Does soundbox tension affect volume and tone

Dwain Wilder
Dwain Wilder
@dwain-wilder
one month ago
61 posts

Ken Longfield:

Dwain, Don Kawalek is also a vendor at Pocono this year. Although not known as a dulcimer builder he has been making guitars, banjos, and mandolins for many years. He worked for a guitar builder in New Jersey for a while and then went on to become a shop teacher in northern Virginia. I don't know if he does any repair work. I met him when I took a week long banjo making class from him.

Ken

"The dulcimer sings a sweet song."

 

Ah! I missed seeing Kawalek. I think I met him at last year's Nutmeg Festival, in Milford, CT. Fantastic work, and a very unassuming guy. When I asked him where he hailed from he said "I live in West Virginia, under a rock."

Ken Longfield
Ken Longfield
@ken-longfield
one month ago
1,097 posts

Dwain, Don Kawalek is also a vendor at Pocono this year. Although not known as a dulcimer builder he has been making guitars, banjos, and mandolins for many years. He worked for a guitar builder in New Jersey for a while and then went on to become a shop teacher in northern Virginia. I don't know if he does any repair work. I met him when I took a week long banjo making class from him.

Ken

"The dulcimer sings a sweet song."

Dwain Wilder
Dwain Wilder
@dwain-wilder
one month ago
61 posts

Matt Berg:

Dwain,

Are you talking about the Pocono Dulcimer Festival?  It is a full day drive from Michigan, but a workshop where builders talk sounds fascinating.

Have you had these workshops before.  Who shows up, what day will it be?

Matt

 

Yes, the Pocono. I really appreciate your interest and willingness to consider the journey!

I'll be teaching a workshop on how to repair cracks in any surface of the body of a music instrument, including gluing in cleats across the crack, entirely from outside the instrument, using a soundhole for passing in the cleats and interior clamping gear. The workshop is listed as "Laparoscopic Crack Repair." Saturday, 9-10:15

There will be plenty of time to talk with me (unless people bring a lot of cracks to be repaired, extra fret installations and other refit/repair work) and the other builders there and exchange techniques, views on effective design, finishes, etc. Currently, David Fox, Bernd Krause and Gerry Heinrich are the other dulcimer builders registered as vendors. And as Ken mentions, he will be there for this workshop. Looking forward to visiting with you, Ken!


updated by @dwain-wilder: 04/14/24 02:44:25PM
Ken Longfield
Ken Longfield
@ken-longfield
one month ago
1,097 posts

I am signed up for Dwain's workshop. The nice thing about the Pocono festival is that you can sign up for individual workshops rather than for the entire festival. Looking forward to seeing you at the end of the month Dwain.

Ken

"The dulcimer sings a sweet song."

Matt Berg
Matt Berg
@matt-berg
one month ago
93 posts

Dwain,

Are you talking about the Pocono Dulcimer Festival?  It is a full day drive from Michigan, but a workshop where builders talk sounds fascinating.

Have you had these workshops before.  Who shows up, what day will it be?

Matt

Dwain Wilder
Dwain Wilder
@dwain-wilder
one month ago
61 posts

Dusty Turtle:


The direction of this discussion exemplifies why Nate's original question is so hard to answer: there are a lot of variables.  He started out asking if modifying the way the strings attached to the dulcimer might increase the tension of the soundboard, thus increasing volume.   But the conversation moved on to the tension of the strings themselves and now how the fretboard is attached to the body of the dulcimer.  The "floating" tailpiece or, as David Beed calls it, the " decoupled tailpiece " surely affects the tension of the soundboard, but more importantly, by reducing its contact with the soundboard, it frees the soundboard to vibrate more, which changes both the volume and the timber of the dulcimer.  Again, that is adding another variable to the equation. Dwain and John mentioned bracing and sound posts, which add even more variables to consider


I am not a builder, and I haven't studied physics since high school, so I might be way off base here.  But I wonder if the issue is not the whether tension increases or decreases volume, but where the Goldilocks sweet spot is.  On guitars, too little or too much bracing will reduce the responsiveness of the instrument.  On a dulcimer, I presume, too much or too little tension (or stiffness of the wood) would not produce sufficient volume. If we were to map out the relationship between tension and volume, the result might not be a straight line, but something resembling a parabolic arc.



 


A good summation, Dusty. It is much easier to have such a discussion about a music instrument with strict conventions such as the violin family of instruments. But even there it eventually defies mere words to show how to make a great instrument.


And fretted instrument builders are constantly innovating, experimenting and analyzing, with a huge range of effect (both desirable and miserable). I've heard that sound posts can deaden a dulcimer from several who tried, and here we read of two luthiers who got a success with them in dulcimers, one even defining exactly where to position the two sound posts!


That constant exploration creates a rich field of personal experience and deep knowledge, but it is not analytical knowledge one would expect from following scientific method. On the other hand, scientific method and analysis will yield any amount of numerical data on a musical instrument, but none of those numbers will tell you anything about what makes it a good instrument or a poor one.


Much better than analytical method is the experiential method, otherwise known as the heuristic. Using the heuristic method is simply making an educated guess that some design change will make a certain desired difference. So one builds an instrument with that one specific change and assesses the results of the guess. If it seems to have worked, build 9 more instruments identically as possible and see if your result is repeatable. If not, dead end alley. But if the effect you wanted is found then try making 10 instruments with a little less of your change and 10 made with an accentuation of your change and see which direction, if any, seems headed more toward your 'goldilocks' point.


It is a very slow process, but it is evidence-based in a way that numerical analysis never is. And the longer you follow your intuition, the better it becomes at a deep but ultimately black art that one cannot write out as a rational explanation but can easily teach, in person. to a student who wants to learn by first-hand experience. It's all like learning how to sharpen a cabinet scraper properly so it will scrape a curl off a plank of redwood without tearing the grain. One can spend a decade learning that unless one has a tearcher, and most of what one learns is in the final year (ask me how I know that...). That's what 'black art' means to me: something I can show someone how to do, but they will not be able to do it from my verbal description, no matter how fine a description it is.


That makes these kinds of forums rather like rumpus rooms, each of us speaking from our own understanding of our craft but rarely meeting in a setting where we could actually demonstrate the validity of what we are saying.


Festivals would be a good place for dulcimer builders to hold workshops for each other. I'll be holding one in a festival soon, at East Stroudsburg, PA, later in April


updated by @dwain-wilder: 04/14/24 03:11:59AM
Dusty Turtle
Dusty Turtle
@dusty
one month ago
1,732 posts

The direction of this discussion exemplifies why Nate's original question is so hard to answer: there are a lot of variables.  He started out asking if modifying the way the strings attached to the dulcimer might increase the tension of the soundboard, thus increasing volume.   But the conversation moved on to the tension of the strings themselves and now how the fretboard is attached to the body of the dulcimer.  The "floating" tailpiece or, as David Beed calls it, the " decoupled tailpiece " surely affects the tension of the soundboard, but more importantly, by reducing its contact with the soundboard, it frees the soundboard to vibrate more, which changes both the volume and the timber of the dulcimer.  Again, that is adding another variable to the equation. Dwain and John mentioned bracing and sound posts, which add even more variables to consider

I am not a builder, and I haven't studied physics since high school, so I might be way off base here.  But I wonder if the issue is not the whether tension increases or decreases volume, but where the Goldilocks sweet spot is.  On guitars, too little or too much bracing will reduce the responsiveness of the instrument.  On a dulcimer, I presume, too much or too little tension (or stiffness of the wood) would not produce sufficient volume. If we were to map out the relationship between tension and volume, the result might not be a straight line, but something resembling a parabolic arc.




--
Dusty T., Northern California
Site Moderator

As a musician, you have to keep one foot back in the past and one foot forward into the future.
-- Dizzy Gillespie
Strumelia
Strumelia
@strumelia
one month ago
2,263 posts

Yes my Keith Young dulcimer has that fretboard. (see the FOTMD logo at top of this site for a pick of that dulcimer)  Keith used to call it a 'floating tailpiece' I believe.
Randy, agreed it is a bit tricky to catch the loop ends over the brads underneath. I found that bending the string end slightly beforehand helped a lot.




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Site Owner

Those irritated by grain of sand best avoid beach.
-Strumelia proverb c.1990
Robin Thompson
Robin Thompson
@robin-thompson
one month ago
1,437 posts

This fretboard design, though somewhat different, is reminiscent of Keith Young's: 

https://www.newharmonydulcimers.com

NateBuildsToys
NateBuildsToys
@nate
one month ago
252 posts

Thank you Ken Dan Robin and Randy for the information, I suspect that investigating these designs will provide me with useful information

Randy Adams
Randy Adams
@randy-adams
one month ago
115 posts

You an me gots esp er something Robin. : ) jinx!

Edited to show Ben Seymour he shows view of cantilevered fingerboard look quick!


updated by @randy-adams: 04/13/24 11:10:18AM
Randy Adams
Randy Adams
@randy-adams
one month ago
115 posts

Nate I had a Keith Young dulcimer had a cantilevered fingerboard maybe 3-4" before end block was a bitch to change strings brads were on under side between fingerboard and the top.

Beautiful tone and big bass. No conclusions here though. 

Construction industry has examples of installed tension for strength and resistance. 

Robin Thompson
Robin Thompson
@robin-thompson
one month ago
1,437 posts

NateBuildsToys:

A while ago on here I saw a dulcimer that had gap under the tail end of the fingerboard, with the string tension pulling it up from the box. The idea was that by having the tail end of the fingerboard (where the strings were mounted) detached from the box, the string tension would pull hard on the area with the string pins, lifting it so that it hovers a couple millimeters above the soundboard potentially increasing volume. Does anyone know what this feature is called, so I can look into it more?

 

Makes me think of Keith Young's fretboards.  I think I don't have any photos of the end of the fretboard-- I used to have 2 of Keith's wonderful instruments.  

Dan
Dan
@dan
one month ago
185 posts

NateBuildsToys:

A while ago on here I saw a dulcimer that had gap under the tail end of the fingerboard, with the string tension pulling it up from the box. The idea was that by having the tail end of the fingerboard (where the strings were mounted) detached from the box, the string tension would pull hard on the area with the string pins, lifting it so that it hovers a couple millimeters above the soundboard potentially increasing volume. Does anyone know what this feature is called, so I can look into it more?

 

David Beede "de-coupled" tailpiece
Matt Berg
Matt Berg
@matt-berg
one month ago
93 posts

John,  I did build one dulcimer with a sound post.  both the back and sound board were rounded, it had a floating fretboard that sat on a bridge under the saddle and fretboard.  The instrument did  have good volume and sound.  For a variety of reason, I have move away from rounded soundboards and haven't built another instrument with a sound post.  (The sound post is used to give stability to the sound board against the string tension.  It also transmits vibration to the back.  I tried this to increase the sound coming from the bottom of the instrument, a way of enhancing instruments with a false bottom.)  Matt

Ken Longfield
Ken Longfield
@ken-longfield
one month ago
1,097 posts

John Petry:

Having set up many violins & cellos etc over the years....You may want to explore using a sound post. Not really a "dulcimer" thing, but you're an outside the box kinda guy anyway. If you Google "adjustable soundposts" you will find much info good and bad about using them in so- called "real" instruments... Bottom line, is that moving the amount and location of tension to the vibrating surfaces [top and bottom] can and does change the tonal qualities. I suggest an adjustable only because there are no standard rules when it comes to dulcimers and the dimensions. Instead of having to re mount your strings, an adjustable may give you more room to play around, or just source some dowel rod and have at it..[or pencils, chopsticks,...] Changing the tensions to the body and try and find the "sweet" spot[s] if any? Then we'll have to find out if heart holes with pointy bottoms sound as good as rounded ones......

just the meanderings of a wandering mind......

 

While the sound post may not be "a dulcimer thing," two old time dulcimer makers, James Edward Thomas and Charles Napoleon Prichard, used sound posts. In the case of Thomas, he actually used two; one at the 3rd fret and one at the 10th fret. Prichard's was in the middle of the fret board half way between the scroll end and the tail end of the dulcimer. Both used staples rather than modern frets. 

A friend of mine who was building reproductions of the Prichard dulcimer did not know that Prichard used a sound post. After I told him about the sound post and its placement he said it made a substantial difference in the volume of this instruments.

Ken

"The dulcimer sings a sweet song."


updated by @ken-longfield: 04/13/24 10:51:45AM
Ken Longfield
Ken Longfield
@ken-longfield
one month ago
1,097 posts

Nate, when I built my first dulcimer the end of the fret board was cantilevered. That was the what the plans I was using called for. The plans were designed by Joseph Wallo who worked in Weaver's Violin Shop in Washington, D.C. It is the shown in the bottom photo of this post.

I have added another photo of a courting dulcimer I built for a friend and both fret boards have cantilevered ends.

My first dulcimer is now fifty years old, been under string tension that entire time (tuned DAA), and has not warped. I don't know how the courting dulcimer faired, but it is only 47 years old.

Ken

"The dulcimer sings a sweet song."

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updated by @ken-longfield: 04/12/24 10:44:24PM
Ken Hulme
Ken Hulme
@ken-hulme
one month ago
2,126 posts

That slot at the tail end of the fretboard was, IIRC, a Howie Mitchell "thing".  Not sure it ever worked as advertised.  

NateBuildsToys
NateBuildsToys
@nate
one month ago
252 posts

A while ago on here I saw a dulcimer that had gap under the tail end of the fingerboard, with the string tension pulling it up from the box. The idea was that by having the tail end of the fingerboard (where the strings were mounted) detached from the box, the string tension would pull hard on the area with the string pins, lifting it so that it hovers a couple millimeters above the soundboard potentially increasing volume. Does anyone know what this feature is called, so I can look into it more?


updated by @nate: 04/12/24 07:56:07PM
NateBuildsToys
NateBuildsToys
@nate
one month ago
252 posts

John Petry:

Having set up many violins & cellos etc over the years....You may want to explore using a sound post. Not really a "dulcimer" thing, but you're an outside the box kinda guy anyway. If you Google "adjustable soundposts" you will find much info good and bad about using them in so- called "real" instruments... Bottom line, is that moving the amount and location of tension to the vibrating surfaces [top and bottom] can and does change the tonal qualities. I suggest an adjustable only because there are no standard rules when it comes to dulcimers and the dimensions. Instead of having to re mount your strings, an adjustable may give you more room to play around, or just source some dowel rod and have at it..[or pencils, chopsticks,...] Changing the tensions to the body and try and find the "sweet" spot[s] if any? Then we'll have to find out if heart holes with pointy bottoms sound as good as rounded ones......

just the meanderings of a wandering mind......

 
John that's very insightful. I have built a few dulcimers with various soundposts, but hadn't thought about how some of that information can be applied to this question. Thanks for the food for thought.

NateBuildsToys
NateBuildsToys
@nate
one month ago
252 posts

Ken Hulme:

I think if you had half of the string tension pulling up and half the string tension pushing down, the result is not increased tension but rather a neutralized/balance of tension not helping at all...

 
Ken, I think you may be right about that. My hope is that the forces won't exactly be "balanced" but opposing. That by pulling and pushing, the entire area would become much more rigid, and possibly more responsive. 

My other main question is: if I shouldn't go half and half, what arrangement is optimal? All strings mounted to the fingerboard? All strings mounted to the box. I suspect that mounting them to the fingerboard rather than a tailpiece may produce more volume.

John Petry
John Petry
@john-petry
one month ago
11 posts

Having set up many violins & cellos etc over the years....You may want to explore using a sound post. Not really a "dulcimer" thing, but you're an outside the box kinda guy anyway. If you Google "adjustable soundposts" you will find much info good and bad about using them in so- called "real" instruments... Bottom line, is that moving the amount and location of tension to the vibrating surfaces [top and bottom] can and does change the tonal qualities. I suggest an adjustable only because there are no standard rules when it comes to dulcimers and the dimensions. Instead of having to re mount your strings, an adjustable may give you more room to play around, or just source some dowel rod and have at it..[or pencils, chopsticks,...] Changing the tensions to the body and try and find the "sweet" spot[s] if any? Then we'll have to find out if heart holes with pointy bottoms sound as good as rounded ones......

just the meanderings of a wandering mind......

Ken Hulme
Ken Hulme
@ken-hulme
one month ago
2,126 posts

I think if you had half of the string tension pulling up and half the string tension pushing down, the result is not increased tension but rather a neutralized/balance of tension not helping at all...

NateBuildsToys
NateBuildsToys
@nate
one month ago
252 posts

I am trying to ask about how to utilize the string tension to put the box under extra pressure, and if this can be good for tone or volume.

Here is a drawing that hopefully helps explainoriginal

Let's assume the dulcimers have identical dimensions and the same break angle, and the only difference is whether they are mounted to the fingerboard or the box.

In figure A, when the strings are anchored to the fingerboard, the 60-100 pounds of string tension should be trying to pry the fingerboard up off the box. I am wondering if this "pulling" is adding extra stress and tension to the box, and if having the wood under more stresses makes it more rigid and stiff and allows it to transmit vibration better.

In figure B, when the strings are anchored to the side of the box, the 60-100 pounds of string tension is laying across the end of the fingerboard, pushing it down into the top of the box. I am also wondering if this improves overall responsiveness of the instrument, by distributing that 'pulling force" across the tailpiece into the side panels. 

I hypothesize that if you could mount half your strings to a tailpiece and the other half to the fingerboard, the forces would be pulling the fingerboard up while also pushing it down, adding a huge amount of stress to it, possibly making it more stiff and responsive.


updated by @nate: 04/11/24 12:41:49PM
Dwain Wilder
Dwain Wilder
@dwain-wilder
one month ago
61 posts

NateBuildsToys:


Hey folks, this question might be poorly asked but here goes.


Does a soundbox that is under more tension have any additional clarity or additional volume? Is this the reason that 'lighter' builds are more responsive?


When I think about a musical saw, the volume seems to directly correspond to the amount of tension out on the saw blade.


Similarly, a washtub bass seems to be quite a bit louder on its high pitched notes, when the string is pulling the hardest on the tub.


I have been thinking a lot about where the strings are anchored on my dulcimers. Anchoring them to the fingerboard should apply an upward 'pulling' force on the area of the fingerboard with the pins. Meanwhile if the pins are anchored on an actual tailpiece of the box, they are stretched across the end of the fingerboard and are 'pushing' it down into the soundboard.


Does one of these produce more resonance than the other? 


original


Here is a picture of a test dulcimer I built where the strings can be mounted to either the box or the fingerboard. (Sorry it's a bit ugly, form follows function) I am thinking of mounting both outer strings to the fingerboard, and the middle string to the box. My speculation is that this will put a huge amount of extra tension on the fingerboard, and the middle string will help prevent the fingerboard from being pulled off the soundboard. sadly I can't test this out until the local music shop opens back up in a few days.


Any information of how much tension matters, and how to properly harness that would be greatly appreciated



I am unclear about whether you are talking about string tension itself, the effect of string tension when mounted on the fretboard or the instrument body, or a wider question about the effects of tension on the instrument.


If you are talking about the effect of strings mounted on the fretboard, yes, it does has an effect. The effect is almost entirely lateral (depending on how high the play action is), and will be considerable if the fretboard is attached with ordinary woodworker's glue (aliphatic resin, 'yellow glue), unless it is stopped by the peghead (in which case the stress is transferred to a considerable degree to the joint of the peghead to the body (I had one dulcimer fail due to the accumulated stress on a peghead that had a hidden internal wood flaw).


The matter of string stress on the body of the instrument is a much more complex matter, as it involves construction techniques, the internal bracing and stresses within the body, and the overall design shape and geometric details.

Ken Hulme
Ken Hulme
@ken-hulme
one month ago
2,126 posts

Matt/Nate -- that 15 degree break angle is very close to the commonly-used-in-dulcimer-builds 12 degree break angle of strings from the nut to the tuners, and from the bridge to where the strings break hard over the back of the fretboard.  Dulcimers with sharper break angles, especially at the tail seem, qualitatively anyway, to have more volume.  I'm thinking of those which have the bridge set all the way to the rear so the strings drop almost 90 degrees to the string pins in the tailblock.

Strumelia
Strumelia
@strumelia
one month ago
2,263 posts

I recall others posting in the past about how increasing string tension (either by tuning higher, or simply by putting on heavier strings) on dulcimers added volume.

I do know that on banjos if you increase tension you will get more volume... but there is a point of diminishing returns, and when you reach it the sound suddenly becomes more tinny. I have seen this. And more volume does not necessarily mean more resonance or a 'better' sound.
On banjos, more string tension can be achieved by: heavier strings / higher tuning / tightening the skin head / tightening down the tailpiece that presses the strings down / putting on a higher bridge.
Supposedly, Earl Scruggs was once asked how tight to adjust the skin head tension on a bluegrass banjo banjo, and he said "Crank it down it just until the head splits, then back off a little."  bigsmile




--
Site Owner

Those irritated by grain of sand best avoid beach.
-Strumelia proverb c.1990

updated by @strumelia: 04/10/24 06:44:07AM
Matt Berg
Matt Berg
@matt-berg
one month ago
93 posts

Nate,

A few years back American Lutherie had an article about someone trying a similar experiment with jazz guitars.  Jazz guitars have the strings stretched over the sound board, similar to dulcimers, not attached to the soundboard like most guitars.  In the article, the angle of the string from the saddle to the tailpiece was adjusted from near zero the almost 45 degrees.  In this experiment, the volume (quantitative) increased as the angle decreased, but the tone (qualitative) decreased as the angle decreased.  The writer settled on 15 degrees as the optimum angle.  I have tried similar saddle to tailpiece angles with my floating fret board dulcimers with similar results.

Matt

NateBuildsToys
NateBuildsToys
@nate
2 months ago
252 posts

Hey folks, this question might be poorly asked but here goes.

Does a soundbox that is under more tension have any additional clarity or additional volume? Is this the reason that 'lighter' builds are more responsive?

When I think about a musical saw, the volume seems to directly correspond to the amount of tension out on the saw blade.

Similarly, a washtub bass seems to be quite a bit louder on its high pitched notes, when the string is pulling the hardest on the tub.

I have been thinking a lot about where the strings are anchored on my dulcimers. Anchoring them to the fingerboard should apply an upward 'pulling' force on the area of the fingerboard with the pins. Meanwhile if the pins are anchored on an actual tailpiece of the box, they are stretched across the end of the fingerboard and are 'pushing' it down into the soundboard.

Does one of these produce more resonance than the other? 

original

Here is a picture of a test dulcimer I built where the strings can be mounted to either the box or the fingerboard. (Sorry it's a bit ugly, form follows function) I am thinking of mounting both outer strings to the fingerboard, and the middle string to the box. My speculation is that this will put a huge amount of extra tension on the fingerboard, and the middle string will help prevent the fingerboard from being pulled off the soundboard. sadly I can't test this out until the local music shop opens back up in a few days.

Any information of how much tension matters, and how to properly harness that would be greatly appreciated


updated by @nate: 04/09/24 03:54:26PM