What is a mandolin?

[billhay4]

I am thinking of trying an exercise in mandolin design based on totally non-traditional and non-aesthetic considerations.
To begin this, I have come up with the following elements that make up a mandolin:
Scale length
a. Any to produce the proper sound (see Sound below)
2. Body size
a. Any
3. Tuning
a. GDAE
4. Number of strings
a. 4 pairs of 2
5. Fretted fingerboard
6. Sound
a. Middle C on fifth fret of G string
b. Other notes in scale with this
c. No other considerations such as sustain, chop, etc. need be pre-defined
7. Body
a. Any shape is okay
b. Structurally sound
c. Hollow
d. Soundholes
e. Some form of top bracing is necessary, but what kind is not predefined
8. Neck
a. Solid
b. Can meet body at any fret
c. Any join with body is okay
d. Fingerboard can be elevated or not
9. Wood
a. Any to produce best sound
b. Other materials (carbon fiber, etc.) are acceptable
10. How played
a. Strummed or plucked with plectrum
b. This assumes metal strings
I am aware there are instruments that violate some of these conditions and that there may be other conditions I have not thought of.
I would appreciate any input you might have on these so I can refine my thinking.
Once I have a working definition, I will work on design elements that satisfy these conditions, and no others.
Thanks for indulging a whimsical old man.
Bill

[markishandsome]

I would absorb the bracing requirement into the "structurally sound" category. This might free you up to consider other possible ways of constructing the soundboard than braces.

Also maybe "sound holes" could be generalized. A banjo-mandolin would not meet this requirement, for example. Maybe somthing like "must be able to produce sounds audible to the human ear without need of electric amplification".

[dave17120]

Do you want to specify WHICH octave for the GDAE??? Dave

[dave17120]

Also, does it have to be fretted?? Or is that a way of differentiating it from a violin? Dave again.

[Bernie Daniel]

Dave 17120:Do you want to specify WHICH octave for the GDAE???

Yes I would think you would want to do that other wise the defination could also apply to an octave-mandolin. #Also I would re-name catagory 6. "Sound" as "Pitch".

Under catagory 7. Body. #-- All mandolins are not hollow -- there are electric, solid body mandolins available including those by Gibson and Fender etc #No sure if that is something you want to consider.

When you get your list filled out it would be interesting to see if you could use it to write a narrative defination of a mandolin. #Having written that it occurs to me that someone has probably already done that.

[DryBones]

It's a black hole of the music world that will suck in all your time, money and attention. No one can escape it's pull once exposed to it. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

[Bill Snyder]

Do you want to specify WHICH octave for the GDAE??? #Dave
He did.
6. a. Middle C on fifth fret of G string

[PseudoCelt]

There was a discussion similar to this almost exactly a month ago:

What makes it a mandolin? Not a simple question! (http://www.mandolincafe.net/cgi-bin/ikonboard.cgi?act=ST;f=12;t=42963;hl=mandoline)

Patrick

[Jerry Haynes]

According to Webster....
Mandolin- a dreaded disease that totaly consumes ones self and for which, thank God, there is no cure.

don't believe me http://www.mandolincafe.net/iB_html/non-cgi/emoticons/rock.gif? look it up Jerry http://www.mandolincafe.net/iB_html/non-cgi/emoticons/laugh.gif

[thistle3585]

Anyone know if there was any specific criteria for the Rice architectural students when they did their mandolin project?

[billhay4]

Thanks for the thoughtful replies.
I specified hollow bodies arbitrarily because it limits the sound production to a resonating inner cavity driven by strings vibrating across the top. I think I was subconsciously deferring to tradition here. The same thing could be said of the four pairs of two strings specification.
Some hidden assumptions are inevitable, I suppose.
As to the black hole characteristics of this endeavor, I am aware of that but the idea of trying to design an instrument from scratch appeals to me. Wish I had the intellectual tools to do it, but life is full of futile gestures.
Bill
PS> I don't know what the specifications the Rice students had to follow were, but I read some of their posters and was struck by the varying criteria they used to come up with their designs. It also struck me how little they used musical considerations. Finally, they seemed very tradition conscious, too.

[PseudoCelt]

I think I was subconsciously deferring to tradition here.
I think your original question subconciously deferred to tradition by asking "What is a mandolin?". All other posts also deferred to tradition, or at least design precedents, by trying to say what attributes make a mandolin what it is.

If you want to truly design an instrument from scratch, perhaps the best way would be to determine the design characteristics that best allow a specified person to play a specified musical style (or styles) using a specific playing style (or styles). If it turns out to be something close to a mandolin, then it's a mandolin.

It's an interesting question, but one which will possibly not give a definitive answer. In the other thread on this topic that I posted a link to earlier, I think I suggested a relatively simple definition of a mandolin, that could be used a reference point or baseline, by which the relative "mandolin-ness" of other instruments could be judged. This avoids a long and wordy catch-all definition.

Patrick

[billhay4]

I agree that defining the issue in terms of "mandolin" does defer to tradition and makes all kinds of assumptions. This entire process is arbitrary if you look at it closely and that is one of the arbitrary elements of my "quest". There are many others.
However, I am a mandolin dilletante, not a music dilletante, so I have chosen those terms. My interest is in what a mandolin would look like in the absence of tradition. It assumes it would exist at all, of course. It is also an arbitrary endeavor, perhaps even futile.
I am going to refine the elements I have listed above and will post them again when I do so. In the meantime, I'd still love input on them.
Bill

[markishandsome]

My interest is in what a mandolin would look like in the absence of tradition.

Well if that's what you want I might humbly suggest that you're looking for it in sort of a backwards fashion. Cooking up the broadest possible definition of mandolins will never give you a single answer. Clearly a lot of different looking and sounding instruments are mandolins. Take a look at the "Mandolin oddities" thread and you will see dozens of mandolins that defy tradition, and more that stem from other traditions than where Orville was coming from.

If you were the first person to think of making a mandolin, you'd almost certainly end up with something with a scale length of about 14" give or take a few inches. No one would invent an instrument they couldn't play because the frets were too close together, or too long for any wire strings to tune up to pitch without snapping. If you the inventor had a knowledge of acoustics you would build the air chamber to be such that the volume of air inside resonated at a frequency that coupled well to those of the strings. Soundhole size follows from similar considerations and you end up with something almost exactly the same size as trad mandos.

Body shape is totally up for grabs, there's no reason to make it any particular shape that doesn't put your eyes out. But if you had never seen a musical instrument before, you'd probably think up something pretty simple and easy to construct. This starts looking like either a flatiron pancake or the Savart trapezoidal fiddle, assuming you're using wood and not clay pots or gourds or something.

Which wood you would use would probably be determined by what you had around you. In the absence of any luthiery traditions, would you choose maple and spruce? Probably not a first. You'd end up making a bunch to test out different materials (another reason to go with a simple body design) and picked which combination you liked best.

If you just up and invented the mandolin out of thin air, there's no telling what you'd get. But if you let it evolve, you'd probably end up with something resembling a traditional mandolin. Maybe not the north american traditional mandolin, but SOME tradition of mandolin.

[Will Kimble]

I have thought about this some, my opinion is that it has to have 4 courses tuned to EADG to be a mandolin. #After that, things are pretty flexible depending upon what you are trying to achieve. #But to quote the advice I received from one of my favorite builders back when I was experimenting wildly, "What is it about a Loar that you don't like that you think needs to be changed?" #http://www.mandolincafe.net/iB_html/non-cgi/emoticons/rock.gif

Will Kimble

[sunburst]

A little input from me:

I'd use wood for most of it. Wood is easy to get, relatively easy to work with, and that's what I'm used to working with. With that in mind, I'd keep the properties of wood in mind as I designed the shape, keeping to sound wood working principles as much as possible, ie minimal cross-grain glue joints, grain orientation done to take advantage of the strength and stability lengthwise the grain while making allowances for the flexibility and movement crosswise the grain, and etc.

I would also strongly consider ergonomics in the shape of the body. I'd probably start with a styrofoam model and carve it until it feels comfortable to hold, with no particular regard to practicality as an instrument shape. From there, I'd try to figure out how to keep many of the elements of my ergonomic design while modifying the shape into a strong structure capable of supporting the tension of 8 steel strings, make it practical to build from wood, and make it playable.

[billhay4]

Now we're cooking.
I did not intend to propose designing a mandolin from the perspective of the first mandolin builder. I agree that, if one did so, the result would resemble the evolution of the instruments.
What I intended to propose is designing an instrument in the absence of bowing to tradition, but with all due consideration to what we know about the technical aspects of producing music.
So, John proposes ergonomic considerations. Great idea; I hadn't considered this. This would, I think, introduce some limitations on size, perhaps the inclusion of an armrest, limitations on scale length and fingerboard width, a limited body thickness and width, etc.
As for shape being up in the air, I would wonder if various shapes affect sound. Does the sound chamber produce clearer tones if it's symmetrical, rounded, larger, etc? Anyone got any input on that?
Finally, I agree with Will that it need four course tuned EADG to be called a mandolin. I will adopt that criteria for sure.
Thanks for intersting ideas.
Bill

[sunburst]

The shape of the 'air chamber' certainly does affect the sound, but speculating as to how is pretty close to pointless.

A violin shape, or a smaller guitar shape, tends to separate the air modes into two sections, at least to some extent, so a small 'waist' can make a difference in the sound, but even that measurable difference is not apparent to the untrained ear. I wouldn't waste much time speculating how the shape might affect the sound. That's for subsequent instruments for the next few hundred years. This is the prototype we're talkin' about.

[buddyellis]

Shape and a few other variables (fingerboard/fretted or non-fretted, strings, for instance) can make a serious impact on the tone of the instrument. For instance a violin, plucked with a plectrum, sounds amazingly like an old time banjo, to me. I think it's the combination between the lower tension strings, and the lack of frets that makes most of that, though. Choice of strings, though, is probably in the top two or three things, IMO, in determining tone.

String tension, to some extent, drives your plate design, too.

[Dave Cohen]

John, where did you get that stuff about "separating the air modes into two sections"? The violin has a regular Helmholtz resonance, a regular longitudinal sloshing air mode, and a regular sideways sloshing air mode, just as do mandolins and guitars. The difference is that the elongation of the violin body causes the sideways sloshing mode to occur at a considerably higher frequency than the longitudinal sloshing mode. Just as with f-hole type mandolins, the longitudinal sloshing mode has its' node in the middle of the soundholes, results in little or no net movement of air in or out of the soundholes, and so does not radiate strongly (if at all). Similarly, the sideways sloshing mode in both mandolins and violins should result in radiation with a dipole component, weaker than the monopole radiation of the Helmholtz mode. So most of what instrument makers have to work with is the Helmholtz resonance and the main body ("trampoline" or (0,0)) modes.

[billhay4]

So, Dave,
how would you translate what you have just related into an ideal shape for a mandolin?
Thanks,
Bill

[sunburst]

John, where did you get that stuff about "separating the air modes into two sections"?
I'm pretty sure I read it somewhere, and I thought there were graphic representations of the air modes in whatever paper I though it was in. It's possible I was reading some bogus information (there is some of that about, after all) that I assumed was mostly correct. I was under the impression that the 'sideways sloshing' modes had two resonances because of the waist and the two different size bouts.

[billhay4]

Based on ergonomic considerations only, I would suggest the following rough sketch for a mando. The upper cutout is so you can access the upper strings. The cutout on the opposite side of the instrument (which is too dramatic on this drawing) is for a beveled edge to soften the place where the arm rests on the instrument.
Any reactions?
Bill

[Chris Baird]

Defining anything is actually quite difficult. I will illustrate. It ultimately leads to some absurdly philosophical holes.

I can tune my mandolin to anything I want. In fact there are alternative tunings for mandolins. There goes the eadg thing.

I can take off 4 strings and it is still a mandolin. There goes the courses thing.

I can actually take all my strings off, my tailpiece, my tuners, etc. It could be completely stringless and unplayable but still be a mandolin.

To REALLY distill something down to its lowest most undividable status is rather difficult.

But, I somehow think that this isn't the answer you were asking for and to go on would be fruitless.

[Dave Cohen]

John, each of the "sloshing" modes is a single resonance with a single eigenfrequency. Same goes for higher modes, and body modes, and string modes too.

The simplest analogy is a string. The fundamental or first harmonic motion of a string is the half wavelength motion from nut to saddle. The second harmonic is the whole wavelength motion, with a node approximately over the 12th fret, at twice the frequency of the first harmonic. The fact that it has a node separating two vibrating segments vibrating in antiphase doesn't make it two resonances. It is still one resonance, with one eigenfrequency, and it is still one normal mode. Same thing goes for body or wood modes, and air modes too. The longitudinal sloshing air mode, with a node approximately under the bridge, is one resonance, with one eigenfrequency.

Bill, I don't think that there is an "ideal" shape based on plate mode shapes or air mode shapes. Consider the thread on the Rice University mandolin designs. Could the kidney-bean shaped mandolin be a killer instrument? In the hands of a luthier dedicated to making it work, absolutely yes! As far as air modes go, the kidney bean shaped mandolin will have a kidney bean shaped Helmholtz resonance. The Helmholtz resonance is the movement of the mass of air in the soundhole(s) being pushed by the "spring" of the volume of air in the body cavity. That spring of air is a 3D spring shaped exactly like the inside of the body cavity - a kidney bean shaped spring, if you will. Can it be made to have the "right" frequency, whatever that is? Soitinly! You might or might not be surprised to know that violins and f-hole mandolins have their Helmholtz resonances at about the same frequency, ca 280 Hz. So you can make the mandolin any shape you want. Go ahead and make one shaped like a watermelon, or like a cheesebox with a lizard crawling out of the side. Uh, wait a minute, someone I know already did those.

[Eugene]

I have thought about this some, my opinion is that it has to have 4 courses tuned to EADG to be a mandolin. #After that, things are pretty flexible depending upon what you are trying to achieve.
The obvious implication is that if one retunes the e" strings to d", s/he has invented a new instrument. Also, there have been several instruments legitimately named mandolin with more courses and/or different tunings. As Patrick offered, click here (http://www.mandolincafe.net/cgi-bin/ikonboard.cgi?act=ST;f=12;t=42963). Also, click here (http://www.mandolincafe.com/archives/builders/early.html).

[Will Kimble]

Take 4 strings off and you have a domra. #To me, a defining part of what makes it a mandolin is the sound of the unison pairs.

Sure there are mandolin pieces in altered tunings. #And there are early forms of the mandolin that used different tunings from what is standard now. #But to me, the fact that it is tuned in fifths at the same pitches as a violin is a defining characteristic of the mandolin. #I might change it to play "Get Up John" but I am not gonna play in that tuning all night.

There are a lot of design implications to just these two points - fingerboard & bridge dimensions, range of string tensions with available string sets, appropriate scale length, optimum body size for this range of pitches, optimum aperture size, bracing patterns, etc. #Then all of the ergonomic considerations. #

Will Kimble

[Eugene]

However, the first things to be called mandolin were tuned wholly or mostly in fourths. #In deference to precedent, those are mandolins. #There are still modern-design, 6-course instruments built for a standard tuning of mostly fourths to be named something like "mandolin" and to emulate the functionality of the first mandolins. #They're mandolins too. #There were 4-string mandolins tuned in fifths (e.g., Cremonese and Bresciano) before Ukrainian domras existed. #Those are mandolins. #An instrument is named whatever its contemporaries, especially its players and makers, are calling it whether I like it or not. #Revisionist renaming for modern convenience is a bad business. #If the context requires clarification, feel free to add adjectives to describe whatever mandolin type is at hand.

[Dave Cohen]

When I first brought f-hole and oval hole mandolins to Rossing's lab in 1999, he thought of them as little guitars. After we did the modal analysis on the two instruments, he was impressed that the oval hole instrument and the f-hole instrument seemed to be "two completely different instruments". Well, maybe not that different, but different enough. Compared to, say, flat top guitars, mandolins are extremely diverse. Even if you factor in archtop guitars, the different types of mandolins look more diverse by comparison. In guitars, the constructional details and the body mode and string mode frequencies are surprisingly similar throughout. The differences in body mode and air mode frequencies between, say, an archtop oval hole mandolin and an archtop f-hole mandolin are large by comparison. That kinda leads me to agree with Eugene on the "what is a mandolin?" question. Mandolin family instruments are currently a very diverse collection of instruments; so diverse in fact that the use of adjectives to differentiate the different types of mandolins has already become common practice. Just look at all the different threads in this forum for corroboration of that.

[billhay4]

Thanks for the enlightening reply, Dave.
Based on the concept that there is no "ideal" shape for a mandolin based on sound, I would venture that other considerations must come into play. Two of these would be ergonomics and structural soundness.
I have suggested some ergonomic considerations in my poor drawing above. Anyone have any others?
As for structure, I think we must go with a generally rounded shape. I had thought of a diamond shape (to accomplish the two ergonomic concerns expressed above--access to the upper frets and comfort for the right arm) but the short grain at the side point bothers me. A rounded shape should alleviate this, but that shape would be interrupted to accomplish the two ergonomic regions as I have tried to show in the drawing.
The one on the right would have to be a separate rim piece I think. The other could be done like it is done in guitars with a feathered edge where the arm rests. You could also use a separate arm rest as are available now. Or you could have a symmetrical indent using a separate curved rim piece.
Question: do the internal blocks needed for the changes in rim curvature affect the sound negatively?
Enough for now.
Bill

[pelone]

To, perhaps further muddy the water, or clear the air, a couple of things follow. I have built three mandos that have circular tops and backs--I obtained the rough diameter and depth by pouring rice crispies into an F then measured the volume of the removed cereal. I later used a plenometer and measured the F and came out very nearly the same. The volume question/consideration is interesting as I did not want to wander too far for fear of loosing the "mando" quality and resonance characteristics. My inpiration was a pot shaped mando that I restored that was made in Kansas City in the 30's.

All three instruments sound like a mando, even though one is strung with four strings rather than eight. My question is self serving. Do mandos crafted by those of us who diverge from the norm still qualify as mandos? Or are they snickered at for their oddity? I have never taken the instruments to a bluegrass jam for fear of ridicule but remain a closet picker instead.

[markishandsome]

I think the reason it's still a mandolin even if you take all the hardware off is because when it was designed, built, and named, it was intended to be used with strings and hardware etc. You can retune a mandolin, but only a few steps before things stop working as envisioned by the original builder. Loar mandolins didn't stop being mandolins when concert pitch was upped to A440. "GDAE or thereabouts" is probably agreeable to most, at least as a starting point. We can move up to sixteen course whathaveyous once we get all the bugs tinkered out of the prototype. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif

[Bill Snyder]

Loar mandolins didn't stop being mandolins when concert pitch was upped to A440.
Forgive my ignorance but your statement leaves me a bit curious. What was a concert A prior to the change and when did this change take place and who decided on the change?

[MikeB]

Finally, something (http://www.uk-piano.org/history/pitch.html) I can add to this conversation... http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif

[JeffD]

Wow, philosophy.

Remember to qualify as a mandolin, said musical instrument must be regularly confused with a ukelele. I don't know why either.

[Antlurz]

Or as one of the Dillards said, "It's got to be as hard to get in tune as a set of bedsprings" http://www.mandolincafe.net/iB_html/non-cgi/emoticons/laugh.gif

Ron

[Bill Snyder]

Or as one of the Dillards said, "It's got to be as hard to get in tune as a set of bedsprings" http://www.mandolincafe.net/iB_html/non-cgi/emoticons/laugh.gif

Ron
They cinches it. It has to have unison courses. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

[jbrwky]

That's a fun site. They have this electronic tuning fork. Tuning Fork (http://www.onlinetuningfork.com/)

[Eugene]

"GDAE or thereabouts" is probably agreeable to most, at least as a starting point. #We can move up to sixteen course whathaveyous once we get all the bugs tinkered out of the prototype.
It depends on the type of instruemt named "mandolin"; [g]-[b]-e'-a'-d"-g" was "mandolin" before g-d'-a'-e" was. However, while the earlier form and instruments built to emulate it are legitimately named "mandolin", they are obviously a distinct type from the more recent Neapolitan and Roman and even more recent archtop types. Six courses in fourths as standard "mandolin" came comfortably before four courses in fifths--then there was the 8-course mandolone of the late 1700s of obvious derivation from Neapolitan types, lute-like 7-course mandora/bass mandola a la Presbler and Radice, etc.--so we've really moved down to four from six and more.

[Eugene]

Finally, something (http://www.uk-piano.org/history/pitch.html) I can add to this conversation... http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif
Hey thanks, I enjoyed that little article.

[MikeB]

Well, you're welcome, of course, Eugene. I assumed you might have written that article http://www.mandolincafe.net/iB_html/non-cgi/emoticons/wink.gif !

This interesting discussion seems to be winding down a bit. I wonder if Bill got the answer he was looking for? Funny, how a question "what is a mandolin?" can generate a couple of pages and several days' discussion on a website dedicated exclusively to things and matters about mandolins.

Maybe there was a different question underlying Bill's OP. Like, "How far can I stretch the design of an instrument and still call it (or have it recognized as) a mandolin?" Or maybe, "What elements of an instrument I want to design are necessary to be able to call it (and have it recognized as) a mandolin?"

Those might not help, either. I'm just trying to steer more towards the concrete and less towards the abstract.

What about it, Bill? Have you changed any of your original parameters? What does your list look like now? More to the point, have you gotten any further with your project? http://www.mandolincafe.net/iB_html/non-cgi/emoticons/rock.gif

[Bill Snyder]

I say design it, build it and then ask us what to call it. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/laugh.gif

What is a bit interesting or perhaps sad to me is that while looking for information on Howe Orme mandolins I found some sites that said that they were NOT correctly called mandolins but they were more accurately called mandolinettos. It is my understanding that when they were being marketed by Howe Orme the name mandolinetto was never used. This term got used for them after the venerable F5 gained in popularity decades later.

[Tebbie bear]

If you are talking egronomic then you really should look at a fender stratocaster. maybe a mini stat made an inch thicker and hollowed out would be about right.

[billhay4]

I'd like to reiterate two questions I posed above:
1) Do internal blocks affect the sound of an instrument? Would a perfectly smooth interior be ideal?
2) Are there other ergonomic requirements besides access to the upper frets and a comfortable place to rest the right arm?
I am focusing on the body here. Will pose some questions about the neck later.
Thanks,
Bill

[Patrick Killeen]

2) Are there other ergonomic requirements besides access to the upper frets and a comfortable place to rest the right arm?
One ergonomic consideration for the other end is that the headstock is important as a place to put your thumb when using the lower frets. I know this from playing my headless emando.

Having somewhere to put your left thumb behind the finger board might also turn out to be an issue if the upper frets extend over the body.

Regards

Patrick

[markishandsome]

1) Everything effects the sound of an instrument. Whether those effects are perceptible or good/bad is a matter of opinion. I don't think the effect of the blocks on the air chamber is at all important. Where they contact and stiffen the top is a bigger deal, but still, there is no "ideal" in the absence of tradition. If you built the first mandolin, it'd be the best sounding mandolin ever made. If you could cook up a way to keep the thing from falling apart without using blocks, I'd take my hat off to you. Check out the thread on varnishing mando interiors for somewhat relevant discussion. Braces/tonebars are the same story.

2) If it's meant to be played sitting down, you might consider the lap-contact area ergonimics. The neck attachment angle could be an ergo-factor? Finger-rests? A way to keep the strings behind the bridge from chafing your wrist? Maybe a way to keep the back off away from the player without need for a tonegard? Different pickers with different styles hold their instruments differently. It'd be hard to find a design that would be optimally comfortable for everyone.

[billhay4]

Thanks, markishandsome,
Excellent suggestions.
As for blocks, an A instrument certainly minimizes interior blocks, as would any roundish shape as opposed to one with points. I am also thinking of solid "kerfing" as opposed to kerfed kerfing.
As for braces, I saw one instrument with braces on the outside which I found fascinating. Not sure it's practical, though. I will think on it.
I also had wondered on the back contacting the stomach (especially mine!) issue, but have not come up with any ideas yet. There are double top instruments and I suppose a double back is possible, but weight is a big issue there and I'm not sure the double back would actually improve sound.
As for anyone interested in reading up on design, you might look at David Pye's The Nature and Aesthetics of Design. Interesting read even if it's a bit dense in places.
Thanks,
Bill

[Bill Snyder]

Kerfing is a verb. You use kerfed lining or solid lining.

[billhay4]

I stand correctable.
Bill

[Bill Snyder]

I apologize for the correction - just feeling a bit curmudgeonly. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/tounge.gif

[billhay4]

Actually, I appreciate the correction. I have a tendency to be fast and loose with the language and it's good to be reined in every once in a while.
I was just making fun of being made fun of.
Bill

[markishandsome]

Bill, you should really read some of the info on this forum about acoustics and air chamber resonances before you baselessly decide that a "perfectly smooth" interior is "ideal". That's just hooey. Blocks and linings are important structural elements and should not be comprimised for some half-baked notions about what's best. Breaking from tradition doesn't mean you have to ignore hundreds of years of scientific research on the subject. Solid linings are the norm on violins because of tradition. Everyone else uses kerfed linins because they're easier to bend and provide a wider rim of support, especially for instruments with binding.

I always thought the Rigels with the radiused sides were pretty ergonomic.

[Bill Snyder]

I always thought the Rigels with the radiused sides were pretty ergonomic.
And with the Rigels there wasn't any kerfed (or solid) linings needed. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

[billhay4]

markishandsome,
I haven't decided anything. I have merely speculated that a smooth interior might allow the air mass in there to vibrate with the least "interference".
Further, I have no intention of designing something that is structurally unsound. However there are many ways of acheiving this. Solid linings are, in fact, linings. Where is the loss of structural integrity in that? Braces can be put on the outside of an instrument as can blocks (I spent part of last night envisioning a new neck joint using a partially external block).
I am not aware of "hundreds of years of research", but I am an amateur and not a scientist. I have been reading some of the literature, but have much more to go.
However, as you seem to be an expert, why don't you contribute to the conversation I have started constructively, instead of taking delight in my ignorance? What is the best shape for the inside of an instrument? Why is lining and blocks better than a smooth interior? Why use kerfed linings when you can use solid willow linings and bend them easily with modern bending methods?
What about all the other questions I have posed? Constructive input is more than welcome.
I am not an anti-traditionalist; I am however trying to isolate design elements that produce music, a structurally strong instrument, and comfort for the player. Other elements I wish to leave out of the equation for this admittedly quixotic exercise.
Finally, I would ask what harm does one dilletante coming up with a "bad" (read non-traditional) design do? Seems like a small exercise in futility to me, not something to get exercised over.
Thanks,
Bill

[markishandsome]

Sorry, rough morning. I feel like I've been mostly constructive on this thread. Quote from you from page 2


Thanks, markishandsome,
Excellent suggestions.

Felix Savart was one of the first physicists that I'm aware of to study musical acoustics back in the 1800s. There are other people on this board who know more about the history than I. Acoustics is all just classical mechanics, which has been studied for thousands of years.

I'll go out on a limb here and say (again) that there is NO "best" shape for any musical instrument. What would that even mean? Everyone has different ideas about what sounds good and what feels comfortable. Even structural integrity doesn't point one to any particular design. There are lots of ways to build mandolins that all work about as well in this regard.

I'll quote John Hamlett from the finishing thread I mentioned:


Sound doesn't "Bounce around" inside instruments. Sound doesn't go into little pores and get lost, not being able to find it's way out.

I would educatedly guess that sound waves are not "interfered" with by anything inside the box. Uninformed speculation about how things work is the only exercise in futility here. Taking the mandolin back to the drawing board is far from pointless. It's why Orville Gibson's name is still remembered and probably the only reason any of us are talking mandolins in 2007. I don't think you'll be able to a priori deduce what the best possible mandolin could be without building dozens (hundreds?) of experimental models to determine scientifically what works and what doesn't.

As far as keeping the instrument off the belly, how about something like what this bowlback is sporting, but on the other side:

[kestrel]

First, a disclaimer: My following comment/question is not meant to be disrespectful or argumentative in any way. I have the utmost respect for John – In fact, when I open the message board (which is usually several times a day), I first look for “sunburst’s” comments, because I have learned so much from his postings – but – I have been following this thread for several days, thoughts have been bouncing around in my head, and I have a question: I recently installed a dust collection system in my new shop. I placed it outside the shop area, in the garage (which was the compromise with my wife, which allowed me to build the shop, in the first place), and even in an adjacent room, the collector roared. I lined the closet with fiberglass insulation, and now I can barely hear it, even though it vents back into the shop, to avoid heat/cooling loss. Acoustic tiles full of holes would likely have had a similar effect.

Now, I realize that I’m stretching it a bit here, because the difference between raw, unfinished maple, and the same material, finished with whatever – sealer; shellac; lacquer; paint; peanut butter and honey, seems moot, but what would happen if I were to line the inside of a mandolin body with open-cell foam; soft cardboard full of holes; acoustic tile material; fiber-glass insulation – even suspend some of these materials from fine wires or mono-filament inside the sound chamber? Would the same thing happen that happened with my dust collector closet? If so, what is happening? Isn’t the sound being absorbed – not being allowed to come out through the f/round/oval holes, the same as the sound of the screaming motor not being allowed to re-enter my shop, or the roar of my truck engine not being allowed past the mufflers? If it isn’t being absorbed, then what is happening? Where is it going?

Gene

[Bill Snyder]

Isn’t the sound being absorbed – not being allowed to come out through the f/round/oval holes, the same as the sound of the screaming motor not being allowed to re-enter my shop, or the roar of my truck engine not being allowed past the mufflers? If it isn’t being absorbed, then what is happening? Where is it going?

Gene
Sound energy is converted to heat energy as it passes through different materials and the sound is absorbed.
I suspect that if anything, finishing the inside of an instrument would dampen the sound instead of improve it afterall one of the complaints of cheaper mandolins is the thick finish. I do not see where it would make a difference it the thick finish was split between the inside ond the outside.

[Bill Snyder]

Bill Hay check out the mandolin oddities in the Post a Picture section. You might get a few ideas.

[billhay4]

markishandsome,
Thanks for a gracioius, and constructive reply to my whiny post.
Dave Cohen told me that a violin shaped instrument would probably not sound good because it tends to split the air mass into two sections (correct me if I am misremembering you, Dave). I inferred from that that the shape of the inside did matter, but maybe only in gross terms.
It is obvious I need to do some research here. I have done some reading in this area before and have found a problem with what I have read. The physicists tend to present a lot of data and make conclusions in terms of acoustics, but they never go into the practical consequences for luthiers. So I am left with the question, "So?" after reading a technical paper. Part of my effort here was to try to get some of the more knowledgeable out there to venture suggestions in the very practical realm of lutherie.
Now, phantom4 raises the very real issue of sound dampening. If he can dampen the sound of his dust collection system, does a mahogony block dampen sound in a mandolin? What about a maple block? Or a certain shaped block? Or kerfed lining as opposed to solid lining? Or spruce lining vs. willow?
Another example of the never-ending nature of this. Last night I wondered why tonebars run the length of an instrument and cracks do, too. Why not braces across the top? Or round braces? I saw some curved ones on the message board some time ago that were intriguing.
I see the bottomless at the end of the pit.
Bill

[billhay4]

Bill,
Why isn't the sound energy inside the mandolin absorbed by the top and sides, etc? Is this because of the soundhole? or the nature of those materials? Does the shape of the interior help funnel the sound to the soundhole? Sound is waves. They have to reach the ears to be heard. They also can bounce off some materials and be absorbed by others. Can they be distorted, too? Do the waves get distorted by the soundholes? Absorbed by the instrument itelf? Send in a certain direction by the placement of the soundhole?
I realize these are novice questions, and to be frank I think I know the answers to some. But they do inform considerations of design, so I am posing them again here. After all, why are mandolins in either bowlback or F or A shapes? Is it merely historical accident (the influence of the lute, for example) or is there a real acoustical basis for these shapes?
Thanks for continuing to read these ramblings.
Bill

[markishandsome]

That's exactly what Dave said does NOT happen. He said (page 1)


the elongation of the violin body causes the sideways sloshing mode to occur at a considerably higher frequency than the longitudinal sloshing mode.

And here we have an example of physics-speak clouding the issue. The air chamber has many resonances which move the air around which impinges on our eardrums and creates the sensation of hearing something. When you pluck the mandolin strings (which have their own resonant frequencies determined by their length, weight and tension) the vibrations activate the various resonant modes of the soundboard, which in turn activate the air modes (the ones we hear). The air chamber only vibrates at certain resonant frequencies (these are the modes Dave's always talkin bout) but when you hit the strings you activate ALL of these modes at once. "how much" of each mode you activate is determined by the relationships between all the resonant frequencies of of the strings, soundboard and air chamber. It's all connected! An air chamber mode with a very high frequency (say a bazillion Hz) will not be very strongly activated by mandolin strings buzzing along at a few hundred Hz. Add to this the fact that becasue of the way the instrument is layed out, some modes do not radiate efficienty, which is to say the air inside the box is vibrating in such a way that it can't make it out of the soundholes and into your ear. Energy dumped into these non-radiating modes is lost. So if you want a loud instrument, you want to tune (somehow) the frequencies of the non-radiating modes so they do not couple well to the string vibrations. Conversely you want to tune the strongly radiating modes (especially the helmholz) so that they are strongly activated at the frequencies you would like to produce. Of course you can't completely eliminate undesired modes without screwing up your prefered modes, so it becomes a balancing act. A lady named Carleen Hutchins once said that the best place to put the helmholtz mode was right in the middle of the range of the open string frequencies of the instrument. This was all the notes you can play are resonable close to the "magic" resonant frequency of the air, sort of a sweet spot. Not everyone agreed with her, but it makes intuitive sense.

Anyway, it's the overall dimensions of the body that determine the air resonance frequencies, not the texture of the plates and sides. There's a difference between what physicists call "standing" waves and "traveling" waves. The modes we're discussing are standing waves, the whole wad of air inside the box vibrates all together, there simply isnt anything bouncing around inside that can be defleced by the blocks or the braces. If you put marshmallows in jello, it still jiggles. The air inside the kerfs in kerfed lining probably does not participate much in this vibration, but it wouldn;t if there was solid wood there either.

Sorry this was extremely longwinded, I've been thinking a lot about this stuff myself lately.

[Dave Cohen]

Uh, youse dismembered me.

Air modes do not "get split into two sections". You might be able to talk about "segments" of a single air mode, but a single air mode remains a single air mode, regardless of how many "segments" there are. Think of a given string harmonic; there are vibrating "segments" between each node. F'rexample, the second harmonic of an open string has a node approximately over the 12th fret, and the rest of the string on each side of the node can be thought of as two vibrating "segments". But the second harmonic is one solution to the equation of motion for the string, and has one characteristic frequency. With the air modes, there are some similarities. The first air mode is the Helmholtz resonance. Regardless of the shape of the cavity, it doesn't get split into more that one segment; it has no nodes, period. The second air mode is the longitudinal sloshing mode, which has a node approximately under the bridge. Nothing about the shape of the cavity changes that. The third air mode is a sideways sloshing mode, which has a node approximately along the center seam of the plates. Again, nothing about the shape of the cavity changes that. If you had a circular or cylindrical cavity, the longitudinal and sideways sloshing modes would be what we call "degenerate". That doesn't mean that they wear overcoats over nothing; it means that they have the same energy, and in this case the same frequency. If you elongate the cavity or body shape, you remove the degeneracy. The longitudinal sloshing mode moves to a lower frequency, and the sideways sloshing mode moves to a higher frequency. Please remember that they are two distinct modes from the start. As you elongate the body further into a violin shape, and pinch the body narrower in the c-bout, you further lower the frequency of the longitudinal sloshing mode, and further raise the frequency of the sideways sloshing mode. This stuff is potentially more important for violins, b/c there is more high frequency input from the "Helmholtz motion" of the drawn bow than there is from a single pick stroke. But even in the violin community there is a recognition that they pretty much have one air resonance to work with. The Helmholtz resonance and its' interaction with the lowest body modes is dominant in the low frequency sound radiation. At higher frequencies, there is a greater contribution from radiation from the [/I]outside of the instrument body.

Also, I don't think that I said that a violin shaped mandolin would necessarily sound bad; just different. Again, if a luthier were dedicated to working with that shape, (s)he could probably make it work well. Selling it might be another problem. Recall my comments above re the kidney bean-shaped mandolin.

For people having trouble understanding the literature, Tom Rossing wrote a series of three articles for American Lutherie[I] back in the late '80s. They are now in "The Big Red Book of American Lutherie", Volume Two (1988-1990). The first two were combined into "An Introduction to Guitar Acoustics", pp 124-134. The third is "Sound Radiation from Guitars", pp 144-152. The articles were written for lay readers, so there are lots of pictures and few equations. The few equations in the sound radiation article were presented in the most simplified form possible. No partial differential equations, I promise!

[billhay4]

Thanks a lot, Dave. We non-scientists really appreaciate it when we get an explanation we can understand. I am slowly getting it with your, and lots of others' help.
Bill

[Bill Snyder]

Bill Hay,
I claim no great knowledge of sound generation in an instrument. My post in responce to Gene's was more about what happens to sound as it passes through walls, etc. #I am currently the QC superintendent for an insulation contractor and we install some material for the sole purpose of sound attenuation. In addition a few years ago when I was still in construction I helped design and build a professional recording studio. That is when I learned about sound isolation and building sound proof (well almost sound proof) rooms.

[billhay4]

Well, I took Curious' advice and looked at the Oddities (http://www.mandolincafe.net/cgi-bin/ikonboard.cgi?act=ST;f=15;t=13416;st=25) thread. Sorry I've been placed in that category, but I can't say I didn't ask for it.
These are the ones I liked:
Bat Mando
Allen Beardsell
Yoni Goddess
Picasso
Van's instrument
Holst
Contadino
Butterfly
Arman
Kentucky (it isn't surprising that the state of Kentucky is shaped like a mandolin, now is it?)
Bill

[Bill Snyder]

I was not implying that you (or your yet to come mandolin design) are odd. I just thought that you might see something that sparked some interest or gave you an idea or two.
The first mandolin I built certainly was not normal.

[billhay4]

Well, Bill,
I am odd. How many people take on mandolin building as some sort of philosophical endeavor? Especially someone of my modest skills.
As for the to-come design, I have been batting around some ideas in my head, and it just may be a bit odd. We'll see how these ideas stand the test of time and the rigors of building.
I'll post a link to some of my ideas when they are fleshed out.
Thanks,
Bill

[JeffD]

This discussion reminds me of the AKC descriptions of particular breeds. If you had never seen the dog, could you draw a picture of him using the description in the breed standard?


I have heard differing opinions about the acoustic contribution of a scroll and points, but the concensus seems to be no effect. Someone here said in a different thread that a good maker can create an instrument with the desired sound in either A or F style.


So here is my idea - some enterprising luthier should come up with a snap-on scroll and points! #
http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

An A to F conversion kit! Before you aspirate your coffee laughing, consider for a second - would you buy one?

[billhay4]

Jeff,
There have been some converstions from A to F. I've run across a few of these in the vintage instruments thread. But no snap on's yet. Interesting idea.
I've thought of removable fingerboards, but hadn't thought of this.
I just read a paper by Lawrence Smart (a very respected Idaho luthier) who thinks that the scroll does contribute to the acoustic qualities of the instrument. Link Here (http://smart-instruments.com/gal95.html).
Some other odd ideas I've had include an offset V for the headstock to move the hand into a better playing position, a bridge with adjustable intonation, a double back to isolate the instrument from the body, slide in frets, a partially external head block, etc. Actually, I can't see any justification for the F-style of mandolin except aesthetics and tradition. These are powerful considerations, but are pretty much outside my realm of inquiry here. Other than a strap hanger, I can't see any reason for a scroll. Other than making it easy to use shorter pieces of rim material, I can't see any reason for points. I think my final design will be round, elliptical, or some variation on these. Structurally strong, creates the same interior volume, easily modified for ergonomic purposes.
None of these is fully thought out yet, so we'll how they stand the test of thought.
Bill

[Bill Snyder]

...a bridge with adjustable intonation...
Like this one?
http://www.lutherie.net/mando-matic.jpg
You can read a bit about this one in this thread. (http://www.mandolincafe.net/cgi-bin/ikonboard.cgi?act=ST;f=7;t=38817;hl=matic)
To save some time Paul Hostetter was the original poster of this picture and he says this bridge is no good for tone, etc. .

[Gibson A5]

Bill, I always thought the points were to keep the mando from slipping around while playing when you were sitting down and not using a strap. #I never heard anyone say this, but I just assumed that was what they were there for(except for the models with the point on top, maybe a lefty playing a rightie could use that one while sitting). #I have also thought of an A to F conversion using velcro(sp) on the attaching parts for easy installation and removal. #I often thought that it would be a good joke for the A only players.
Keep on Pickn'
Bill P.

[markishandsome]

I use the lower point to steady the instrument while seated, I don't see how the upper one could have the same functionality. Some players don't like the lower one because it stabs them in the thigh the way they hold it. Can't please everyone!

[Bing Cullen]

Several years ago at a mandolin orchestra festival in Perth Western Australia, a visiting madolin ensemble from New Zealand featured a spun off trio called Troika led by the then orchestra conductor who was Russian. His instrument was called a Russian mandolin. This was a 3 stringed instrumnet not unlike a balalaika, but with a round body and virtually flat top, but I believe a slightly bowled back #in the hands of the conductor..a virtuouso of enormous talent, it sounded wonderful and I have often thought I'd like to own one...maybe one day I'll visit Russia and get one. So 8 strings do #not necessarliy maketh a mandolin, nor scale length or tuning range. Incidentally he employed tremolo for a large part of his solos.

[Eugene]

Technically, that was not a mandolin, but a Russian domra. The Ukrainian domra even has four strings tuned g-d'-a'-e''.

[Patrick Killeen]

Here's a alternative arangement for frets that might be of interest from Novax Guitars (http://www.novaxguitars.com/)

It's an interesting idea, but I'm not convinced it would work well on a double strung instrument.

Patrick

[Patrick Killeen]

...and here's another instrument with fan frets, this time from Steve Hicks (http://www.stevehicksinstruments.com/luth.htm)

Patrick

[Dave Cohen]

Rolfe Gerhardt built at least one mandolin with the Novax fanned frets. He wasn't crazy about 'em, but the one I have seen and played "worked" fine. Intonation is not a particular problem. Getting used to the configuration takes some effort.

[Eugene]

As you've discovered, Patrick, fanning frets is nothing new in spite of the Novax patent. Frankly, I don't see the practicality unless to balance tone across a wide range of open strings, wider than mandolin. Also look into the "Brahms" guitar designed by the late David Rubio and championed by Paul Galbraith.

[billhay4]

I had seen the adjustable intonation bridge thread, and agree with Paul that it doesn't look very practical. I have wondered if there what another solution using a wooden or bone top, but I haven't given this a lot of thought yet, so I'm not sure if it can be done. May be overkill anyway as your real goal is to get a particular instrument intonated correctly once, not over and over. So, what you really need is a bridge that is custom fitted for that instrument at the beginning.
As for points, I suppose the lower point helps a bit. As to whether it is an essential design element, I'm not so sure. But the idea of something to help stabilize the instrument on the lap is worthy of thought. A point has a high cost, but some sort of indentation in the rim might work just as well.
Thanks for the input.
Bill

[markishandsome]

..and here's another instrument with fan frets, this time from Steve Hicks

That thing's wild! Looks like Salvador Dali's mandolin.


Incidentally he employed tremolo for a large part of his solos.

I don't know if tremolo is a defining characteristic of mandolins. Dick Dale does tremolo on electric guitar, you could play tremolo on a yellow dog if it had heavy enough strings on it, it just wouldn't sound as good as on a double course instrument.

[JeffD]

And don't forget all the tuner options. I found this on the thread about Portuguese Peacock tuners.


If you could put the tuners anywhere, where would be the most convenient?

[billhay4]

There have been some instruments with tuners at the tail. No headstock at all.
However, I think tuners are best at the head because they are out of the way. This necessitates a nut or zero fret, though.
Tuners could be much smaller, though, and much lighter, and still do the job. IMHO
Bill

[JeffD]

Well the ideal mandolin would come already tuned! http://www.mandolincafe.net/iB_html/non-cgi/emoticons/tounge.gif

[pelone]

To further clarify what goes into making up a mando I would think that the volume or cubic inches of the mando body would be a critical factor that contributes to the quality of tone. Just what is the cubic inch of, for instance, F Gibson and/or A Gibson? If one increases the size of the body does a resultant change occur? Is the tone quality more to the high and thin side or to the more mellow? I have read that the depth of the body may have an effect--how about what might occur if the body was 10% greater?

[billhay4]

I constantly get it wrong on this question and it is an important one. Depth does affect sound as does total volume.
According to Rick Turner, shape also affects sound.
Dave Cohen is the reigning authority on mandolin acoustics.
But translating the science into specifics is difficult as there are so many variables at play. This is one major reason most builders stick to the norm, I think.
Bill

[Bill Snyder]

Bill what is the norm? For most of the members of the Cafe the norm is an arched top/back mandolin with basically a tear drop shape with or with out points and a scroll added.
The norm 100 years ago was a smaller tear drop shape with a back made of several ribs and not quite as common but certainly widely available were guitar shaped mandolins.
They may sound a bit different but they all sound like mandolins.
I think ALMOST any wooden acoustical instrument using a 13-15 inch scale length, using commercially available mandolin strings and tuned gdae (or close to it) is going to sound like a mandolin. It may be too quiet or too tinny or ...., but I would expect its tone to be recognizable as a mandolin. It might not be marketable but if you are looking for marketable build f and a style carved top/back mandolins out of figured maple and tightly grained, even colored spruce. #http://www.mandolincafe.net/iB_html/non-cgi/emoticons/mandosmiley.gif

[pelone]

Bill Snyder--a couragous stand. I like the firm convictions and your attitude. Even though I am building mandos that probably do not conform to tradition, I am building them for myself with no thought to profit making. I am spreading them out to my daughters and son. My son, however is a bit of an F snob and has not embraced my design with the warmth that might be extended to an F. However--I continue to build because it is just so dang enjoyable. I may one day have the confidence to post a picture.

Picasso once said that he knew when he was painting well when he painted with the abandon of a child--with out fear of judgement and for enjoyment. I would suppose that innovation might be accomplished if builders just had the confidence to create with out thought of judgment.

[billhay4]

Pelone,
Show us your instruments, please.
Bill Snyder,
I agree with your post that within limits, a mandolin is roughly elliptical and most sound pretty much like mandolins.
I made this point in another thread, and made it badly, and was jumped on, but I still think the primary determinant of sound is the interior volume and not the shape (within limits).
There are other reasons for the shape, too. An oval is stronger than a circle in the long dimension, isn't it?
Also, an oval instrument is easier to play up the fingerboard.
Finally, there are mathematical limits on the size of a mandolin, aren't there? Scale length plus desired bridge placement on the top tend to limit the length of a mandolin body. Of course, you can make the instrument have a very long scale, but it becomes difficult to play then. And you can increase volume by increasing depth, but the makes major differences in sound.
So, there may be reasons that there is a norm. I would not challenge this, only seek to determine if those reasons are musically or structurally valid.
Bill