdseye maple, is considered to be denser than the non figured variety. This can be true of curly maple as well, as the wood was under compression to create the figure.

My experience is that figured maple sounds exactly like the non figured piece, as long as it's from the same spices.

Quilted maple is usually big-leaf maple, which is softer and redder, and isn't as bright as hard maple. But even a quilt top will be brighter than a body without a maple top (assuming the body is mahogany or some other softer/lighter wood).

Energy is lost to flexible parts. A flexible neck will kill sustain more than anything. The stiffer the string supporting system is, the more sustain you will get. This is why laminated necks and carbon graphite reinforcement work so well.

The only thing you have to look out for with figured wood is its stability. It can tend to warp and twist after you cut it, because the tension was released.

I've got a really snappy and bright Tele style guitar I made with a 1 3/4" swamp ash body with curly soft maple top and a curly hard maple neck.

It sustains like a Les Paul, and sounds like a Tele.

[Spence]

The point I'm making is that regardless of the wood species and grain direction in a guitar, you can measure the speed of sound through it. That way you can determine exactly how to make the right pickup for the guitar.

[DrStrangelove]

The point I'm making is that regardless of the wood species and grain direction in a guitar, you can measure the speed of sound through it. That way you can determine exactly how to make the right pickup for the guitar.

It's important, alrighty.

Another aspect is damping -- how much vibration is lost in transit?
The damping changes with frequency, too, but the one sure thing
is that denser woods (like ebony) emphasize bass more.

This general property of frequency-dependent damping is called viscoelasticity.
It's hard to predict so luthiers educate their ears by rapping on wood billets and
paying attention to the sound.

As an aside, Corian is about twice as dense as ebony and, used in a fretboard,
emphasizes bass as you'd expect. The surprise is that it is less damped than
ebony, and gives a snappy percussive sound as well.

-drh

[SteikBacon]

Hey Spence, can I ask where you got that speed-of-sound info from. This is something I have tried to find for a little time now. I´m looking for some more numbers about stiffnes (these are related to speed-of-sound, I know, but can be helpful trying to communicate to other), density and what Strangelove called viscoelasticity.

My understanding is: the goal for max sustain is to send the soundwaves out to as much material as possible at no time at all. (Given that the material don´t absorb but send the wave further on to more material). Then to shape sound goes from there to choosing less stiff wood, lighter/softer, blahblah, down to laquer.....

BTW, my english isn´t the best , what do you mean by "dense"? Is it something like "tight" wood....

Never mind, found out. Didn´t know it was called Young´s Modulus..

[Spence]

Young's modulus can also be used to determin a wood's elasticity. So as you've asked about density too I thought I would point you in the direction of the Left Brain Luthiers:


http://www.ukuleles.com/Technology/woodprop.html


Enjoy.

[David Schwab]

I´m looking for some more numbers about stiffnes

For stiffness you want to look up "modulus of elasticity."

My understanding is: the goal for max sustain is to send the soundwaves out to as much material as possible at no time at all. (Given that the material don´t absorb but send the wave further on to more material). Then to shape sound goes from there to choosing less stiff wood, lighter/softer, blahblah, down to laquer.....

No, quite the opposite. The less of the string's energy absorbed by the support structure, the more the sustain. If the vibrations (and they aren't sound waves until they are in the air and strike our ear drums) are too easily absorbed, that uses up all the available energy from the strings.

I like to use the analogy of a banjo. As I'm sure you know, a banjo is basically a tambourine with a neck and strings. To produce sound, the bridge vibrates the drum head. Because the drum head has so little mass, it uses all the energy of the strings, so you get a fairly loud tone, and very little sustain.

The exact opposite would be some sort of composite instrument, like a bass with a graphite through neck.

Less of the energy is converted to "sound" and more is reflected back to the strings.

The reason why certain materials sound certain ways is because of the amount and frequency of vibrations absorbed. Softer woods sound warmer because they cancel out more top end, and reinforce the low end.

So you are on the right track. Stiffness makes a huge different in my opinion, and even more so than mass.

You can make a nice sounding bass neck from soft woods and plenty of reinforcement such as carbon/graphite bars, since they have a high stiffness to weight ratio

[corduroyew]

I don't think any energy is lost, because sound doesn't travel only in the direction of the grain.

Wood on a whole is a bit more homogenous than that.

True, it doesn't *Just* travel along the grain but the sound travels faster along the grain. Wood is also much stronger along the grain. When you start chopping the grain short it makes it significantly more flexible. That’s why we acoustic guys pay so much more for hand split billets. It’s not as big of an issue on electric guitars but it is still an issue and energy is still lost.

Some examples to consider; many extremely high quality arch top guitars and members of the violin family are made with curly maple. This includes the necks, backs and sides.

I'd like to point out that violins are not known for sustain. They were specifically designed to not sustain. If you pick one up and pluck it, you will see what I mean. Arch top guitars are not known for volume or sustain either and early archtop designs were based on violins anyway. Another thing to think about is that when you carve the top and back of the violins and archtop guitars, you are cutting all the grain so it's only an inch or two long anyway so the flame or quilt isn't changing the length of the grain nearly as much as it would be on a flat board. Plus people are willing to sacrifice tone for looks. I just built a Tasmanian blackwood flat top guitar for somebody with super tight flame on the back and sides. The guy told me he wanted the best tone possible. I had some with a little curl and I had some with a 5A flame pattern. I explained to him that the one with tight flame would not sound as good and cost 500 quid more and he still took the flame because the real bottom line wasn’t tone.

What happens at boundaries, such as neck and body laminations?

I’ve written quite a bit about the effects of laminating in other forums. It’s a very big subject that I just don’t have time to get into right now. Remember the old school fender necks that had a skunk strip because they actually needed them? Those necks have more punch than necks with glued on fretboards.

Woods such as mahogany don't have regular grain lines, and instead have interlocking grain.

True, and that is part of the reason it sounds so dark even though it's pretty heavy.

Some figured wood, such as birdseye maple, is considered to be denser than the non figured variety. This can be true of curly maple as well, as the wood was under compression to create the figure.

Kind of... Birds eye is denser because of the species. If you quarter cut birds eye then it’s not birds eye anymore, it’s just rock maple. Curly maple might be denser than plane maple (I don’t know) but it’s also weaker, softer, and more flimsy which means more energy loss. There are a lot of factors that determine overall tone. Grain pattern and density are just a couple of them.

My experience is that figured maple sounds exactly like the non figured piece, as long as it's from the same spices.

My experience says otherwise. When building flat top acoustic guitars there is a huge difference. Even if the figured boards and the boards come from the same tree you can still hear a huge difference. The difference in electric guitars is much less noticeable but I believe I can hear it.

Energy is lost to flexible parts. A flexible neck will kill sustain more than anything. The stiffer the string supporting system is, the more sustain you will get. This is why laminated necks and carbon graphite reinforcement work so well.

I agree, and that argument is part of the reason I don't like figured wood. Figured wood is more flexible.

[Ruel]

Glue

How does glue in a two or three piece mahogany body capped with a maple top affect the sound of the guitar? Anybody know?

[David Schwab]

How does glue in a two or three piece mahogany body capped with a maple top affect the sound of the guitar? Anybody know?

It doesn't.

[David Schwab]

True, it doesn't *Just* travel along the grain but the sound travels faster along the grain. Wood is also much stronger along the grain. When you start chopping the grain short it makes it significantly more flexible. That’s why we acoustic guys pay so much more for hand split billets. It’s not as big of an issue on electric guitars but it is still an issue and energy is still lost.

It's not an issue at all on a solid body. Any damn Les Paul with the most extreme top will sustain more than a Strat with a plain alder or ash body. There you go. Case closed. Build two Les Pauls and make one with a maple top, and one with a mahogany top. You know what you will hear? The maple top has a bit more bite. That's it. try it, then get back to us.

Energy is not lost because of the speed of transmission. Why do you think it is? The mass of the solid body overwhelms the mass of the strings, unlike on a banjo. You can't hear wood figure, as long as the wood is equal hardness.

The other thing is with a flat sawn top, which way does the sound travel? To the edges. Now how about with a quarter sawn top? See how it makes no difference at all?

I have a guitar with an acrylic plastic body. How would that factor into the equation? No grain!

I have a bass with a flat sawn figured hard maple top. I know it's hard maple because I resawed and bookmatched it my self. I have an identical bass with a quarter sawn zebrawood top. Zebrawood is pretty dense, as is maple.

Now from your theory the quartersawn top should be brighter. But no, the maple top bass is much brighter and has more presence. The maple top bass also has curly maple laminates in the neck.

Using your theory, the quartersawn wood will direct vibrations (they aren't sound waves yet) away from the strings, which would cause a loss of energy. But that really doesn't happen.

You are also forgetting about standing waves. The vibrations reflect off the sides and back surface of a solid body, and reflect back to the top. This causes cancelations. Non parallel surfaces, like with a carved top, or asymmetrical body contour, will prevent as many cancelations. And of course the standing waves on the vibrating string are seen as harmonic nodes.

An acoustic top is not hardwood. Conifers are very different. The growth rings are much harder than the rest of the wood. This is not the case with hardwoods like maple. You want a hand split billet because you want that wood to flex in a certain way and not crack. This also affects the strength of the top. This has nothing at all to do with a flamed maple top on a thick Les Paul body.

Acoustic guys also spend a lot of money on AAAAA curly maple for expensive violins and arch tops. Why doesn't the maple ruin the sound?

I built acoustics as well.

The bottom line is a harder top material will sound brighter. A curly oak top will have more sustain than a plain figure big leaf maple top because it's harder wood.

I'd like to point out that violins are not known for sustain. They were specifically designed to not sustain. If you pick one up and pluck it, you will see what I mean.

No, there were not "specifically designed to not sustain." That's a ludicrous statement. They were designed to vibrate. I used to play in a symphony back in my teens. Violins are loud.

They happen to be very light, and lack any mass, and have thin plates. Upright basses, which are designed exactly the same, sustain just fine. Why is that? Mass and string length. Build a solid body violin and listen to the difference.

The only stringed instrument that was ever designed with sustain in mind is the solid body guitar.

Arch top guitars are not known for volume or sustain either and early archtop designs were based on violins anyway.

Archtop guitars whole purpose in life is to be loud. Not known for volume? They were made to cut over a loud big band. They were called "orchestra" guitars. They were made like violins (they were called 'cello guitars) precisely because violins are loud.

I just built a Tasmanian blackwood flat top guitar for somebody with super tight flame on the back and sides. The guy told me he wanted the best tone possible. I had some with a little curl and I had some with a 5A flame pattern. I explained to him that the one with tight flame would not sound as good and cost 500 quid more and he still took the flame because the real bottom line wasn’t tone.

What is the definition of "would not sound as good". Brighter, darker, quieter? harsher? It's all subjective and it's all anecdotal. First off there's plenty of acoustic guitars with flamed backs and sides that sound great. Make two identicle guitars with the same wood, even from the same board, and they will sound different.

Just the fact that you think the guitar wont sound as good will make it come out that way. Look at other builders guitars. They aren't saying the same thing.

We know that harder woods, like maple, when used for backs and sides, sound brighter. Design a guitar around that wood and you are fine. But don't make a bright top with hard backs and sides.

That's why many builders put an access door on the guitars. You can fine tune those braces.

I’ve written quite a bit about the effects of laminating in other forums. It’s a very big subject that I just don’t have time to get into right now. Remember the old school fender necks that had a skunk strip because they actually needed them? Those necks have more punch than necks with glued on fretboards.

I've laminated quite a lot of wood. I really don't care what forums you posted in. Anyone can be an expert on the internet. That skunk stripe doesn't do anything to the tone. It's just a piece of walnut. The two necks are constructed differently. You really need to look at the truss rod and fillet, and where the fillet is located. It's a compression rod. Plus I'm not convinced they sound different at all.

Some 70's Ric basses had a walnut lam up the middle of the neck. Then they stopped putting it in. They don't sound all that different. It looks nice though. Walnut makes a nice bass neck, but a thin little piece in the back of a Tele neck wont do squat.

I have a fretless bass that for various reasons got two skunk stripe inlays on the back of the neck. It didn't change the tone at all.

My laminated curly maple/purpleheart Tele neck has a lot of punch. The purpleheart is the reason.

Laminated necks are stiffer, if done correctly. That will give you more sustain. It also eliminates dead spots. That and some graphite. It retunes the resonance of the neck up and out of the guitar's fundamental range.

True, and that is part of the reason it sounds so dark even though it's pretty heavy.

It's not dark sounding at all. It can be warmer than maple, but it's a bright enough wood. It's heavy, but so is maple. maple is heavier. It's heavy on a Paul because it's so thick! It's warm sounding because it's not a hard wood. It's pretty soft. Easy to carve, which is why it was so popular for necks.

Poplar, which is not as hard as either wood has a lot more punch.

Kind of... Birds eye is denser because of the species. If you quarter cut birds eye then it’s not birds eye anymore, it’s just rock maple.

OK.. see what you just said.. it's the species. I guarantee if you take a figured rock maple top, and a plain one, they will sound EXACTLY the same. Same wood. Same sound. Try it.

Curly maple might be denser than plane maple (I don’t know) but it’s also weaker, softer, and more flimsy which means more energy loss.

I can tell you have never carved a flamed hard rock maple top, have you? You are talking about soft maple. And even some of that stuff is hard. It's not soft and flimsy ay all. It's hard stuff. The figure makes it harder to carve, but it's very hard wood. Just as hard as plain maple. I've made necks with laminates of both. If the figured woos was softer, then it would have sanded away more, but it's not softer unless you pick a soft species of maple.

And that, is the real reason behind the difference in tone.

My experience says otherwise. When building flat top acoustic guitars there is a huge difference. Even if the figured boards and the boards come from the same tree you can still hear a huge difference. The difference in electric guitars is much less noticeable but I believe I can hear it.

We were talking about solid body Les Pauls with figured maple tops. That's not your experience. Any two guitars made from the same tree will sound different. Figure or not.

On my two cherry basses, one has a very plain back, and the other has a very figured back. These came from the same board. Guess which bass sounds better and has more sustain? The figured bass.

I agree, and that argument is part of the reason I don't like figured wood. Figured wood is more flexible.

It's not more flexible at all. It might be less stable though. Make your neck stiff and the tribulations with the body wood will fade away.

Neck design is everything in the tone of a guitar or bass. Almost any poor sounding instrument will benefit from a new better constructed neck.

I can't stress enough about the use of carbon/graphite in necks. If you aren't using the stuff in your acoustic guitars, you are missing something.

Sorry, but I disagree with most of what you are saying. Hasn't been my experience in the past 33 years of building solid body instruments. Ir applies more to acoustics, but even then I haven't heard anyone complain about figured woods.

Multi-lam necks, and two very different figures of cherry from the same board. The figured bass is a killer. The plain bass is mellower sounding with a bit less articulation.

[David Schwab]

As an aside, Corian is about twice as dense as ebony and, used in a fretboard, emphasizes bass as you'd expect. The surprise is that it is less damped than ebony, and gives a snappy percussive sound as well.

I make most of my nuts from corian. It's a lot more brittle than ebony too.

I haven't made any fingerboards from it, but I have used black paper phenolic with wood veneer laminations. The wood veneers on the bottom make it stiffer. It's hard stuff, but not very stiff. Phenolic has a nice lively tone.

I got the idea when my partner worked with Ned Steinberger building the fist two or three NS Double basses. They were made from laminations of maple veneer and thin graphic sheets in alternating layers. John made the forms for the laminations.

I've been wanting to make some fingerboards that way.

[kevinT]

whew....david, i can see you had a power breakfast this morning


Maybe i missed it in one of the posts, but i'll ask it anyway....is wood in the figured areas (the darker areas of wood) denser than the plain wood around it?

I'm thinking of knots in wood and how tough they can be to saw.