Question regarding construction

[griff599]

So, been pondering a little and thought the expertise here might have good thoughts. So we hear about solid backs over laminate, tonewood differences, and quality of laminate. What about solid backs that are more than two piece. Of course the D-35 comes to mind but really any guitar with a 3 piece back.

What effect would that have on tone as opposed to a solid 2 piece back. And while were at it, if stiffness is a quality that is wanted, couldn't some laminate be more stiff than solid.

thnx.

Originally Posted by griff599

...What effect would that have on tone as opposed to a solid 2 piece back. And while were at it, if stiffness is a quality that is wanted, couldn't some laminate be more stiff than solid...

A few things....

The "D-35 tone" has virtually nothing to do with the 3-piece back. Martin used lighter bracing top and back - 00 sized bracing on the top and 000 bracing on the back.

Assuming a guitar built in the traditional style, a stiffer back will result in a brighter tone. This can be tested because Martin went to tall/stiff #3 and #4 back braces in the late 80's. Some repairmen reduce the height of those braces to deepen/loosen the tone.

Laminate, assumed to mean multi-layered wood in this case, guitar backs and tops are certainly tougher than solid wood, but not necessarily stiffer. In general plywood is not as stiff as solid wood of the same dimensions, but it is less likely to break under identical loads. It is also heavier. None of that is particularly helpful in building great guitars.

[Mr Fingers]

Yeah -- it's hard to talk about "laminates" as though they're all similar, when they aren't. Some are, indeed, cheap substitutes for solid wood, offering the ability to make really strong guitars via a relatively unmusical, non-toneful approach. On the other hand, some (few) builders are using laminates in a more purposeful way and may be arriving at a point where their results are good. In my experience, thus far, laminated wood instruments have ranged from pretty good to poor. But I don't feel that I can safely generalize and say they all stink because some makers are starting to come up with fine results. It's a transitional period for this method.

[Jaden]

With regard to laminate in the fine dimensions discussed here it certainly has the edge over solid wood in stiffness. Some manufacturers have figured out long ago to combine that stiffness with thin-ness and even the quality of brittleness which E. Somogyi talks about in its sonic reflective properties of ‘glassiness’ as in Brazilian rosewood.

[mercy]

I had a Martin dread with a lam back cause it was all I could spend but the tone was not there so I said to myself, "not again". Lam is good in certain places like the tail block or the sides. It may be that some builders know how to make lam work but not a factory guitar and I have to ask why. Solid sounds great, why lam?

[JohnW63]

Some quite nice guitars have a laminated back. Guild used to make arched back guitars with a big press ( Which I understand did make the cross country trek from Connecticut to California when Cordoba Music bought them ) for some of their hollow body guitars as well as some of the Maple guitars.

If you don't see a center brace, next to the label on a Guild, it's an arch back.

[Wade Hampton]

Griff, just to add to what’s already been mentioned, as a general rule a stiffer back will often contribute a “brighter” tone and a more projective instrument, while a solid wood back that isn’t as rigid will probably have more “warmth” and a bit more bass and lower midrange response.

One way to get that stiffer back is to use high quality laminates and press a gentle parabolic shape into the wood. There are a number of Guild guitars that have that feature. Another way to get a similar effect using all-solid wood construction is to use more back braces, which is what the Mossman Guitar Company did to get more projection and high end “bite” from their otherwise very Martin-like design.

As Todd wrote, the characteristic tone of the Martin D-35 comes not from its three piece back, but from its thinner top bracing.

Something you might find interesting is that many custom guitar builders are making four and sometimes even six piece backs, especially when using rare and costly woods like African blackwood and Madagascar rosewood. It can be impossible to find those woods in widths adequate for two piece backs, so they use what they can get.

And these multi-piece backs sound just fine. Skilled builders can get whatever tonal results they’re after when using them.

Hope that makes sense.


Wade Hampton Miller

[tadol]

And - stiffness, by itself, is not really a quality one wants in most guitars. It is one of a few different criteria that may be used to judge a piece of wood while building, but only to know what it is so the builder can figure out how to create the sound they want from the instrument they want to make -

There are a number of builders who do basically build a very rigid and solid box, that acts primarily as a frame to hold the top and the neck, and the top and the interior volume and dimensions of the box create most of the tone. For that style of construction, laminates or even molded plastics can be used for the back and sides. Then, other factors come into play -

But as stated, 3, 4, 5, or even 6 pc backs can easily be used to create great instruments, and to take advantage of really good wood that is otherwise unobtainable in the widths needed. In fact, with multi piece backs, you can actually get a much better, perfectly quartersawn back -

[Alan Carruth]

As Wade says, stiffness in a back lends a particular sound, which may or may not be what you want. Luthiers sometimes talk about 'relflective' (stiff and heavy) vs 'active' (looser and lighter) backs. It's not a strict dichotomy: the only really 'reflective' backed guitar I know of, where the back doesn't vibrate at all to speak of, is the Ovation. Usually they do vibrate some and it's a matter of degree.

There's laminate and laminate. Some high-end makers laminate sides with veneer layers that all run in pretty much the same direction. I think Ramirez was one of the first big makers to do that, using Brazilian rosewood on the outside and cypress inside. Cross laminates, like normal plywood, can have sufficient stiffness, but tend to end up a bit heavier and to have higher 'damping': they dissipate energy faster. This is not usually considered a good thing, particularly in the back, although it's hard to point to the exact influence on the tone. Cross laminations in the top are pretty much confined to low-end guitars.

There is a type of construction, called a 'sandwich' or 'double' top, where thin layers of spruce, cedar, or redwood are glued to a spacer material; most often Nomex or, sometimes, foam plastic. This produces a sort of 'super wood', which has the same stiffness as a normal top but weighs significantly less. The object is to make a guitar that is both louder and more responsive than a normal instrument, and it can work pretty well in that respect. The jury is still out on whether there can be long-term structural problems with this. It's definitely a high-end method, though.

[jessupe]

Originally Posted by griff599

So, been pondering a little and thought the expertise here might have good thoughts. So we hear about solid backs over laminate, tonewood differences, and quality of laminate. What about solid backs that are more than two piece. Of course the D-35 comes to mind but really any guitar with a 3 piece back.

What effect would that have on tone as opposed to a solid 2 piece back. And while were at it, if stiffness is a quality that is wanted, couldn't some laminate be more stiff than solid.

thnx.

ericksson.jpg

Let alone a 26 piece balsa braced arched back, oh my!

[Pitar]

This is a laminated back of varying contrasting species by Ervin Somogyi. Not solid by any stretch. But, he still manages to craft a sound from this box that is sought by those who can afford to own it (sound, that is). Laminate has not prompted a negative opinion of its use from this builder.

[Misifus]

Also, I have seen and heard guitars from several luthiers made from as many as four narrow strips of solid wood, edge joined, somewhat like bookmatched repeated. These guitars have been excellent with tone to die for.

[Alan Carruth]

If you look closely, you'll see that the back on that Somogyi is actually two pieces with a complicated inlay. You can follow the 'spider web' lines from one block to the next. It's even more obvious in a curly maple back.

At any rate, no matter how you do the back, most of the sound is it the top.