# Instruments and Equipment > Builders and Repair >  The neck's contribution to tone quality

## DHopkins

After someone found that Stradivarius viola recently, the news story quoted someone as saying the instrument wouldn't achieve it's full potential for at least 5 years because it would need to be "broken in."  A guitar buddy of mine and I were discussing that process.  The question came up as to how much the neck of a mandolin (or guitar, for that matter) contributes to the tone.  Assuming it's made of an acceptable wood, is there a difference in the tone different neck woods would produce? 

I'm inclined to think it's not a substantial amount but I don't have anything to back that up.  Any help?

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Mandoplumb

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## sunburst

I don't know if neck wood has a contribution to mandolin sound. Neck mass and stiffness seem to have an effect.
I can tell you this:
When I worked at the banjo "factory", I would often be sanding away, sitting at my work bench when the boss strung up a new banjo. I couldn't see him from where I was, but I could hear the banjo. Almost all of them had either maple or walnut necks, and I could tell which wood it was about 70% of the time just from hearing it in the next room. Not too scientific, but it was  a blind test of sorts, so perhaps the neck wood makes a difference in banjo sound. Can we automatically assume that applies to mandolins too? I'd say no, we can't assume that.

(For the record, I suspect that if other not-so-scientifically-inclined builders had had that experience, some would say "Yes, neck wood definitely makes a difference in sound". Things like that happen "all the time".)

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hank, 

jhowell, 

Michael Weaver

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## HoGo

I agree with John, those long thin banjar necks seem to do something with the tone.
I suspect that mandolin necks' effect, being quite short and stiff, is much smaller. Ibelieve they don't add to the sound but rather they may filter some frequencies of strings energy as they are anchored on the neck and by this affect resulting sound. I like to string mandolins in the white and adjust with strings on and in few mandolins where I left neck quite a bit oversized (like neck not trimmed to edges of fingerboard and heel still shaped by an axe) I noticed some changes in tone when I removed the wood. One notable change that I still remember was when I removed some wood from neck heel (the curved part) on my #7. But once the neck is close to "standard" dimensions not much happens...

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hank, 

Hendrik Ahrend, 

jhowell, 

kjcole

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## fscotte

Everything on a mandolin affects the sound, it's just a matter of being able to hear it or measure it.  If it vibrates, it creates sound because it moves air molecules.  Moving air molecules produce sound.

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hank, 

Perry Babasin

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## Larry Simonson

The fact that many players attach their electronic tuners to the headstock tell us that the neck is indeed a moving part of the instrument and thus is involved in the total sound producing mechanism.

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theCOOP

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## Pete Jenner

Yes but... a neck isn't a soundboard in case you haven't noticed.
It's a stick ...it sounds like a stick.

What's brown and sticky?

...a stick.

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Jim Adwell

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## sunburst

Another thing that happens "all the time" is: someone makes the leap from something vibrating to it making a significant contribution to sound production. All parts of a mandolin vibrate (a clip-on tuner will pick up notes anywhere we can manage to clip it), but sometimes they are stealing string energy from the parts that _do_ contribute significantly to sound production. They may be acting as filters when they do that, but they may just be vibrating with no particular effect on sound. We don't always know.

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hank, 

Hendrik Ahrend, 

JEStanek, 

jhowell, 

Jim Adwell, 

sblock

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## Larry Simonson

"Yes but... a neck isn't a soundboard in case you haven't noticed"  Thanks Pete, That thought never occurred to me.

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Pete Jenner

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## kkmm

I am no expert, just talk about my recent experience. I built a tenor ukulele 2 years ago with very thick neck and thick braces.  The result is a dead sounding instrument. Recently, I cut off the back, trimmed down the braces to 1/3 of what they were and the sound improved greatly. Then I thinned the neck as much as I could and it sounds even better, very noticeable. Then I applied a thick finish on the neck, the tone went down with it. I scraped off this finish to restore the tone and just applied two thin coats of danish oils. At present time, this ukulele sounds as good as I expect it to be, comparable to the ones with solid top in the store. I don't know if this is true for mandolins with high tension steel strings or not.

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## pfox14

I don't know how a 400 year old Strad would still need another 5 years to "break in"...that makes no sense. I don't the neck of an instrument contributes much to tone. Its main function is to remain rigid under the pressure of the strings. Since the wood is thick and rigid, it's not vibrating and not producing sound. The vibrating parts of any instrument is what is producing sound, so the body woods, especially the top and the strings are doing 95% of the work.

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## Willie Poole

I at one time posted on here that I read where Roger Siminoff said that more wood on the neck and headstock of his banjos kept the sound from traveling up the neck and therefore allowed the banjo to sound better...I got a few replies saying that it wasn`t true...SO?....I am not a builder so I don`t really know but it sounds quite possible to me.......

    Willie

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## sunburst

Sound doesn't "travel up the neck" exactly. The vibrations we feel when we touch the headstock of an instrument are usually the whole body bending modes of motion. The whole length of the instrument (including the neck, obviously) bends like a bar. Depending on the length, mass, and stiffness of the instruments, the frequency of the main bending mode may or may not be in the range of the notes that the instruments produces, and when it is it can cause problems. Electric bass guitars can have "dead spots", or notes that are much weaker than other notes. That can be caused by a bending mode "stealing" string energy that would otherwise remain longer in the string so that the pickup could send it to the amplifier rather than being wasted "vibrating the neck".
In smaller instruments, like mandolins, the bending mode frequencies are usually out of the range of the notes produced by the strings, and out goal as builders can be said to include _reducing or minimizing_ the tendency of the neck to vibrate and steal string energy, since it is the body of the instrument that converts string energy to sound.
(There may be some high frequency compression sound waves that "travel up the neck", but I'm not sure about that, and if there are, I suspect the frequencies would be high enough to not interfere significantly with sound production.)

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Cheryl Watson, 

hank, 

jhowell, 

sblock

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## kjcole

Necks act as a load to the traveling waves that will filter the energy (they can't add energy) according to the impedance (sort of a frequency-dependent 'resistance') match/mismatch between the neck and body.  This basically means that some frequencies will pass with varying effectiveness (and the neck will resonate) and some frequencies will be reflected back to the body.  As the neck vibrates the energy can go back the other way too.  So, it is complex (duh).  Generally though, short (less massive) and stiff (mandolin) necks will reflect the low frequencies, longer necks (e.g., banjos) will let more of the lower frequencies pass the neck/pot interface.  Mine sounds different if I switch my heavier D tuners to regular tuners.  I'll let you all tell me how small of a change in neck characteristics can be perceived in a mandolin.  With sensitive enough equipment we can measure just about any change of material size and properties.  The real question is if we can perceive changes in sound reliably.

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CeeCee_C, 

hank

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## Dave Cohen

> Necks act as a load to the traveling waves that will filter the energy (they can't add energy) according to the impedance (sort of a frequency-dependent 'resistance') match/mismatch between the neck and body.  This basically means that some frequencies will pass with varying effectiveness (and the neck will resonate) and some frequencies will be reflected back to the body.  As the neck vibrates the energy can go back the other way too.  So, it is complex (duh).  Generally though, short (less massive) and stiff (mandolin) necks will reflect the low frequencies, longer necks (e.g., banjos) will let more of the lower frequencies pass the neck/pot interface.  Mine sounds different if I switch my heavier D tuners to regular tuners.  I'll let you all tell me how small of a change in neck characteristics can be perceived in a mandolin.  With sensitive enough equipment we can measure just about any change of material size and properties.  The real question is if we can perceive changes in sound reliably.


You are being guided by your physiology and neuroscience background.  What you say is sorta correct, except for the part about the traveling waves.  With mandolins, guitars, and banjos, we are dealing with wave motions of much longer wavelengths in elastic solids.  The longest wavelengths are on the order of twice the dimensions of the instrument itself.  So within one or a few reflections, standing wave patterns are established.  They are called _normal modes_ of vibration.

John Hamlett got closer to what actually happens when he mentioned the whole-body bending motions of neck plus body.  The lowest frequency mode, sometimes called _mode 1_ in guitars and mandolins, is a bending motion of the whole neck plus body, much like the first bending motion of a simply supported bar or beam - kinda like the first harmonic (aka fundamental) of a string, except that the ends move.  That one occurs at about 150 Hz, a bit too low to interact with any other modes.  So that mode doesn't do much of anything.  It is neither a waster, nor is it close enough in frequency to interact with any other modes.

The second mode, called _mode 2_, has a node at or near the heel of the body of a mandolin.  That one occurred up around 380-400 Hz, in one mandolin that I studied.  That put it near or even overlapping with the upper "trampoline" (aka "(0,0)" or "T(1,1)") body mode.  There was some band broadening due to that interaction.  I looked at the same modes in a guitar, and did not find such a strong interaction.  In that guitar, the upper trampoline mode was at ~200 Hz, and mode 2 was a bit higher.  Didn't see any apparent band broadening there, though I haven't done the plots yet.  These interactions depend on how close the frequencies of the upper trampoline mode and mode 2 are to each other. I need to look at a few more instruments before I can be sure of anything.  I am also trying to fit the data to a model.  I solved the ODEs, but haven't had time to crunch numbers.  One thing that I definitely can say is that a small change in a neck will not make much of a change in a given instrument.  You need a profoundly different neck to make a significant difference in mode 2.  To increase the mode 2 frequency by 30 Hz would require a neck that would be 50% stiffer and maybe 25% lighter - a really tall order.

http://www.Cohenmando.com/

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CeeCee_C, 

Cheryl Watson, 

Dave Greenspoon, 

davidb1, 

fatt-dad, 

hank, 

JEStanek, 

jhowell, 

kjcole, 

Pete Brown, 

Pete Jenner, 

sblock, 

tburcham

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## Stephen Perry

Neck resonance and the clarity of that resonance seem important to me.  For example, simply tuning four points to the same pitch on a violin neck makes a substantial difference in the "noise" in the sound produced.  I strongly suspect there's a good deal more that can be done along those lines.

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hank

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## barry k

I'm just laying back on this one....enjoy...BK

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## vic-victor

> I could tell which wood it was about 70% of the time just from hearing it in the next room. Not too scientific, but it was  a blind test of sorts, so perhaps the neck wood makes a difference in banjo sound.


So, which was one better, maple or walnut? Thanks.

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## Jim Adwell

My guess is that the maple neck banjos were louder and clearer, with more sustain (if that's a word one can even apply to a banjo).  :Smile:

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## sunburst

> So, which was one better, maple or walnut? Thanks.


Neither was better, just different enough for me to (apparently) tell the difference some of the time. The very fact that I guessed wrong sometimes should indicate how little difference there was.

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hank

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## j. condino

I've been watching this thread for a bit.

There is a pretty simple answer to the original question of "the neck's contribution to tone  quality". "The Salt Creek Test": Build your next mandolin and leave the neck as a big uncut square. Finish all of the rest of the build and string it up. Play the mandolin the whole time you are carving the neck down to the finished size (Salt Creek?). If you can hear any difference, then you just answered the question for your ears. I do this for almost all of my instruments.  On a mandolin, I can hear three distinct differences in the voice while carving the neck. Some people can't hear anything; everyone hears a little different.

Similar to John, I used to work in a factory. The instruments were generally built to whatever spec the paying customer wanted; not always the one you or I would chose. All of the mandolin and guitar necks were bolted on. They made necks out of mahogany, maple, myrtle, walnut, and a few other materials- most of them cnc cut to the same spec. I got out the old shaper jigs and also built them out of Douglas fir and rosewood. 

In my eager quest for knowledge, often after everybody was long gone and I was the only guy in the shop, I'd stay there half the night and dissassemble the whole day's worth of a half dozen or more instruments, swap out and interchange all of the necks. I did that to 4-500 instruments over the course of a year and  heard consistent similar results and developed some very specific opinions. For a lot of other folks at the same shop it was simple- " I want the one with the brown neck, red binding, and the unicorn inlayed on the fingerboard...." I don't think they played Salt Creek... ever.... :Wink: 

j.
www.condino.com

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hank, 

Tom Haywood

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## kkmm

I experienced the same as "grandcanyonminstrel" with my tenor ukulele build. The obvious difference was in the volume. My dumb  guess (simply based on physic) is the string vibration at the nut gets transferred to the neck then the body at the joint. A very thickneck will dampen the vibration from that direction.
I will carry a simple experiment to see how this goes:  lock the neck of my ukulele in something that reduce the neck vibration, then play and see if there is any difference. The same could be done to mandolin.

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## Dave Cohen

> I experienced the same as "grandcanyonminstrel" with my tenor ukulele build. The obvious difference was in the volume. My dumb  guess (simply based on physic) is the string vibration at the nut gets transferred to the neck then the body at the joint. A very thickneck will dampen the vibration from that direction.
> I will carry a simple experiment to see how this goes:  lock the neck of my ukulele in something that reduce the neck vibration, then play and see if there is any difference. The same could be done to mandolin.


Couple of things.  One is that string vibrations pretty much stay in the string.  They are reflected back and forth from nut to bridge saddle, b/c the impedanceces at the nut and saddle are very different than that within the string material.  The string motion exerts both longitudinal and tangential force pulses every time the sting passes through zero amplitude at the antinode(s).  Those force pulses are exerted on the bridge and the nut, and the string loses _energy_ to the extent that the bridge and the nut move in response to the force pulses.

The other thing is that a very thick neck will not necessarily dampen vibrations (in the neck) any more than a thin one will.  The amount of damping depends more on the internal damping of the material than on other factors such as dimensions.  What the different dimensions do is change the mass and the overall stiffness, and those parameters in turn change the _frequencies_ at which the vibrations occur.  More mass lowers frquencies, but greater stiffness raises frequencies.  In practice with wood plates, stiffness tends to win out, so removing material lowers frequencies.  I'm not as sure with necks.  Some of the experiments I have been doing in the last few years involve a CF composite shell neck, which actually _is_ 50% stiffer and ~40% lighter than the other (conventional) neck used.  With the CF neck, the frequency shifts I have seen appear to be more due to mass than to stiffness.  Again, I won't know for sure until I crunch numbers.

http://www.Cohenmando.com/

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hank, 

Jim Adwell

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## Shelby Eicher

I tend to say that wood choice in a neck makes a difference in tonal quality. My experience with violin bows makes me think that all contributing factors are reflected in the end result. The stick of a bow resonates and contributes to the sound of the fiddle. When I bow shop, I can tell a difference in tonal qualities: deepness, clarity, brightness, warmth, articulation of notes, etc. The vibration of the string and hair resonate through the stick which has no contact with the string itself but produces noticeable differences in tone.

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hank

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## Stephen Perry

Shelby is onto it.

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hank

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## David Lewis

On a guitar at least, the maple fretboard gives a brighter snappier tone. Rosewood is warmer.

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## Ivan Kelsall

From Peter Jenner -_ " What's brown and sticky ? -...a stick."_. Oh Peter !,you are a one !!!!. You've lived upside down for too long mate !. :Grin: 
 I'm not sure that i'd go so far as to say that the neck contributes 'directly' to the sound from any instrument,but they certainly do vibrate in concert with the main body of the instrument. Both my mandolins feel 'alive' when i play them & it's a great feeling, as though they really are responding fully to my efforts. My Stelling banjo neck has a life all it's own when i play it,it really does vibrate,& again,it's a nice feeling rather than having a totally inert instrument (as well as player !). I suppose if the neck of an instrument does vibrate (resonate),then it must have a resonant frequency.However,i think that it would be hard to measure this frequency, totally divorced from the resonance of the instrument as a whole. I suspect it would be sub-sonic,but nevertheless,it would have some influence on the resonance of the 'whole' & a such affect the sound of the 'whole',as has been stated above.
  I understand what Shelby says as well. The strings & bow/bowhair must impart vibrations of their own to the 'whole' set of vibrations going on, which are then transferred to the body of the Violin (for example) via the bridge,which itself will have it's own resonant frequency to add to the mix. Change any one of these factors & you change the 'whole',otherwise all the experiments into 'acoustics' in instruments over centuries, would have been pointless - i think i'll buy a Trumpet !, :Frown: 
                                                                                                                                      Ivan :Chicken:

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## Dave Cohen

> From Peter Jenner -_ " What's brown and sticky ? -...a stick."_. Oh Peter !,you are a one !!!!. You've lived upside down for too long mate !.
>  I'm not sure that i'd go so far as to say that the neck contributes 'directly' to the sound from any instrument,but they certainly do vibrate in concert with the main body of the instrument. Both my mandolins feel 'alive' when i play them & it's a great feeling, as though they really are responding fully to my efforts. My Stelling banjo neck has a life all it's own when i play it,it really does vibrate,& again,it's a nice feeling rather than having a totally inert instrument (as well as player !). I suppose if the neck of an instrument does vibrate (resonate),then it must have a resonant frequency.However,i think that it would be hard to measure this frequency, totally divorced from the resonance of the instrument as a whole. I suspect it would be sub-sonic,but nevertheless,it would have some influence on the resonance of the 'whole' & a such affect the sound of the 'whole',as has been stated above.
>   I understand what Shelby says as well. The strings & bow/bowhair must impart vibrations of their own to the 'whole' set of vibrations going on, which are then transferred to the body of the Violin (for example) via the bridge,which itself will have it's own resonant frequency to add to the mix. Change any one of these factors & you change the 'whole',otherwise all the experiments into 'acoustics' in instruments over centuries, would have been pointless - i think i'll buy a Trumpet !,
>                                                                                                                                       Ivan


Necks have not just one resonant frequency, but many resonant frequencies.  My first post in this thread was about the first two resonant frequencies in a mandolin and a guitar.  Not only did I already measure those frequencies, as well as others, but I also imaged the motions with interferometry.  The term "subsonic", usually implies frquencies outside the limits of human hearing.  115 Hz and 400 Hz are well within the limits of human hearing; The low C on a manodcello or 'violoncello is 65 Hz.  However, the amplitudes of the neck motions are frequently about an order of magnitude smaller than the amplitudes of plate motions in the instrument body.  Also, the neck motions do not by themselves couple directly with an air resonance,  At least not as far as I have observed.

I did the above experiments on a single mandolin body with two interchangeable necks.  One was a conventional neck - w/ a conventional adjustable truss rod and no CF reinforcement,  The other neck was a hollow CF shell, about 50% stiffer and 80 grams lighter than the conventional neck.  There were observable physical differences between the two necks.  Also a difference in sound that I think most listeners would be able to discern.  It should be kept in mind that the two necks described are profoundly different physically.  In the case of a true double blind test with two conventional interchangeable necks, say one made of walnut and one of maple, I would be very surprised if anyone were able to distinguish between the two at any level better than wild guessing.  For one thing, maple and walnut have similar average densities and similar average Young's moduli.

http://www.Cohenmando.com/

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## Willie Poole

So I guess the final answer is that the necks can make a difference but most of us would not be able to hear it, is that about right? Not that I really care because I am no builder bit I do like to absorb as much info as I can about what makes mandolins sound like they do...

   A good post and interesting to say the least....

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## bratsche

Just FWIW and for your info, here is a site that appears to "rate" various exotic hardwood species along a tonal spectrum from warm to bright, for use in guitar necks.

bratsche

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## mandobassman

> The fact that many players attach their electronic tuners to the headstock tell us that the neck is indeed a moving part of the instrument and thus is involved in the total sound producing mechanism.


You can attach you electronic tuner to the strap and it will work just fine.  Is that a "moving part of the instrument" as well?

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## fscotte

Anything that moves makes sound.  Strap included.  Even the legs of a spider makes sound.

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## Hendrik Ahrend

> On a guitar at least, the maple fretboard gives a brighter snappier tone. Rosewood is warmer.


... and an ebony fretboard sounds again warmer, I found. I've never played a Martin D-21 (Brazilian rosewood fretboard and, well, bridge) that sounded like a D-28 (ebony fingerboard & bridge); played many of both.

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## hank

Thread wake up time.  I'm back thinking about necks again and have some new thoughts to turn over among you.  I look at the neck and its connection to the body more along the lines of vibration transmission between the the string ends  I'm sure I'm over simplifying the reality of the mechanics at work here but wouldn't a tuning forks handle act in a similar way.  The handle is vibrating as well as the prongs as they move alternately in a lateral motion.  The low amplitude stronger vibration in the handle is not dampened by your hand while the the high amplitude weaker vibration of the prongs are easily dampened.  This is why the transmission of vibration from the fork prongs is through the handle to a secondary sound radiator.  The low impedance pathway between the alternating cycles of prongs in the handle increases the strength of the driving force that is available at it's base.  Most of us think of reducing resistance in the vibration transmission from the bridge to the top plate but poor fitting connections between other parts with soft curing glues increases the impedance of the nut/fret neck circuit of vibrations back to the body of the instrument completing the low impedance path.  Even though the top plate is the main radiator of sound with it's air coupling to the back plate it's best performance is dependent on the other parts staying in communication with it in a low impedance circuit.

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## Tavy

> Anything that moves makes sound.  Strap included.  Even the legs of a spider makes sound.


I'm going to disagree with that somewhat, and with Hank in post #33:

I'm firmly in the camp that the only thing you want moving, are those parts that actually produce sound: and that means the top and to a lesser extent the back.  Everything else would ideally be the proverbial "immovable object", if it transparently transmits vibrations to the top and back, that's fine and dandy, but ultimately vibration in all the other parts are really just creating waste heat.

Discuss  :Wink:

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hank

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## kkmm

> but ultimately vibration in all the other parts are really just creating waste heat.


OK, that should nailed it. "vibration in all other parts" means some energy are wasted in these "immovable objects" instead of making the top & back vibrating. And this does reduce the sound volume (and the tone changes either for better or worst).

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hank

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## Willie Poole

Some years ago I read an article that said that  Geoff Stelling and other builders would clamp different size pieces of wood on the head stock of banjos to find the best sound they would produce and then make the neck and head stock with that amount of wood because they believed that sound does travel out through the neck and to the peghead.....I had never given any thought to this since I don`t build any  instruments but just thought I would throw this in and maybe add some insight to the OP`s question....As I said I read it somewhere and don`t know first hard if it is a fact...

    Willie

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hank

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## fscotte

> I'm going to disagree with that somewhat, and with Hank in post #33:
> 
> I'm firmly in the camp that the only thing you want moving, are those parts that actually produce sound: and that means the top and to a lesser extent the back.  Everything else would ideally be the proverbial "immovable object", if it transparently transmits vibrations to the top and back, that's fine and dandy, but ultimately vibration in all the other parts are really just creating waste heat.
> 
> Discuss


If it moves, it moves air molecules, which creates pressure within the air.  That creates sound, whether you can hear it or not is the question.  If you feel any part of the mandolin vibrating, then it's creating sound.  Every mandolin I've ever played vibrates as a whole, with no dead parts, so the whole thing is moving air molecules.  Again, whether you can hear it or not is another issue.

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hank

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## hank

I have noticed that better built mandolins seem to not only have better richer tone color but noticeably better sustain unless they have been set up with extreme break angles.  Years back I had a mandolin improve in both volume and sustain after adding tension at the adjustment nut that had little to no tension on it.  The real wasted energy is that absorbed into loose parts and bad connections of parts.  This is where the resistance can be reduced from the pulses running through the circuit of vibration.  As long as the amplitude of the vibration is low there is little effect on the air to produce much sound but the timbre and sustain of the existing tone chamber are sometimes improved unless there is a problem with the frequency causing unwanted harmonic or sympathetic vibrations in the circuit.  The ideal situation is management of the vibration not suspension of it.  My background in RotorWing systems and airframe taught me this a long time ago.  Accelerometer study often revealed movement of known nodes after repair changed the mass and stiffness of the structure only in a small area.  You had to look at the system of vibration as a whole and their effect on each other not the individual components working in isolation.

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## Marty Jacobson

> I have noticed that better built mandolins seem to not only have better richer tone color but noticeably better sustain unless they have been set up with extreme break angles.


Does 21+ degrees count as extreme? :-)

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## fscotte

Marty, everyone I've seen with your mandolins appear to be playing effortlessly and enjoying the experience immensely.

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## Marty Jacobson

> Marty, everyone I've seen with your mandolins appear to be playing effortlessly and enjoying the experience immensely.


Let's just say I made them an offer they can't refuse.

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Rick Jones

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## hank

Thank you Marty, I was hoping to hear from you in this discussion.  I respect your opinion and thoughts about what you have learned taking a path less traveled.  I am always pleasantly surprised by you artistry and unique approach to create a great mandolin.  My observation of the effect of greater break angles is of F5 copies looking for more cutting power in a Bluegrass chest thumpathon.  Your creations are pretty far from that mold.  My desire is to not find fault with your designs, break angles or customer satisfaction but to get knowledgeable forward thinking luthiers like yourself to help us understand what truly is important about putting these parts into a unified whole.  If you think your neck parts are void of this circuitry of vibration and are only active at the business end of the bridge, top and rear plate with the rest of the mandolin in a null without continuity. I'm listening.

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## Marty Jacobson

> Thank you Marty, I was hoping to hear from you in this discussion.  I respect your opinion and thoughts about what you have learned taking a path less traveled.  I am always pleasantly surprised by you artistry and unique approach to create a great mandolin.  My observation of the effect of greater break angles is of F5 copies looking for more cutting power in a Bluegrass chest thumpathon.  Your creations are pretty far from that mold.  My desire is to not find fault with your designs, break angles or customer satisfaction but to get knowledgeable forward thinking luthiers like yourself to help us understand what truly is important about putting these parts into a unified whole.  If you think your neck parts are void of this circuitry of vibration and are only active at the business end of the bridge, top and rear plate with the rest of the mandolin in a null without continuity. I'm listening.


Hi Hank, I didn't take anything you said as disparaging. I have no idea what the neck does to the tone, but my feeling is that whatever it is, it's somewhere between negligible and subtle. I do change break angles to get different kinds of tonal properties, but I think that has to do more with the arching than the neck itself.
As far as my process goes, the neck is a handle - it has to perform an ergonomic function, not an acoustic one. I know that must be an oversimplification, but it's so far down the list of things to fiddle with that I suspect it'll stay that way for me.
The neck is actually one of the things I've spent the most time on, but it's all about manufacturing, stability, and ergonomics. It never even occured to me to change something about the neck in pursuit of a certain tonal trait (aside from break angle to allow a swoopier plate or less break angle for a flatter plate).

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hank, 

Randolph, 

Ron McMillan

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## Polecat

I'm not a builder, but I've read this thread with great interest. How much the neck influences the perceived tone is, I suspect, impossible to quantify, and I believe that Marty's comment that 


> it's all about manufacturing, stability, and ergonomics


is pretty much right. On the other hand, what is beyond doubt for me is that the mass of the neck affects sustain to a very great extent. Fender markets a  device called a fatfinger, which certainly works to increase sustain, which you can easily check without buying one - just clamp a G-cramp to the headstock and hit the open strings - the difference is quite surprising (it upsets the balance of the instrument pretty badly, too, so it's not very practical). I presume that it works by increasing the inertia of the whole neck, so that more energy stays in the vibrating strings. Consequently, it seems reasonable to me that a chunkier neck made of a denser, stiffer wood would have a similar effect.

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hank

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## sblock

It seems to me that many of the responses in this thread may be barking up the wrong tree. Of course, virtually every single part of the mandolin contributes to its overall tone quality, to some degree or other.  All parts add some mass, and perhaps also a bit of stiffness and damping.  And the mass, stiffness, and damping -- along with physical coupling among the separate parts -- are what give rise to mechanical vibrations, and therefore to the sound and timbre.  The proper question to ask is HOW MUCH does the neck contribute, relative to the other major wooden parts, like the top, back, sides, and bridge.  And the answer, which I really can't imagine is very controversial among luthiers, is that the neck contributes _very little_ to the projected sound, especially compared to the top, back, sides or bridge.  The qualities of the top, back, sides and bridge matter _a whole lot_ more, in fact. 

Will a more massive neck affect sustain?  Yeah, a bit.  But the sustain mostly comes from how the string energy gets shared with the body, and with the damping associated with its various resonances.  So, does the neck participate in that energy sharing?  Yeah, quite a bit (since it holds the string taught!), but that part of its function is similar from one neck to the next.  There is just not a lot of "room for maneuver" in neck _acoustical_ properties.  What matters much more for the mandolin neck are its _ergonomic_ properties (size and shape under the hand), as others have already expressed so well.

Put another way, if you want to improve the sound of a mandolin, there are other, much better ways to go about doing it than adjusting the neck wood/shape, or neck-body joint, or fingerboard.  There is just not much gain to be had there.  Not so for the other wooden parts: the top, back, sides, and bridge.  These things exert a much more dramatic effect.

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hank, 

Jim Adwell, 

peter.coombe

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## chris storz

^^That. Like just about any other stringed instrument the ergonomics of the neck have a far larger affect on the sound than the actual "acoustical properties" of the wood that the neck is made of, because the biggest determiner of sound is in your fingers. How the neck requires you to angle your fingers or how much force you have to exert to get a good tone. These factors are what matter.

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## Larry Simonson

Most everyone who has had a string break knows that the instrument's other strings will go sharp.  I believe this result is due to the relaxing of the entire instrument and the extent to this sharpening is related to the overall flexibility of the instrument.  Perhaps the stiffness of the neck is a major player.  The extent of sharpening is a objective measurement of a given instrument and I think it would be interesting to get a data base on many instruments and see if there is any correlation to tone quality as perceived by an experienced   listener and the flexibility of the instrument.  One can get somewhat of a measure of flexibility using a decent tuner to measure how much sharpening occurs when one takes the tension off a string or two, starting with an in-tune instrument.

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hank, 

Tom Haywood

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## hank

Maybe the reason necks seem so boring to many builders is that standard practices for successful construction of them and body connections have been worked out for a very long time.  Why mess around with something if it isn't broken?  As sblock and Marty point out the effect to the instrument is small if you follow the successful methods standardized today from great luthiers from the past.  Following commonly used practices, wood choice and eccentricities of shape on necks are more structural/ergonomically prioritized than sound shaping.  I understand this and am not suggesting anything other than contemplation of why tight neck connections and particular glues are desirable in a build no matter what wood choice is made.
  As an example of departure from stereotypical thinking is Nigel Forster's cantilever neck arch top guitars.  His bold departure from standard guitar construction in this model is a good visual representation of high energy low amplitude vibration transferred to the secondary high amplitude radiating acoustic moving plate.  Nigels method of driving his bridge/top plate is very similar to holding the ball at the base of a tuning fork to a tabletop to hear the low amplitude vibration.  The neck like a complete solid body electric guitar bolted to an acoustic guitar with a single point of vibrational energy transfer.

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## theCOOP

A response to the original post:

Imagine if balsa wood cod stand up to the stress of the strings...how do think the instrument would sound?

I'm forming my opinion as I type this. I don't think the sound would be as complex as with a hardwood neck. Imagine if tin foil was a suitable medium for your work truck's frame, how it would sound and feel coming down the road.

I just think there's something to be said for mass-damping

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## Tavy

> A response to the original post:
> 
> Imagine if balsa wood cod stand up to the stress of the strings...how do think the instrument would sound?


Neapolitan bowlbacks and many early flatbacks have necks made from laminated spruce with a hardwood veneer wrapped around.  They're as light as a feather and don't sound noticeably better/worse than similar later instruments with heavier hardwood necks.  As others have said, don't over-think it, it's a handle guys  :Wink:

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## theCOOP

> Neapolitan bowlbacks and many early flatbacks have necks made from laminated spruce with a hardwood veneer wrapped around.  They're as light as a feather and don't sound noticeably better/worse than similar later instruments with heavier hardwood necks.  As others have said, don't over-think it, it's a handle guys


Yeah, but there's still substantial (imo) mass dampening effect inherent in spruce. It was likely laminated for strength like an engineered floor joist. I would describe balsa as spongelike.

Do we know why they used laminated spruce with a hardwood veneer, rather than hardwood or rather than just laminated spruce without the veneer?

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hank

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## Tavy

> Yeah, but there's still substantial (imo) mass dampening effect inherent in spruce. It was likely laminated for strength like an engineered floor joist. I would describe balsa as spongelike.
> 
> Do we know why they used laminated spruce with a hardwood veneer, rather than hardwood or rather than just laminated spruce without the veneer?


Low cost and low weight (easy to hold against your body with no strap).  Without the veneer the spruce would be unlikely to survive much handling I would think.  Also trivial to carve to shape where the bowl joins on to the neck (there's no separate neck block) unlike harder woods where the carving would be a significant amount of work - all hand tools for that stuff back then too.

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hank

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## Jim Adwell

I've made several instruments with softwood necks.  I can't tell any difference in sound, but the softwood necks dent a lot more easily.   I have an acoustic guitar that started out with a canarywood neck which I eventually replaced with an Atlantic white cedar neck (bolt-on necks) as an experiment.  There may be some minor difference in sound between the two necks, but I can't hear it if there is.

In fact, I just made a 3/4 size guitar completely out of western red cedar, neck, top, sides, back, everything but the fingerboard and peghead veneer, which are aspen because I couldn't get any holly locally and I want white wood.  It's going to get beat up eventually and the fingerboard will wear out faster than normal, but it looks pretty cool.  It even sounds like a guitar.  :Wink:

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hank

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## Tavy

> I've made several instruments with softwood necks.  I can't tell any difference in sound, but the softwood necks dent a lot more easily.   I have an acoustic guitar that started out with a canarywood neck which I eventually replaced with an Atlantic white cedar neck (bolt-on necks) as an experiment.  There may be some minor difference in sound between the two necks, but I can't hear it if there is.
> 
> In fact, I just made a 3/4 size guitar completely out of western red cedar, neck, top, sides, back, everything but the fingerboard and peghead veneer, which are aspen because I couldn't get any holly locally and I want white wood.  It's going to get beat up eventually and the fingerboard will wear out faster than normal, but it looks pretty cool.  It even sounds like a guitar.


And let's not forget James Condino's "Cricket" which I believe was all recycled Doug Fir.

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hank, 

Jim Adwell

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## sblock

> Yeah, but there's still substantial (imo) mass dampening effect inherent in spruce. It was likely laminated for strength like an engineered floor joist. I would describe balsa as spongelike.


Sorry, I don't intend to come across as pedantic, but there's really no such thing, in physics, as "mass dampening."  Yes, there is a thing called "mass" (this causes inertia, and the resistance to accelerating forces). And yes, there is a thing called "dampening" (this measures the absorption of vibrational energy, and its conversion to heat).  But mass does not cause the dampening, _per se_, and the dampening does not depend upon mass.  These things are entirely separate, _independent_ quantities in the equations that describe the motion of vibrating objects, like instrument bodies, strings, speakers, etc.  

If you add mass to a vibrating object, you tend to lower its characteristic resonant frequencies. If you add dampening, on the other hand, you tend to broaden those resonances (in frequency), and also to increase the decay rate of the sound, which is more rapidly converted into heat.

For example, steel has a lot of mass but affords little in the way of damping. Foam insulation offers a lot of damping but has little mass.  Heavy rubber has both high mass and high damping.  Stiff carbon fibers have little mass and little damping.

Rapid damping of the sound of a plucked string often occurs when the string vibrational frequency happens to be shared with one or more resonant frequencies of the instrument.  In such a situation, the vibrational energy of the steel string -- which has mass, but is highly elastic, with comparatively little intrinsic damping at all! -- is transferred quickly to drive both wood and air resonances. And THESE things are where all the real damping resides.  So the sound goes away sooner. And, of course, the energy that gets radiated away as sound production results in a damping (diminution) of the string vibrational energy.

So, it's not mass that dampens.  In fact, adding pure mass in the form of a heavy neck, a metal nut, and a metal bridge adds additional _sustain_ -- not damping! -- to instruments like a steel guitar.

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hank, 

Tom Haywood

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## hank

If you again consider how the simpler vibrational circuit of a tuning fork is managed you see similarities that might be helpful in wood and steel circuit couplings. Though very different than our stringed instruments vibration circuit some of the same mechanics can be easily observed. The more elastic smaller diameter and mass of the prongs are put in motion by taping either of the two. The vibration energy travels into the handle and to the opposite prong that turns the energy into sympathetic movement coupled to the still moving sister prong. Since there are two opposite points the elastic nature of the prongs and the coupling effect they have on each other is more visible than say the interplay of vibration in a bell shaped circuit with it's circular elastic rim. The stiffer higher mass of the tuning fork handle and the thicker more massive bell body is not elastic enough to move so easily in sypathy with the initial high amplitude pulse. The pulse becomes more powerful in its potential and is stored for a longer duration from this conversion in amplitude because more energy of the pulse is retained through the lowered resistance in the thicker more massive part of the circuit. This managed interplay between mass, elasticity and resistance(damping)can be manipulated in more complex systems involving the transmission of energy through different materials. 

What do tuning forks and bells have to do with building a stringed instrument? For simplicity and convenience let's find roughly the equivalent in it's components. That nice thick and dense stick attached to our highly elastic under tension gut,nylon and metal strings serves as a handle and adjustable tensioner support for the strings that provide the initial high amplitude vibration energy. The termination of the string at the nut is made very similar to each fret node along it's length in it's transmission of energy into the thick handle. If stopping the energy transfer was desirable all these connections would be dampened behind the hard nodal point. Of course they are not. The energy in the neck is now coupled to the opposite end of the string. As the vibrations at this opposite end are managed through the bridge to focus the pulse downward with not only low impedance but the addition of mechanical leverage(break angle). This mechanical leverage is used with the downward force of the tensioned string to boost the effect of the strings pulse causing a bigger effect on the movement of the top plates springy resistance. The plates thin recurve adjacent to it's outer rim attachment acts like a diaphragm springing back to it's original shape in the cycles between pulses thus coupling the pulses with the air around it. 
On the opposite end of the string the same pulse is being transmitted thru the nut and frets into the higher mass lower impedance handle and eventually the air coupling enclosure. From the view point of what is seen, the handle is obviously a structural part of the string tensioning device and with fingers an incremental string length and frequency changer. Your hand doesn't dampen the handles vibrations in a similar fashion as the tuning fork handle with it's low amplitude configuration. If frets aren't used the greater driving force of a bow is require to overcome the damping of your fingers against the string. If the vibrations available at the nut/fret/fingerboard,etc are dampened on the string side it obviously robs energy from it's osolations but energy is also robbed from the whole vibrational circuit if it is dampened in the neck and body connections. Damping of one part of the circuit because it is coupled together reduces effectiveness of the input energy and the instruments ability to hold that energy in a sustaining way. Of course this simplified attempt to explain this phenomena leaves out the devil in the details of how to manipulate your components to couple together in a positive way that doesn't cause null points and unwanted harmonic vibrations but it does point to a more holistic approach.

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Tom Haywood

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## Tom Haywood

Glad to see the effort to describe the physics in wholistic terms. Experience shows me that there is a clear audible difference in the sound of instruments having different pieces of wood for the neck, whether that is different species, different representatives of the same species, or different thicknesses of the same pieces of wood. It is difficult for me to describe the difference in terms of volume and tone, but there is a noticeable difference in the feel of the vibration in the neck - especially as wood is removed from a thick neck, which translates into a noticeable perception of "better" or "worse" sound in the overall instrument. One reason I play a new instrument in the white for several months is to slowly remove wood from the neck to achieve a balance of feel with overall improved sound of the instrument. The best description I've read of why this can occur is in a more poetic language. It is the idea that the vibrations, and therefore the sound, flow like various water currents in a stream. One can create better harmonization of the different currents by removing the impediments. The fundamental nature of the stream is not changed in any measurable way by removing some rocks, but the change in flow creates a local change in sound that can be readily perceived. Human perception involves judgment. In some spiritual traditions it is taught that harmony and beauty are intrinsically connected, and that we have evolved in a way to perceive very subtle variations in whether things are "in harmony". The greater the harmony, the greater the beauty that we perceive in it. Around 2,500 years ago, Pythagoras attempted to create a mathematics to describe this phenomenon in the physical world using the motion of the planets. Physics still has a ways to go, but it is clear to me that removing the obstacles that prevent all the parts of a mandolin from vibrating 'in harmony" results in a "better" or more beautiful sound that is clearly perceptible if not describable. From the modern physics standpoint, if we consider that everything in this universe down to the smallest piece of every atom is vibrating, then we are attempting to manage vibration. It is as much an art and a spiritual practice as it is a science, perhaps more.

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hank

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## hank

Simply put, the smaller you wish to make the neck profile, the more important it would be to use a denser neck blank, fretboard and fretboard extender. Extra material could be used in the extender to support a abrivated finger rest,etc..  By the same assumptions thicker necks wouldn't be as touchy if they have enough mass to keep the amplitude short in a more minimalistic approach using lighter materials.  Unfortunately my assumptions may not be helpful if something else I'm not aware of is the cause of unwanted damping on small profile necks like truss rod loading or movement, etc..

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## theCOOP

Sorry about the "mass dampened" comments. Perhaps my current car has, but certainly older car, namely Neon, has what the parts manuals referred to as mass-dampeners - large cast iron, aluminum and lead bits that helped to reduce NVH (noise, vibration and harshness).

The front lower motor mount connecting the engine to the rad support had an accompanying piece of cast iron bolted on with it to absorb vibration. The attic bucket of the centre console on some had a large aluminum casting around it, out of sight and behind the airbag was a large horse shoe shaped chunk of lead boltdd against the steering wheel to absorb vibrations. And then there's the harmonic balancer...

I was viewing the neck under the same principals.

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hank

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## Bertram Henze

> Perhaps my current car has, but certainly older car, namely Neon, has what the parts manuals referred to as mass-dampeners - large cast iron, aluminum and lead bits that helped to reduce NVH (noise, vibration and harshness).


That manual is using misleading language; like sblock said, masses don't dampen (i.e. they don't turn mechanical motion into heat), they just shift resonance frequencies - ideally to where they don't hurt, so the perceptible effect may resemble dampening without actually being it.

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hank

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## des

> .....  If frets aren't used the greater driving force of a bow is require to overcome the damping of your fingers against the string. If the vibrations available at the nut/fret/fingerboard,etc are dampened on the string side it obviously robs energy from it's osolations but energy is also robbed from the whole vibrational circuit if it is dampened in the neck and body connections. ............


Forgive me for coming at this from a different direction, but the biggest contribution to tone quality that I associate with the neck is the difference between the sound of an open string and a fretted one or indeed the even greater difference between a fretted and unfretted fingerboard/fretboard.

So I've wondered how a really hard fretboard - a material like toughened glass for example - would work in compensating the damping effect of the fingers. Has this been tried ?

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hank

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## Bertram Henze

> So I've wondered how a really hard fretboard - a material like toughened glass for example - would work in compensating the damping effect of the fingers.


Damping represents an energy leak. Soft material is a big leak, hard material is a small leak. Making the hard material harder means making the much smaller leak smaller and will not compensate for the bigger leak that's left unchanged.
Analogy: If you wade through deep mud, getting tired, what would you do for ease of walking: look for a drier and harder road, or wear harder shoes?

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hank

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## theCOOP

> Damping represents an energy leak. Soft material is a big leak, hard material is a small leak. Making the hard material harder means making the much smaller leak smaller and will not compensate for the bigger leak that's left unchanged.
> Analogy: If you wade through deep mud, getting tired, what would you do for ease of walking: look for a drier and harder road, or wear harder shoes?


I can't think of any benefit to harder shoes. 

Otherwise, how deep is the mud? Is the goal to "wade through mud"? I've actually had a similar conversation before. How dry does mud have to get before it's not mud anymore? 

Dryer and harder? It is certainly easier to WADE THROUGH mud than it is to WADE THROUGH dry, hard packed earth.

Perhaps I misunderstood :/

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## Bertram Henze

> Perhaps I misunderstood :/


Explaining analogies destroys all the fun, but here goes:

The mud are the hands (soft), the shoes are the fretboard (hard), the person trying to walk is the vibration. If you have hard hands (e.g. if you are a robot), that would be the dry, hard road (to walk on, of course, no wading required). A harder fretboard in soft hands would be just harder shoes on soft mud.

But hey, we are talking about the neck here, whose contact with human body parts plays a very minor role, compared to the back of the instrument body, for instance, where a tone guard makes a difference. I hardly think a tone guard for the neck would change much.

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## Ivan Kelsall

The instrument in which i feel 'neck vibrations' in most of all is my banjo. I feel virtually none in my Elec.guitar,a slight vibration in my mandolion necks,but the banjo neck really 'moves'. I think that this is mostly due to the relatively flexible neck to body (pot) joint.
When i play my banjo it feels 'alive' in a quite remarkable way,as though it's really 'trying' to sound good. It feels like a 'joint enterprise' when playing it. Whether that neck 'movement' adds anything to the actual tone,i don't know,if it does,i'd expect the resonance to be sub-sonic anyway,
                                               Ivan :Wink:

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## lowtone2

> Forgive me for coming at this from a different direction, but the biggest contribution to tone quality that I associate with the neck is the difference between the sound of an open string and a fretted one or indeed the even greater difference between a fretted and unfretted fingerboard/fretboard.
> 
> So I've wondered how a really hard fretboard - a material like toughened glass for example - would work in compensating the damping effect of the fingers. *Has this been tried* ?


 By bass players, yes. Jaco Pastorius was probably first to use a very hard finish on a fretless fingerboard, and yes that is a very different sound from an unfinished ebony or rosewood board. The fretted Rickenbacker basses of the 60s also had an epoxied fretboard, and that is thought to be a large contribution to the characteristic clanky sound of those instruments, even though they are fretted. Mandolinists, I don't know, probably an entirely different mechanism? Solid electric vs carved top acoustic. 

 I'm no builder, but this has been an interesting thread, for sure. I'm astounded by the luthiers who post here.

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