Alternative Soundboard Woods

Per Samuelsson - 09:33am Nov 20, 1997

Hi!
I have some good looking pieces of walnut at home wich i think would look great on a steelstringed acoustic gultar. I wonder if anyone have any acoustic experince of that kind of wood ? Do you think it will work ?

Hello Per and welcome to mimf.

Instinct tells me that walnut would be to hard and dense for a soundboard but I have no experience to go on. There are several here who sing the praises of walnut for backs and sides of guitars, especially the Claro which grows in the western US. Lance, what do you think about using it for a top? It would be pretty, thats for sure.

Yes, I have an opinion on this (G). Actually, I've played a guitar with a walnut top. Breedlove has made them. I thought the guitar was phenomenal sounding, and I intend to do one when I get the chance. Now, here's the sticky wicket in regards to using tops and backs and sides all from the same type wood. If the top creates a tone or frequency that it resonates at, and the back resonates at that same frequency, you will end up with a cancellation of certain overtones and harmonics. Also known as wolf notes. This happens a lot in violins, cellos, and instruments of that sort because of the constant tone created by the bow and that the top and back are coupled together with a sound post. So, if one were to build out of same materials, one way to hopefully to stop this from happening would be to thickness the top and the back differently so hopefully they would end up with different tap tones. Or build them out of completely different pieces of walnut from different trees. But my thought about building a guitar with a walnut top, because it has such warm overtones, would be to match it with something like Brazilian, Pau Fero, Gonsalo Avles, or something that has a high ringing tap tone. Same theory as why Engleman spruce and Brazilian sound so good together. The top helps to warm up the sterile qualities of Brazilian. Hope this helps. Let me know if anybody gets to it before I do.

Giltay deduced in the 1920s that the function of the soundpost is to define a node, rather than to "couple" the vibrations of the soundboard to those of the back. Experiments since then have largely shown Giltay to be correct. There was an article in the CAS Journal this year showing that the soundpost is, if not exactly on a node, at least very close to one. Also, I thought that a "wolf note" resulted from constructive interference of certain frequencies rather than destructive interference ("cancellation"). Back to the point of this discussion, If overall stiffness of a soundboard is what matters, then a way can probably be found to use walnut, as well as graphite, spruce, etc., etc., effectively as a soundboard. If Breedlove made one nice guitar with a walnut soundboard, practice and experience should ultimately result in more nice guitars with walnut soundboards.

Lance,
That is very encouraging for the walnut soundboard. Like Dave says, probably many different woods could be engineered to work more or less well. By the same token, I think same species of wood in top and back is the least factor in creating the same tap tone and the additive effect that produces the wolf tone. There are so many differences in the way they are constructed, and what forces are applied to them, that arriving at the same tap tone (or what ever sameness causes the wolf tone) is by coincidence and pretty much unrelated to the wood itself or any other single factor.

Today harps almost allways have either spruce or redwood soundboards, depending on the sound you are after. Sitka spruce will give you a brighter sound where Engleman spruce or that nice european spruce will give you a softer mellower tone. (This is the reason for the difference in tone between Lion & Healey and Silva harps) Redwood has a nice soft worm tone, but is used generally on smaller harps with fairly low string tension. All will have a hard maple or equiv string rib to bare the string tension load. Hardwood soundboards are usually reserved for wire strung harps since the string tension is so much higher for these instruments. By the way, all of the old triditional Irish harps were wire strung. It wasn't until the middle ages that they switched to gut strings. The technique for playing the wire strung instruments was allmost lost. What a shame that would have been!
Dale

This is also a bit off of the subject, but what about using different woods for the sides and for the back? This is visually satisfying and makes for all kinds of speculation as to the effect on the sound. I would be interested in this speculation (and in actual experience as well!).

WOW! This discussion is kind of blowing me away!

I'm new at insturment building, but nearly everything I've read STRICTLY recommends only spruce or cedar as a soundboard. Now I'm hearing walnut as a "great" soundboard material.

Sounds great to me! I'd like to use woods I can acquire locally rather than paying the high price of mail order woods. And spruce has never been my favorite wood to work with or look at.

I don't know if this is any consideration, but some years back I built some dulcimers from solid cherry, some from solid walnut and ONE with all walnut but a very nice spruce top. I really couldn't tell much difference between the wanlnut and spruce top. Maybe on a dulicmer it doesn't matter as much? Or I didn't listen too closely?

I'd certainly like to hear from someone who has made an "identical" (or close) guitar with a spruce and a walnut soundboard.

P.S. I saw in the LMI handbook the "pallet" guitar Taylor made. Does this kind of negate most of the luthier "traditions, theories and preferences" to various woods? I'm wondering of we're letting tradition and opinions keeping us from building some beautiful looking and sounding instruments? To me, walnut is much better looking, easier and more reliable to work with than spruce.

Good discussion! I hope it keeps going! And I hope some of you veteran luthiers will try a walnut soundboard.

Harps use spruce soundboards because although total string tension is very high, individual string tension is fairly light, and spruce is the most responsive wood we can use for these instruments and still provide a degree of structural integrety. Each type of instrument will have different requirements to get what is considered good tone. Some of the fiddle makers I have met and talked to rate sitka spruce on a even par with CDX ply wood. I made a wire strung harp with a soundboard made out of purple heart. Sounded great and the customer won't part with it. (good thing, cause I'll never make another)

Are there other than triditional woods for soundboards for a particular instrument? You bet! But, who is going to expirment with different woods when you have deposit in your hand and orders to fill? I did try berch for a sound board once. After 4 days the harp self distructed at about 3:00 am, and it took three days to get the cat off the celing!

With todays glut on the good wood, and scarce sources not to mention prices, its only a matter of time until we are all playing arround with some new plastic composit materials (yuch!!! plastic).

When i posted the question about walnut in soundboards i was hoping to get one or a couple answer, i got more answer and information than i could think of - thank you!!!

Now i got a lot of tips, and also now i know some of the problems that hardwood in soundboards can bring. I don´t really know for sure if the walnut will work, but this discussion really got me so curios and inspirated that i´m going to try it out.

Here in Sweden are there just a few luthiers, and there are even less i can ask.

See you - I´ll be back
Per Samuelsson
Sweden

Another ingredient into the mix - with most types of walnut that I know of, you'll need to fill pores in the grain if you want a nice smooth finish...

Has anybody experimented with Douglas Fir for soundboards? I made one small-bodied 12-fret guitar 10 years ago with it with mixed results. It had a very loud, hard, piercing sound ideally suited to single string picking but too jangly for chordal stuff IMO. Michael Dunn claims its his favorite guitar of mine, frankly I like spruce better. Its very stiff and available commercially in soundboard quality wood - or used to be - look for high quality "stair runners" at your local lumberyard. Its tight grain, perfectly quartered (probably to minimize warp and max out strength). Seems to split fairly easy when thin, harder than spruce, with a very loud responsive tap tone.

Bob,
A little off the subject, but I used piece of a resawn Fir stair runner for a soundbox in a grandfather clock that I built. The chime rods are hooked to a small cast iron deal that I mounted on this soundbox. It amplifies the sound somewhat. I didn't want to spend money on expensive tonewood.

I got fancy and even cut 2 small "F" holes into the box.You can't even see it unless you open the door.(am I ate up with this hobby, or what?) This was the last woodworking project I did before starting my first acoustic guitar.

I'm completely hooked on guitar building now and am working on my 4th at the present time!
Jeff

Jeff,
My 4th guitar is still one of the best sounding I ever made. You never know when its all going to come together. Even though I have extensive notes on it I would'nt consider trying to 'duplicate' it. The pursuit of a new & better sound is more than half the fun.

Last year I used Alaska yellow cedar for a hammered dulcimer soundboard for the first time. Very fine grain, powerful as all get-out, rather harsh. Got it out again today to see how it had aged, and the harshness hasn't moderated much, if at all. Anyone else ever used it as a soundboard? It's quite the most poisonous smelling softwood I've ever worked with. I was looking for a substitute for Engleman spruce, and would probably call this acceptable.

The archtop I built a couple of years ago has atop of yellow cedar... I was deliberately using what was locally available, and found it at a local wood store. I don't know that I would call the smell 'poisonous', but it is definitely funky, and not very pleasant. The guitar itself has a good tone played softly or normally, but develops a dobro-like resonance when played hard - kinda weird for an archtop, but not bad sounding. I don't know how much of that is my initial attempt at graduating an archtop, use of parralel bracing, or the yellow cedar.

I bought a pile of red cedar for violin tops at a ridiculously low price, hoping for the best. Got the worst--loud and harsh. The have, however, turned out to make wonderful small sized violins, which I can't explain since small violins are pretty harsh on their own.

In my experience with hammered duclimers, from sweet to harsh;

sitka spruce
redwood
mahogany
western red cedar
Engleman spruce
Alaska yellow cedar

In addition to getting harsher as you go down the list, the ducimers also speak with a clearer voice.

I'm just finishing up a rebuild of a no-name parlour guitar, probably sold by Montgomery-Ward in the 20s. It has a solid mahogany back, sides, and top. The top is one piece and thicker than spruce would be , app. 5/32". It has lateral bracing only, quite heavy. The tone is excellent, well defined with long sustain. It is going to make a great instrument for finger-picking. The original construction was cheap, no truss rod so the neck was the classic banana shape when I got it. The original bridge plate was something like pine and was completely chewed up. The bridge was also made out of some anonymous wood. I replaced both with heavier (and harder) woods so it may have lost a bit of volume, but I'll have to see after a few months.

It may be that a mahogany soundboard works on smaller bodied guitars. I've had two Washburn Woodstocks (acoustic/electric with slightly arched tops) and the spruce top was much better sounding acoustically than the mahoghany,

I've noticed that some of the old fretted dulcimers had poplar tops; probably tulip poplar, rather thick (around 1/8") without any cross bracing. They aren't as bright or loud as the ones with thin, stiffly-braced spruce or cedar tops, but they have a very nice mellow tone, with much more of the fundamental and less of the harsh overtones. Has anyone ever tried tulip poplar?

Older fretted dulcimers were made out of whatever was handy. L. Allen Smith has written "A Catalogue of Pre-Revival Appalachian Dulcimers," a fun book for those of us who like to see photographs of musical instruments. Unfortunately the book doesn't include woods used in the index, but one instrument I happened to open the book to (not pictured) is mentioned as having a striped walnut/poplar soundboard, and a poplar back. The book is now out of print, but it was published in '83 and you can probably still find it somewhere...

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