Double Bottom Dulcimer?
 

I am building a dulcimer. In doing some research I’ve come across the term “double bottom.” Supposedly that allows the instrument to be louder.

Can someone explain to me how the construction of that works?

It's like a built in "possum board": it raises the bottom of the dulcimer itself from lap or table or wherever it's being rested so the sound isn't muffled (the sound escapes through slits or soundholes between the dulcimer bottom and the double bottom).

Here's what a possum board looks like:

https://www.folkcraft.com/products/t...-board-2317887

Imagine something like that actually being part of the dulcimer rather than an accessory:

https://bobgerarddulcimers.files.wor...87-m.jpg?w=663

Thanks very much!!! Will

https://i.postimg.cc/RFvw6bdm/P1130156.jpg

https://i.postimg.cc/CKGjKVjJ/P1130155.jpg

Galax dulcimers have been built with double bottoms for many years (possibly 100 years now). A dulcimer's soundboard is its bottom not its top, which is braced by the fretboard. So, traditionally, early mountain dulcimers would have had 3 little feet for playing on a table, keeping the bottom free to vibrate. And Galax dulcimer builders added the second bottom to achieve the same purpose when a dulcimer was played on the lap. These are loud instruments, played with a noter and quill, and strung to a good tension. A possum board will do a similar job for a contemporary instruments but modern playing styles of chord/melody out of DAd will never produce the volume of the older instruments and playing styles.

“A dulcimer's soundboard is its bottom not its top, which is braced by the fretboard.”

I never knew that. That is very interesting point. I am building a “Tennessee Music Box”, and I am hoping to get as much sound out of it as possible.

Thanks for the good information. Much appreciated!

Will

OK, soooo...why is it called a possum board?

Jack

Hi Will,

A Tennessee Music Box is a great project! As an experiment, I built one in a morning out of scrap wood. The story behind the project is here:

Box Dulcimer

Little feet on a TMB make a big difference to the sound, and ideally they should be played on a table rather than your lap. You certainly want a good tension in the strings - I would go for something like 8 gauge piano wire (0.020 plain steel) for the strings tuned all to the same note. Use 18 gauge wire for the staple frets (0.041) and I would set them in just intonation, pure diatonic, with the root note at the 3rd fret. I have a fret placement calculator for this if you send me a PM. You don't need thin fancy planking at all - thick pine will do the job. The 'trick' is to get the strings to generate enough energy to get the box humming along - so heavy strings wound up nice and tight do the trick.

Robin

What else could you possibly call it???? :D

A "Dulcimer-soundboard-back-raising-up-for-better-sound-thingie-dingie?" :lol:

Jack

Chromatic Scale
 

Ok, here’s one of those “I should know this by now questions”. The dulcimer I’m going to build will have a 26 inch scale length. I am familiar with fretting dulcimers using a diatonic method. But if I want to set it up to be played chromatically, is there a resource I can use to determine fret placement ? Is that just a matter of using something like the Stew Mac Fret calculator and entering the 26 inch scale length?

If you want it chromatic then just use the Stew Mac Fret calculator for guitar. Remember to set the bridge a little further away from the nut, by a 3mm or so, than the scale length you dial into the calculator. This is to allow for string stretch (intonation) as you play further up the fretboard. It is a good idea to make a reasonably wide bridge (say 1/8") so you can fine tune the strings release points and so adjust intonation.

I have to admit, that has a nice ring to it . . . ;)

Robin, your assertion that the back of a mountain dulcimer is its soundboard is true for European zithers like the concert zither made famous in “The Third Man,” and might also be true of Galax dulcimers, though I’ve never read that anywhere or heard it from any fellow dulcimer players in North America.

But it’s definitely not true of the mountain dulcimers built in the Ozark regions, like my native state of Missouri. With the dulcimers I grew up around and learned to play the top was definitely the soundboard. Especially as younger players like me took up the instrument and tried to expand its musical boundaries beginning in the 1970’s, the people building more progressive mountain dulcimers intended for serious players were trying to free up the tops more to let them vibrate better. You can see this in the designs of builders like Bonnie Carol and many others, particularly builders out in California, like the married couple Bob and Janita Baker, who make Blue Lion dulcimers, the brand I’ve been an endorser for and used onstage since 1983.

There’s definitely a school of thought centered around Galax, and “Galax tunings” do exist for fiddle and clawhammer banjo as well as mountain dulcimer. Prior to your post I had heard about double back dulcimer construction, but not in connection with Galax. However, they definitely have their own traditions and sense of style there. Most of the Galax dulcimers I’ve seen have been large teardrop shaped instruments, as opposed to the hourglass shape instruments that are much more popular where I’m from.

So I think we’re safe in attributing these differences to contrasting regional styles. But the soundboard being the back of mountain dulcimers hasn’t been true anywhere that I’ve lived. On the contrary, most of the serious players I’ve known have used instruments with spruce or cedar tops in order to get the richest, loudest, most sonically rich dulcimers we can get.

Hope that makes sense.


Wade Hampton Miller

Hi Wade,

We may be talking semantics here as the term 'soundboard' is not generally used in dulcimer making. But it is definitely the back of the instrument that is the major resonating surface. You can certainly use differing woods within the build of the top to adjust the tone, but it's freeing up the back to vibrate that makes the biggest difference - well that and actually fitting heavier strings! The top has a smaller free to vibrate surface area because of the fretboard and, unlike other instruments, the top is not directly 'driven' by the bridge (although some makers have tried out more guitar like designs by shortening the fretboard and placing the bridge on the top - with varying degrees of success).

You must be able to feel the back vibrating when you play? - those Blue Lion dulcimers are lovely, resonant instruments and if you move your legs a little further apart or angle a Blue Lion to play it like Stephen Seifert then they really open up in terms of tone and volume (or use a possum board). If you look through 'A Catalogue of Pre-Revival Appalachian Dulcimers' by L. Allen Smith you'd be surprised at the number of early mountain dulcimers from all regions - built to the same shapes today - that originally had little feet for table playing.

There was a great video made by the Australian dulcimer maker Richard Troughear where he makes a dulcimer with a paper top (which looks like a wood top) that he tears off half way though playing to show the effect of the top (or lack of effect) on sound. He has done extensive experiments on mountain dulcimer acoustics and we would often chat through his findings.

If you are interested in the history of dulcimer making in the Ozarks then look up John Mawhee and his descendants the Graves family (Bill and his son Don) I think have the longest tradition of dulcimer making in Missouri (John started making dulcimers just after the Civil War). John Mawhee's design was a very small teardrop about 5" wide and 32" long strung up with No8 piano wire (0.020 wire) and tuned high and tight to G,D,D - it has 3 little feet on it. I had one built, and played with a noter and whipped with a quill it is just about the loudest dulcimer I've played. They are perfect for an old time band setting and have 3 little feet for table playing. Both Bill and Don were fine players. Bill was a renowned Missouri fiddler and I have his Sugar in Coffee CD where he plays fiddle and the family dulcimers. Here is me playing a Mawhee dulcimer made by Kevin Messenger with the permission of the family:



The start of dulcimer making in California bought probably the most significant change the instrument had seen for hundreds of years - and that was the, most likely accidental, move to equal temperament fretting. Makers in California copied older dulcimer shapes but used guitar fretting calculators minus the non diatonic frets to fret the instruments. Appalachian and Ozark makers had always used more natural intonation (as it was easier to set by ear). This change to ET enabled chords to be played when the action was also set 'guitar style' (previously dulcimers were drone instruments played with a noter and action and string gauges were higher). The new dulcimers were quieter when played in the new style so body size/depth tended to increase (think Folk Roots company) and builders did the best they could to make the mountain dulcimer more resonant for contemporary playing on the lap by lightening the builds and using fine tone woods. Blue Lion have taken this process of fine building to great heights.

Makes sense to me. Vibration of strings transfers to bridge, transfers to top. Unless there's a sound post like in a violin, there's not going to be much transfer to the back. I'm not basing on any expertise, but it just makes sense.