Using non-traditional or non-tropical woods

[perttime]

I missed the concerts at a local guitar festival - but made it to a presentation by a EU supported project "to study, demonstrate and communicate the opportunities of building acoustic guitars with non-tropical woods"
https://sites.google.com/site/leonardoguitarresearch/

The interesting part was the listening experiment. Antonio Forcione played 5 pairs of guitars, first behind a screen and then so that we were told, and could see, what he was playing. 5 luthiers had built the pairs: same layouts, same strings, different materials. The audience had sheets where we were marking which guitar from a pair we preferred and how big the difference was. (We didn't get the results yet)

After some questions and discussion, Antonio was given one pair to play again and he told us what he preferred and what he thought about that pair. From that pair of fairly large bodied guitars the one with birch sides, back and neck, suited him better: "well balanced, full sounding, sweet". The other one, a rosewood guitar, was obviously louder and had stronger high end and overtones. "If you are a strummer, this is the guitar".

Among the other pairs, I was surprised how similar the oak guitar sounded to its rosewood companion.

[Ned Milburn]

Antonio de Torres, long considered the father of the modern guitar, is reputed to have done an experiment where he built a guitar with paper mache sides & back to show the key importance of the soundboard to a guitar's tone. Apparently, it didn't sound much different than his all-wood guitars. Can't speak from experience, though, since I wasn't around back then. ;-)

[Alan Carruth]

IMO, the property of the back material that seems to make the most difference in the sound is the density. Some oak is as dense or denser than some BRW, and can sound very similar. Some makers consider African Blackwood, which can be 20% denser than water or maybe more, to be better than BRW. One of the biggest differences between Classical and Flamenco guitars in in the density of the 'usual' back woods, which can be very similar in other respects. I could go on.

[Ned Milburn]

Originally Posted by Alan Carruth

One of the biggest differences between Classical and Flamenco guitars in in the density of the 'usual' back woods, which can be very similar in other respects. I could go on.

Oh, but don't forget the lighter bracing, the lighter bridge, the lower bridge and lower saddle, the generally thinner body (smaller volume air cavity).

I like to think of whether the sides/back will "recirculate" the vibrating energy or absorb it (dampening). But again, this (sides/back combination) colors and shapes the sustain of the note, rather than its initial attack which resides mostly in the top.

[Trevor Gore]

Originally Posted by Ned Milburn

Antonio de Torres, long considered the father of the modern guitar, is reputed to have done an experiment where he built a guitar with paper mache sides & back to show the key importance of the soundboard to a guitar's tone. Apparently, it didn't sound much different than his all-wood guitars. Can't speak from experience, though, since I wasn't around back then. ;-)

Domingo Pratt, who was around at the time, described it like so:

"...this guitar has an extraordinary sound, if perhaps a little muted, bland and low, as the author of this dictionary was able to confirm when he played it in the house of Tarrega..."

I wouldn't be calling that a ringing endorsement...(or we'd all be building "muted, bland and low" guitars!)

As Alan said, back wood density makes a difference, but I'm more inclined to assign the difference to the overall mass of the "chassis", where a dense wood makes for a heavier chassis. Cutting a very long story short (and so missing a lot of important detail) heavy guitars with light tops are generally louder than light guitars with the equivalent top.

If you want "chapter and verse" I could recommend a good book which has the testing and modelling fully documented.

[Dan of SC]

People usually mean back and sides when they say "tonewood". Some say that the whole idea of tone wood is a hoax. It does seem to me that the topwood is more important than sides and back. On the other hand, I do know that virtually all wooden marimbas are made with rosewood. Apparently nothing else rings like it when struck with a hammer. Then again a guitar is not a marimba and you don't strike the sides and back of a guitar. I built a guitar with American cherry sides, back and neck, sitka top. I finished it with spray can lacquer from Home Depot. Sounded pretty good. About a year and a half later, I sanded the finish off and sprayed it with Behlen Stringed Instrument Lacquer. It not only looked better, the tone was way better. Seems many things can affect tone. I recently finished building an identical guitar with Honduran mahogany sides, back and neck, sitka top. (The mahogany came from a huge door built around 1980). I don't believe that blindfolded I can tell the difference in tone of these two guitars. IMHO, I say leave the rainforests alone and find alternative ways to make a nice sounding guitar. It's a matter of priorities. Thanks for reading, Danny Gray

[Alan Carruth]

In theory, wood that 'rings' fora long time when you tap it should make a guitar with lower losses. In practice, of course, the losses are only incurred when the wood vibrates. Dense wood is harder to get moving, and so should lose less energy in vibration.

Of course there are many differences between Classical and Flamenco guitars other than the wood in the B&S. These differences also contribute to the characteristic timbre. However, a 'Flamenca Negra' that is made of rosewood in exactly the same way as a 'blanca' of Cypress won't sound the same. Cypress has very low damping, like rosewood, and good stiffness for it's density, possibly even as high as rosewood on a volumetric basis (I don't have enough measurements to say with any confidence, but am going on what I've seen in other softwoods); the main difference is the density. It's likely that cypress was used originally because it's the 'local' wood, and hence less expensive: Flamencos have historically been impecunious. The fact that it worked well to produce the desired timbre lead to further refinement of other features along the same lines and produced a specialized Flamenco instrument where there had been only one 'guitar', if my reading of the history is correct.

[Kitchen Guitars]

Tim McKnight used my requested Tiger Striped Oak with no hesitation for this build he did for me. She sounds as beautiful as she looks. Top wood is Carpathian. It was built for responsive fingerstyle, medium decay. On the money.

[John Arnold]

People usually mean back and sides when they say "tonewood".

The first thing I think of when I hear that term is soundboard wood.

[Ben-Had]

And I think of both, so there you have it

[charles Tauber]

Originally Posted by John Arnold

The first thing I think of when I hear that term is soundboard wood.

the first thing I think of is marketing.

Any wood that someone has used twice in making instruments is a "tonewood". If someone used it once and didn't like it, they didn't use it again. So many different woods have been used that it isn't much of a distinguisher: the term "tonewood" becomes meaningless since it includes such a large number of woods.

[runamuck]

Originally Posted by charles Tauber

the first thing I think of is marketing.

Any wood that someone has used twice in making instruments is a "tonewood". If someone used it once and didn't like it, they didn't use it again. So many different woods have been used that it isn't much of a distinguisher: the term "tonewood" becomes meaningless since it includes such a large number of woods.

Charles,

More and more I appreciate your take on things.



Jim McCarthy

[Archtop Guy]

One mix of non-tropical woods has been standard for quite a while: maple and spruce. Maybe violin and archtop makers are on to something!

[perttime]

Originally Posted by Archtop Guy

One mix of non-tropical woods has been standard for quite a while: maple and spruce. Maybe violin and archtop makers are on to something!

I've heard some maple and spruce flat top guitars, and liked them very much - and my spruce and birch guitar isn't bad.

For the listening experiment that I mentioned in the first post, I think the guitar pairs were built by student luthiers for their graduation project. The task was to build one in "traditional" woods and one in "domestic" (Finnish) woods. I found a couple of those guys on facebook:
The "rosewood and oak pair" by Hemmo Honkonen
My favorite pair by Antti Kokkonen: cedar, American maple, ebony (not sure about neck wood); and spruce, flame birch, and elm.

The "non-tropical woods project" will apparently release data and videos of the listening evaluations (and more?) some time during the autumn. They have done similar sessions at other events too.

[redir]

Originally Posted by Kitchen Guitars

Tim McKnight used my requested Tiger Striped Oak with no hesitation for this build he did for me. She sounds as beautiful as she looks. Top wood is Carpathian. It was built for responsive fingerstyle, medium decay. On the money.

That's quite a beauty there. The last guitar I built was out of oak and I love it. Love working with it, love the way it looks, love the way the guitar sounds. In fact I probably play this guitar more than any one of my others. This pic the guitar is leaning against the barn from which she came.



I still have a huge stash of this wood that I plan on using in the future. I also like to use walnut, cherry and maple.

I think luthiers know that our local domestic materials can be used to build just as nice a guitar as one from the exotics but unfortunate the general guitar playing public has their own idea of what makes a good guitar. There is a niche out there though that appreciates the 'greenness' of a locally built locally sourced guitar.