Soundboard tuning and tone bars/bracing

[LuthieroftheDesertLoon]

I was watching a video today on soundboard voicing/tuning.
Where the f-holes were opened up to change the tuning of the instrument
So I'll assume this can also be done on round and oval hole mandolins soundboards.
Has anyone tried this and what were the results.

Also looking into bracing, or tone bars, left handed bracing compared to original bracing?
I just love learning about things, and like most of us want to get some feed back before building something totally off the wall.
I know the traditionalist out there, lol so don't respond to this if you can't think outside the box.
THANKS

[Marty Jacobson]

I think you should just go build your off the wall thing, then tell us how it came out! There's no real right or wrong way to do this stuff. If you try something, learn from it, and then make another one, the second one will be better. You might get lucky and have something really spectacular from the first instrument, or it might take a few builds like it did for me to get something that works well. Either way, you'll get there and have a lot of fun learning and playing along the way.
FWIW I don't think any of the stuff you mentioned is magic in and of itself, it's more about how the whole thing works together.

[buckhorn]

way outside the box.....

[peter.coombe]

When you refer to "change the tuning" you are really referring to the main air mode of the mandolin. There are many other modes of vibration. You certainly can change it by changing the size of the sound hole in an oval hole mandolin. The easiest way is to extend the fingerboard over the sound hole. That will reduce the effective area of the sound hole and lower the main air mode. I don't think left hand/right hand bracing will make any difference. There is no treble or bass side of the soundboard as far as the way it vibrates is concerned. The hole thing vibrates as a whole.

[CarlM]

Just out of curiosity, have you ever built any mandolins?

[LuthieroftheDesertLoon]

Say Marty, having a bad day buddy?.
I'm here asking questions to learn things.
Yes I like to think outside the box.
I also like to build the best box I possibly can

[LuthieroftheDesertLoon]

Hi Peter, being new to this thought, yes, changing the air mode, or chamber from what I understood of the video
from Tomy Hovington, he changed the opening in the f-hole, or size of the f-hole.
I understand the soundboard vibrating as a whole, but would disagree with the fact that the sound board does have a bass and a treble, especially when carving a top, ot how one shapes the bracing.
Feel free t correct me if I'm mis-understanding something here.
Again I came to learn more than what I know now.
and Thanks

[LuthieroftheDesertLoon]

Carl, I've built a lot of things.
The questions I'm asking is to extend the knowledge base.
I'm not here to recreate the wheel.
A lot of new tech is coming forth from people whom research and look outside the box.
No one would have ever found Montana had they not cross the mississippi

[Marty Jacobson]

Say Marty, having a bad day buddy?.
I'm here asking questions to learn things.
Yes I like to think outside the box.
I also like to build the best box I possibly can

Don't be a jerk, there's no point.

Anyway, I have a story for you.

When I was 18, I built a mandolin by the numbers, traditional, to a normal Loar-inspired plan. It came out great. I thought, shoot, if I can build an awesome mandolin from a plan, think of the awesomeness I can unleash on the world if I design one from scratch!



I built this mandolin to incorporate all the awesome ideas I had gleaned from my Internet forum research.

Some guy said his mandolin with a 14 degree neck angle sounded good. So I made this neck 16 degrees. Should be even better, right?
Some guy said his mandolin sounded good with the bridge jacked up for a higher break angle. So I made a 1.25" tall bridge with epic break angle.
I used scalloped, hole-relieved, dovetailed-notched, super-fancy carved X-bracing that I split from a billet with a froe for perfectly straight grain.
I did a nine-piece maple and cocobolo neck to make it super stable.
Handmade tailpiece with integral damping.
400 hours of inlay. I didn't have money, but I did have time (apparently).
I made a larger body, deeper body, then calculated the size of the soundhole so it would bring it back to the pitch I thought I wanted.

Strung it up.... and the top collapsed.
Also, it didn't fit in any case known to man.

The next mandolin I made, I made sure I got the basics right. I still had fun with it, it had a laser-cut soundhole in the shape of a dragon. But I made sure I knew what made a mandolin functional, and then I played around with one thing at a time.
That's basically how I try things out now. I may make a fairly traditional mandolin, or I might not even use wood to make the mandolin. But I'm going to make sure that the basic things that will make it a functional instrument are there.

[CarlM]

Carl, I've built a lot of things.

Most of the people here have built a lot of things.
For example myself, I spent over 20 years as a journeyman tool and die maker in precision electronics building injection molds and high speed carbide progressive dies while getting my degree in mechanical engineering. Since then I have worked that much again in design, building and computerized modeling for engineering stress and load analysis in several industries for major OEMs. Other people here have similar backgrounds. A lot of the luthiers here have been building 30 and 40 years and some are quite prominent. I have had to deal with apprentices with attitude many times as well as being on the receiving end from journeymen who corrected me when I was younger.

My approach to learning to build mandolins has been to try and understand what has been done. And more importantly why. I have read through about 2/3 of the 15 thousand postings on this forum as well as Siminoff's book and Graham MacDonald's book and some other resources and books on acoustics and instrument building just to get started on a sense of what is going on. I have built a couple mandolins now as well as a couple of guitars and am working on my third mandolin. I have heard prominent luthiers say you need to build at least five and probably ten to have a basic understanding of how they work and are put together. That seems reasonable from what I have seen so far. As far as the tuning plates there are dozens of threads on tap tuning on this forum. There is a range of opinions from it is the gold standard to it is nonsense and a waste of time. Look up those threads and you will get an idea of the range of opinions. There is not a separate tuning of the bass and treble sides. That is not opinion and is from vibration analysis and theory of vibrations. Peter's website has some great pictures of the modes which can help in understanding.

Marty's recommendation to dig in and try building is a good one. Building a house from the roof down is not a good idea, you don't play like Chris Thile from the first day and you will not extend the knowledge base unless you do the work of finding out what the base is. Anyone that is any good has put in a LOT of time and effort to get there.

[LuthieroftheDesertLoon]

Marty, thanks for the post. At 60 I been through all and more of what you stated.
It's why I'm here asking questions.
I'm retired so don't have a ton of money to waste on trying things.
Just like learning and looking outside the box, or expanding the box.

I'm a long time woodworker, so I'm not looking at butting a synthesizer inside a mandolin.
I've been a singer songwriter for over 31 years, of folk ,bluegrass country blues etc..
Just researching to see who has done what.
I worked at Elderly Instrument and know some great luthiers there and other places around
the US, again I like researching, and picking out things to look at think about and talk to others.
Recently have been talking to Samuel at Badwater Guitars in Michigan's U.P. about left hand bracing, so some folks think of things and others stay tried and true, but again I'll say you have to cross the Mississippi to get to Montana.
Peace

[LuthieroftheDesertLoon]

I understand what you're saying. But let's clear all this up on those that have replied.
I did not state and or say anything about coming off the workbench with a new wheel.
Did not say anything about taking shortcuts, merely asking questions from a video I watched
from Tomy on youtube who had some pretty interesting things to show and whom I think knows his way around the shop. He wasn't re-inventing the wheel either
just talking and showing how he was using the sound holes to change the tops sound
as well as his bracing techniques.
So as I stated to Marty. I'm 60 + years old, I have learned to do nothing fast, use sharp tools, measure twice and cut once some years ago.

[Stephen Perry]

There are so many avenues that have not been followed much in the mandolin world. Tuning of the current designs seems a reasonable one to keep following. What constitutes "tuning" is a universe in itself!

What mystifies me is that the arching hasn't really been investigated in the way that, for example, violin arching has been considered. I've been lucky enough to examine some rather good mandolins, and have seen one that certainly had a different arching than that we use normally.

Another aspect is the ground, a subject dear to violinistas hearts.

So much to do. How about my mandovoodoo work? Is that "tuning" or not? I am not certain, given the context of this discussion - if it's not tuning, then what?!

[peter.coombe]

I understand the soundboard vibrating as a whole, but would disagree with the fact that the sound board does have a bass and a treble, especially when carving a top, ot how one shapes the bracing.
Feel free t correct me if I'm mis-understanding something here.

I am correcting you, the physics says otherwise.

Some references
Mandolin Family Instruments, by Cohen and Rossing, in The Science of String Instruments, edited by T D Rossing, Published 2010 by Springer.
http://petercoombe.com/jaamim7.html
http://petercoombe.com/jaamim8.html

Another good source of information are the books by Australian luthiers Trevor Gore and Gerard Gilet, but they are guitar oriented. However, Cohen and Rossing have shown that a mandolin vibrates like a guitar, so the information in the books is relevant.

[CarlM]

What mystifies me is that the arching hasn't really been investigated in the way that, for example, violin arching has been considered.

I am not certain but I suspect that with the greater forces on a mandolin top there is not as much latitude to change arching and neck angle without collapsing the instrument. That is just speculation though and would be interesting to investigate.

[Br1ck]

To the casual glance, my Silverangel is a pretty run of the mill A style f hole mandolin. However the top and back are arched significantly greater than "normal." So much so that it won't fit most cases. It is X braced and has a redwood top. Not so out of the box, but maybe 1 out of 1000 mandolins fit this description. These design features make this a somewhat unique instrument significantly different from others. Many won't like it. Many will.

I played a bunch of vintage guitars today. Know what? I don't like Brazilian rosewood D 28s. At least none I've ever played ( 6 or 8).If I were building I'd never shoot for that unless I was trying to earn a living. LOL.

Follow a tried and true blueprint and your chance of success is greater than if you don't, provided what you want is what everyone else wants. A builder I admire is Steve Sorenson. There is someone willing to try something new, but that is based on a ton of experience and incremental advances to guide him on his quest.

Any new bracing pattern a neophyte might try might work out of pure luck, so try what you want.

[rcc56]

I don't build instruments. I play them and repair them. I've been up to my elbows in dozens of old Martin and Gibson guitars. I've had the backs off a few mandolins and guitars, and rebuilt a handful of them. Tried to control the sound of violins with soundpost placement and by recarving bridges and adjusting their height and thickness. I've weighed dozens of instruments to try to find a correlation between weight, tone, and response; and found that weight was not necessarily as influential as one might expect it to be. I've read books and articles by experts, amateurs, and quacks. I've tried to figure out why 3 instruments that were all built to the same footprint sounded completely different from each other.

It's an art, not a science. I don't believe that we have necessarily completed the exploration of how arching, thicknessing, and bracing a carved mandolin affects tone and projection. This is because carved mandolins have only been hand-built in large numbers for a couple of decades.

We know from Hill's history of Stradivari that Strad routinely varied the size, shape, and graduation of his instruments, and the placement of his f-holes. We also know that he discarded partially completed plates that did not meet his standards. While we might not know for certain what his particular principles were for evaluating the best way to handle a particular piece of wood, I think we can surmise that he was guided by the characteristics of the individual piece of wood itself-- its weight, stiffness, and sound when tapped.

Experimentation is as important to the development of good instruments as tradition is. We should encourage it. Maybe the old Gibson designs will prove to be the best, or maybe we will find something better.

Lyon & Healy made some great carved mandolins. Also John D'Angelico. Upon encountering an unusually impressive 2 point oval hole D'Angelico in George Gruhn's shop, I asked if they had looked inside it to see what made it tick. George replied, "No, but let's look at it now," called his lead repairman, and we stuck a light and a mirror in it. We found a single transverse brace, set farther back from the sound hole than a Gibson or L & H brace. How Mr. D'Angelico came up with that brace placement we do not know, but it worked; and I think we can be reasonably sure that he did not locate it there randomly. I wish we had taken some measurements of the instrument.

Anyway, let's try to keep our minds open.

[Tom Haywood]

Has anyone tried this and what were the results.

I've been reading the Cafe Builder's Forum almost daily for about a decade now - not as long as several posters in this thread. One thing I've learned is that if you can think of it, somebody has already tried it and posted about it somewhere on the Cafe. Another thing I've learned is that some of the members feel like you should search the Cafe for previous answers before asking your questions. Others will just post links to previous threads. And others will engage in your conversation because, well, there really are no answers set in stone. Searching the Cafe can be frustrating until you learn to start with a Google search of this site. Anyway, I get it that money is tight, but any mandolin you design or any modification you try to a previous design runs the risk of serious failure. More likely, however, you'll discover that the difference it makes is not much. If it makes sense, you just have to try it and see what happens, because your experience will be different from someone else's. Then, post your results here, because we all are interested.

[LuthieroftheDesertLoon]

Tom thanks for your post. I totally get what you're saying.
Again I'll say it again, I'm not looking at reinventing the wheel here.
I'm a pretty hard core wood guy, to the point that wood bindings and not plastic
or plastic anything.
So with that being said if folks haven't watched Tomy Hovington's video (https://youtu.be/c0OVTwLyU9o) on
Voicing of the Octave Mandolin, this is what I'm asking (Only) if anyone has worked with this
along with styles of bracing.
Again I'm talking with another luthier about left hand bracing, I know nothing about
and Samuel states not many like the idea, but, he is still playing with it
So these are "Just" Questions I've not started a billzion dollar company to flood the market.
I like the fact that if I can use a 432 hz to achieve my sound board then I want to research that.
If it doesn't work, then I'm not going to use it.

[LuthieroftheDesertLoon]

Sorry, posted the wrong link
Tomy Hovington Voice tuning the Mandola

https://youtu.be/qflcCRI4LDQ

[sunburst]

I told myself that I would not get involved in this thread, having been admonished not to if I can't "think outside the box" (which, to me, roughly translates as "reinvent the wheel").
I've been a luthier, part time amateur for a while and then professional for that past 30 years. I've thought about bracing patterns and their variations, I've tried alternate bracing patterns (though thy have all been inside the box... some have tried them on the outside), I've pondered alternate designs and construction, alternate uses of materials, many of the ideas that get tossed about by curious luthiers who are still becoming educated.
Here are the two main conclusions that I've reached, some of which has been touched upon by others here.

- Instruments have been made for centuries. In the course of that time they have more or less become "reverse engineered". If you can think of a potential innovation, someone, somewhere, at some time has almost certainly thought of it in the past. Most things have been tried, and things that didn't work tend to get left behind and things that work tend to remain in instrument designs. That's how instruments have gotten to be what they are. They are an accumulation of things that worked and it is not easy to improve them other than improving the details of those things that worked. (Sorry, that is not much in the way of "out of the box" thinking, but that's the way it is.)

-We now have experimental evidence of what goes on in instruments. We have scientific papers (which can, admittedly, be difficult to read for those of us without the background in science that it takes to understand the language) that explain what happens in an instrument when it is set in motion by playing or otherwise. That information was very eye-opening for me. It made me realize that many of the "outside the box" ideas that I had were not worth pursuing because they were not likely to affect the normal modes of motion in the instrument. I short, by learning more and more about instruments, how they are made, what they do and how they do it, I've narrowed my perspective on what thought lines are most likely to be worthwhile. In other words, the more I learn the more that knowledge directs my thinking into the existing box rather than out of it.

Peter listed some very good references in his post. There are also many earlier papers on guitars, and as Peter said, they behave very similarly to mandolins.
As fun as it seems to be for a lot of people, we no longer have to speculate and discus hypotheses of what might improve the function of instruments from an uneducated perspective. The information is out there for the taking.

[LuthieroftheDesertLoon]

Johm: Again the ONLY Q. Is has anyone first Watched this video.
2. AGAIN, i'm inside the box, basically playing with the air chamber (If you watch the video), with everyone watching the Video, you'll then understand (Maybe) the questions I'm asking.
AGAIN I'm not creating the wheel, I'm working with what has been tried, and extending the
possibilities of what might be.
In 1923 Loyd Loar didn't have the programs available to him that we have now, in measuring hz on a soundboard through a computer.
No more than someone had a pneumatic hammer to do metal work in the early 1900's, or a air nailer to frame houses.
So with that said, whats being utilized today.
Sometimes the light bulb goes off and a new idea comes forth.
Sometimes it's just an Ole well moment.
To think one dimensional would never had gotten us past the caveman days.
Someone brought forth fire.

[sunburst]

OK, the video.
In my early mandolins, I was using Roger Siminoff's book as a guide (much like the majority of builders these days). Like many others, I labored and agonized over the whole plate tuning and "air chamber" tuning section. I struggled to tune tone bars to specific notes, I shaved the edges of f-holes striving for that "perfect" note, I wrote down notes of what I did and what the results were, and gradually built a number of mandolins to have mental sound files to compare. I found absolutely no correlation between the notes to which parts of the instrument were tuned and the sound of the instrument.
The main air resonance, (the Helmholtz resonance) is determined by the size of the enclosure and the size of the aperture (F-holes, in this case). Changing the size of the box is not practical once the instrument is built, and that leaves the size of the aperture as the only means of adjustment or tuning of the resonance. The thing is, there is a mathematical relationship at work there that makes it so that it takes a very large difference in the aperture to make a small change in the Helmholtz. (I don't know the exact progression, I feel no need to know that, I just know that it takes a big aperture change for a small Helmholtz change, and that's enough for me.)
Eventually, I quit trying to tune parts to specific notes, but I continued to write down what the notes were. Sill, no correlation to the sound of the instruments. I ultimately abandoned any sort of tap tuning as an unnecessary procedure and a waste of my time.
Upon further thought, what is so important about the specific notes of the modern tempered scale? The frequencies are pretty much arbitrarily chosen, they have changed from time to time and place to place. Why is Eb any better than any other frequency for a resonance? As I see it, it is no better.

Now back to some of those papers linked by Peter. Yes, they are pertinent to this discussion, that's why I mentioned them (and I assume why Peter mentioned them). If you read Peter's work you will find that he has a large database of tuning of mandolin parts and he has been able to track them through the build process and show results. He is able to do that because of his large sample size and large data base from which to work. As I see it, that is the only method of using plate tuning and so forth to our advantage. Without a large database (preferably from our own work) plate tuning and air tuning are of no use to us.
If you read Rossing's and Cohen's work you will find that coupling is a very important concept is successful instrument design. To simplify that to it's (somewhat inaccurate because of simplification) basics, that means the parts of the mandolin work well together because their frequencies are such that they reinforce one another and broaden peaks in the sound spectrum. In other words, particularly the top, back and air volume will resonate at frequencies that are close but not the same. There is a range of frequencies for each of those; top, back, and air; that will work. They don't need to be tuned to specific notes nor to specific intervals to couple, they just need to each be within a good frequency range to couple.
In light of that, tap tuning, as it is normally understood, is of no use to me. Yes, I listen to my wood, rub it, tap it, feel the stiffness and weight. I feel like those are ways to evaluate a piece of wood to help direct me when carving, but I absolutely believe that tuning to specific notes of the modern tempered scale is of no use.

[Jeff Mando]

........ or a air nailer to frame houses.

call me old fashioned, but everytime I see someone using an air nailer, I think "that lazy SOB!"
(son of a biscuit-eater, just to be clear)

[LuthieroftheDesertLoon]

When your building houses for a living, come on, it has it's place