# Instruments and Equipment > Builders and Repair >  Further Adventures of Low Mass Bigfoot Bridge

## High Lonesome Valley

Addressing better weight distribution on my flat top Hora OM, I built a Bigfoot bridge out of western red cedar with a mahogany string slot overlay that worked okay and successfully precluded caving.  I had tried monolithic mahogany throughout, but this was too dense.  

So I considered the common practice of drilling of holes in bridges to reduce mass and came up with another approach of reducing mass that worked so well on the OM that the sound and volume actually exceed the original bridge I had to replace, really bringing out the voice and volume, while still maintaining lateral load integrity.  I overdid the length on the first bridge, only had to add 1.8cm over the original 10cm bridge length, but overall a lot more square mm on feet from original banjo bridge (which had three feet).

I again took western red cedar guitar top wood, glued a three ply for the feet, but left the middle ply out in the middle portion under the strings/arch.  The two outside plys are higher than the inside ply, and this creates a slot with a small portion over the foot itself as the support for the saddle.  In the slot placed a removable mahogany bridge saddle.  Just in the middle of the slot hollow portion, I glued a matchstick-size piece of cedar as a small third middle ply, flush to the saddle bottom, to prevent saddle collapse and slot widening.  I also find that having glued plys on either side of the slot, as opposed to a monolithic piece of wood, prevents splitting of the raised slot wood on either side of the saddle.

Now I have an extremely low mass bridge with a removable saddle, I can change the saddle material to tweak it even more.  

Essentially, the saddle rests on the feet, the raised sides of slot in the middle portion just holding the saddle in place laterally rather than horizontally.  The middle portion is hollow where the middle ply would have been.  Less mass, actually less contact of the saddle to the bridge.  More or less a truly floating saddle.

I formed an ellipse profile looking down from the top along the length of the bridge, with squared ends, to further reduce mass but still maintain integrity of slotted portion.  Looks kind of like a battleship with square ends.

So basically I found a way to essentially suspend a bridge saddle on a small portion of the feet.  The bridge saddle, a hardwood, is tall enough to prevent bowing in under the strings, especially with the pin glued to the middle of the adjacent slot plies.

The original Bigfoot was a square, 13 cm long and 1 cm wide on the feet.

Measurements:

3-to-2 ply western red cedar 33mm thick top wood.  Orientation of grain horizontal.

11.8cm long

60mm wide and 40mm tall at end of feet

1cm wide and 1cm tall at middle.saddle portion.  

Elliptical shape overall.  

Concave profile from saddle portion to end of feet.

At assembly, middle ply foot-60mm tall, outer plys 1cm tall

Foot length 3.4cm each foot (triple ply)

Middle ply 3.4cm long and 50mm tall outside feet only, outer ply 11.8cm long and 80mm tall full length.

Double ply hollow middle length (under strings) 5cm (50mm triple ply on either side to rest saddle on), arch 5cm long and 30mm high, small pin to bottom of bridge saddle glued in middle hollow portion

Slot and saddle length 6cm, total 2 ply-with-hollow-middle portion 5cm

Total slot length 6cm, width 30mm, compensated.

String/saddle height: 1cm treble, 1.2cm bass

Rough math on reduction of mass if 3 ply and square: Maybe 25%

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## Marty Jacobson

So this "bridge" is not really just a bridge, it's a bridge/external transverse brace. At least that's what I'm visualizing without being able to see it. So your conclusions really only applies to underbuilt / over-strung instruments, correct?

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## High Lonesome Valley

I guess it's a laterally braced support for the saddle, which rests on the feet only.   I think that bridges are only external pressure fixed braces anyway.  I also guess if you wanted to you could simply glue the saddle in place, but why.  I'm thinking of a mostly w.r. cedar saddle with a thin overlay of hardwood, see what that would do.

My conclusion, reduction of mass, applies to all acoustic instruments.  Reduction of mass increases transference of vibration,versus dampening.  In this case, it's great for my underbuilt overstrung instrument, effectively turning it into a well built properly properly strung instrument that may perhaps outshine much more expensive instruments.  I wonder how much the little contact of the saddle to the feet increases tone and volume.  So much depends on the bridge, as I'm sure you'll come to learn in time.

Not that this can't be overdone.  Violin bridges, as a point, are built to reduce certain unwanted overtones in the mid/high range and to promote clarity of upper ranges,and so maple is the preferred hardwood for violin bridges.

I appreciate your striving to understand the technical aspects of creative luthiery which can sometimes be a mystery to the uninitiated.  With an inquisitive and open mind, you'll find that there's a solution for almost any problem.

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## billhay4

I'd like to see a picture.
Bill

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## multidon

First of all let me state for the record that I am not a builder. I have built a few kits and done a few restorations. Strictly as a hobby. Because I have an interest in the subject of instrument building. I have been interested in the subject for some years now and through my self study and experiences I dare to say I have learned a thing or two. That being said there are world class builders on this forum who build very fine instruments. They comment often on many subjects here and those of us who are just hobbyists learn a lot from their kind and unselfish willingness to share knowledge. Marty Jacobson is one such builder. He is hardly "uninitiated". I found it interesting that every single one of those great professional builders, all of whom usually share opinions in a post like this one, stayed out of your first post on this subject altogether. To me that spoke volumes.

You, seemingly in a very unscientific way, take a single test case without taking any scientific measurements, at least none you shared with us, instead relying on anecdotal evidence like "really brings out the voice and volume". Your opinion only. Then you take that single test case and use it to make a broad sweeping generalization about all acoustic string instruments. I have to wonder why, if your conclusion is so obvious and your bridge design such a big improvement, why aren't all the instrument companies getting on the band wagon and changing their designs accordingly? 

I am sorry for my seeming inability to comprehend all of this. I suppose I must lack an "inquisitive and open mind".

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## billhay4

I don't think the OP stated that Marty is "uninitiated". Rather, he thanked Marty for taking an interest in this project. No need to start a fight here over that.
Sure, we need a bit more information, but that can be sought non-confrontationally.
Bill

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## Earl

From all I have gleaned, both from this forum and other sources, it seems that people have widely varied experiences (& theories) regarding bridge design & construction.  When I built my first instruments just a relatively short time ago, I read Red Henry's ideas about bridges: basically utilize lower mass materials & designs.  His arguments seemed compelling to me so I built my first bridges according to those principles.  I happened to run into a well-known builder just after I had finished my second OM.  He commented, & I agreed, that the sound was rather thin & suggested that I try a massive ebony bridge instead of the maple one with holes.  I took his advice & the sound was much richer & cleaner (IMHO).  Since then I have used relatively massive 2-footed 1-piece bridges & like the result.  I don't know, however, how much the result is due to the combination of all the other factors of design & execution.  It seems that people's experiences & opinions vary greatly on the topic of bridge design.

Interestingly, I think (IIRC) the only OM I have built that still has a low mass bridge is the one My nephew plays in the youtube clip I linked in the thread "OM #3".  One comment on that clip was that it sounded somewhat like "a banjo with a nice sustain".  That's the thin sound I mentioned above.  I hope I will be able to try another bridge on that instrument in the near future.  Here's the link again:  https://www.youtube.com/watch?v=O1knqjRwYI4

I agree that a picture of the bridge you describe would be a great benefit.

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## Pete Jenner

> Addressing better weight distribution on my flat top Hora OM, I built a Bigfoot bridge out of western red cedar with a mahogany string slot overlay that worked okay and successfully precluded caving.  I had tried monolithic mahogany throughout, but this was too dense.  
> 
> So I considered the common practice of drilling of holes in bridges to reduce mass and came up with another approach of reducing mass that worked so well on the OM that the sound and volume actually exceed the original bridge I had to replace, really bringing out the voice and volume, while still maintaining lateral load integrity.  I overdid the length on the first bridge, only had to add 1.8cm over the original 10cm bridge length, but overall a lot more square mm on feet from original banjo bridge (which had three feet).
> 
> I again took western red cedar guitar top wood, glued a three ply for the feet, but left the middle ply out in the middle portion under the strings/arch.  The two outside plys are higher than the inside ply, and this creates a slot with a small portion over the foot itself as the support for the saddle.  In the slot placed a removable mahogany bridge saddle.  Just in the middle of the slot hollow portion, I glued a matchstick-size piece of cedar as a small third middle ply, flush to the saddle bottom, to prevent saddle collapse and slot widening.  I also find that having glued plys on either side of the slot, as opposed to a monolithic piece of wood, prevents splitting of the raised slot wood on either side of the saddle.
> 
> Now I have an extremely low mass bridge with a removable saddle, I can change the saddle material to tweak it even more.  
> 
> Essentially, the saddle rests on the feet, the raised sides of slot in the middle portion just holding the saddle in place laterally rather than horizontally.  The middle portion is hollow where the middle ply would have been.  Less mass, actually less contact of the saddle to the bridge.  More or less a truly floating saddle.
> ...



Mate, what the **** are you talking about.
Keep it simple please for the terminally stupid like me.
Have enough respect to post a picture at least.

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## multidon

"I appreciate your striving to understand the technical aspects of creative luthiery which can sometimes be a mystery to the uninitiated"

If he is not addressing Marty then who? At that point Marty was the only person to respond. The above quote comes off as condescending. There is just no getting around that.

So now I'm being accused of trying to "start a fight" and being confrontational? Absolutely nothing could be further from the truth. But I will say I call it as I see it. I have always been like that. The kid in the story who was the only who had the nerve to say the emperor has no clothes? That would have been me. Are we really supposed to swallow all this stuff at face value just because the OP says so? Now if John (Sunburst), Dale, Paul, et. al. would chime in and say "Why yes! Of course a bridge is merely an external pressure fixed brace!" then maybe... But that hasn't happened, has it?

Compared with the wonderful builders on this forum who give me advice when I'm in a bind my skills are mediocre at best. But even though their skills far surpass mine none of them have EVER talked down to me. Ever. In fact just the opposite. The best of them, and you all know who I'm talking about, have a heaping helping of humility. They give you a sense of feeling like we're all in this together and we're all still learning. A little humility and not taking ones self too seriously goes a long way towards helping our interactions with each other, on line or in person. I go out of my way not to ruffle any feathers or tick folks off. But these two different threads about the bridge on this Hora, I just can't take it anymore. Guess I should just use the Ignore tool.

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Michael Lewis, 

Michael Weaver, 

Mike Bunting, 

Randolph

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## dang

Uhhhhh, I'm with Don on this one.  And I don't think he was trying to start a fight but rather that he wanted to point out to the OP that Marty is an established luthier of some very fine instruments... 

This is obviously not a new topic, I know another one of our wonderful luthier members, Dave Cohen has posted his experiments on "thinning" a bridge and removing mass from a bridge.  See his comments in this thread.  I know he has a more extensive write up on this but I can't seem to find his Brekke bridge modification that he posted.


I know the OP stated in another thread he is having a "digital crisis" and can't post pictures, but I am afraid a picture of this mysterious bridge is the only thing that may save this thread from ending up in obscurity.

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## multidon

Ah yes I had forgotten about Dr. Cohen's posts. Thanks for the link! Now there is a real scientist who did experimentation on this topic and admits he still doesn't have all the answers! He did make some interesting observations though but he avoids making a sweeping generalization based on the experiments. It would seem that based on what he found out so far that while a less dense bridge often results in more volume on a plucked string instrument, players often prefer the quality of the tone with a more dense bridge.

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## mandobassman

I also agree with Don.  You should certainly check who you're making condescending comments about before you do so.  Marty is one of the most respected luthiers on this Forum. Plus he doesn't just make Loar clones. He has experimented with different designs and really knows what he is doing.

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## High Lonesome Valley

> So your conclusions really only applies to underbuilt / over-strung instruments, correct?





> You should certainly check who you're making condescending comments about before you do so.  Marty is one of the most respected luthiers on this Forum.


It's called "payment in kind".

I'll try to get pics, I've had a digital meltdown of equipment recently.

Simply put, I have a Hora OM flat top without profiled bracing, truly flat.  I put J80's on it, making it sound great, but also creating an issue with dimpling under the bridge feet, a preview of caving.  Rather than simply going back to lighter strings, I approached the issue as to viewing the bridge as an external brace to more widely distribute the psi of the stings, just like an internal brace does.  

I also addressed this from the aspect of caving in in general, which happens to some fine and valuable bouzoukis and irish long scale mandolins. 

A hardwood bridge with these bigger feet killed the sound.  I used low mass western red cedar, which is also additionally pretty rigid, for a retro bridge.  More mass more so reduces transmission of vibration than less mass 

Essentially, a removable hardwood saddle rests on two wr cedar feet, nothing underneath most of the saddle except two lateral pieces alongside of wr cedar that continue from the feet.  The feet are three ply, the saddle portion is two ply missing the middle ply, saddle resting just on the edge of the middle ply of the feet.

Marty and others seemingly have an issue with those of us who can't or won't afford a $1200 instrument, hence his cryptic comment reflecting his other past derogatory observations.  What he missed is that 1.  Low mass is better in cases like the Hora and 2.  This is a possible fix for some really great instruments that are experiencing caving, a fix that will less compromise the overall sound of the instrument.

A forum-respected luthier doesn't like an idea he's never considered and reasserts his own condescending paradigm.  I can respect that.

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## dang

I know you can't post a picture of this "fix" right now and without any audio files of this instrument before and after this modification we will have to take your word for it.  

Since you joined the cafe this month forgive me if I don't take your word for it.

I doubt you are building any trust in this community by responding in such a way to a legitimate question.  If it wasn't either under built or overstrung why would the top be caving in?

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## billhay4

Multidon,
Looks like I was wrong. Please excuse me.
Bill

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## Dave Cohen

> I guess it's a laterally braced support for the saddle, which rests on the feet only.   I think that bridges are only external pressure fixed braces anyway.  I also guess if you wanted to you could simply glue the saddle in place, but why.  I'm thinking of a mostly w.r. cedar saddle with a thin overlay of hardwood, see what that would do.
> 
> My conclusion, reduction of mass, applies to all acoustic instruments.  Reduction of mass increases transference of vibration,versus dampening.  In this case, it's great for my underbuilt overstrung instrument, effectively turning it into a well built properly properly strung instrument that may perhaps outshine much more expensive instruments.  I wonder how much the little contact of the saddle to the feet increases tone and volume.  So much depends on the bridge, as I'm sure you'll come to learn in time.
> 
> Not that this can't be overdone.  Violin bridges, as a point, are built to reduce certain unwanted overtones in the mid/high range and to promote clarity of upper ranges,and so maple is the preferred hardwood for violin bridges.


That's a lot of certainty re things about which no one else has been that certain.  I'll limit my repsonse to pointing out some things for your consideration.  First and foremost is that there is no transference of vibration from strings through bridge to top plate.  The vibrational motions of strings are normal modes of strings, and are characteristic only of strings.  The vibrational motions of top and back plates are normal modes of those plates and are characteristic of those plates only.  So the take-home is that string vibrations stay in strings and plate vibrations stay in plates.

I've posted this several times before.  When strings vibrate, they exert pulses of force on the bridge each time the antinodes pass through zero amplitude.  Those pulses of _force_ are transferred to the top plate through the bridge, and excite the normal modes of the top plate, which in turn,...., well it goes on from there.  As for "dampening", I think you mean _damping_.  Strings lose energy as a result of the motion they induce in the plates.  The plates in turn lose energy to several sinks.  One of those sinks is the air that the plates set in motion.  But the biggest source of actual damping is the internal losses in the materials themselves.

The impedances of each part of an instrument are frequency-dependent.  They are kind of like resistances to that part being set in motion.  At low frequencies, a little extra mass is not too much of a problem.  At higher frequencies, extra mass is harder for the higher modes of motion to move.

It occurred to me that western red cedar is pretty soft.  I would worry about w.r. cedar in a bridge being crushed over time by the down forces from the strings.  Maybe even mahogany.  I have had to replace more than one ebony bridge saddle that has cracked - on my own instruments, and on others (including those of major manufacturers) as well.  And, I have seen a lot of ebony mandolin bridge saddles actually sagging to the extent of being visibly bowed.  Something for you to consider.

http://www.Cohenmando.com/

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## High Lonesome Valley

> If it wasn't either under built or overstrung why would the top be caving in?


It's now neither thanks to American ingenuity, that's the whole point of this bridge exercise.

Don't take my word for it, that's why I included measurements and concepts, so you could try this yourself.  If you have a caving top, consider a bigger footed bridge as an alternative to lighter strings.  If hardwood kills the sound, try a rigid lower mass wood, and here's a cool way to reduce the amount of wood in the bridge altogether.  That's all I've been trying to share here.

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## High Lonesome Valley

> First and foremost is that there is no transference of vibration from strings through bridge to top plate.  The vibrational motions of strings are normal modes of strings, and are characteristic only of strings.  The vibrational motions of top and back plates are normal modes of those plates and are characteristic of those plates only.  So the take-home is that string vibrations stay in strings and plate vibrations stay in plates.
> 
> I've posted this several times before.  When strings vibrate, they exert pulses of force on the bridge each time the antinodes pass through zero amplitude.  Those pulses of _force_ are transferred to the top plate through the bridge, and excite the normal modes of the top plate, which in turn,...., well it goes on from there.  As for "dampening", I think you mean _damping_.  Strings lose energy as a result of the motion they induce in the plates.  The plates in turn lose energy to several sinks.  One of those sinks is the air that the plates set in motion.  But the biggest source of actual damping is the internal losses in the materials themselves.
> 
> The impedances of each part of an instrument are frequency-dependent.  They are kind of like resistances to that part being set in motion.  At low frequencies, a little extra mass is not too much of a problem.  At higher frequencies, extra mass is harder for the higher modes of motion to move.
> 
> It occurred to me that western red cedar is pretty soft.  I would worry about w.r. cedar in a bridge being crushed over time by the down forces from the strings.  Maybe even mahogany.  I have had to replace more than one ebony bridge saddle that has cracked - on my own instruments, and on others (including those of major manufacturers) as well.  And, I have seen a lot of ebony mandolin bridge saddles actually sagging to the extent of being visibly bowed.  Something for you to consider.
> 
> http://www.Cohenmando.com/


Thanks Dave, I'm admittedly not a physicist, this is a great treatise that makes smoke come out of my ears to read.

Just posted pics, you'll see a piece of wood in the middle gap, flush to the bottom of the saddle, I glued in to stop sagging of the saddle itself, am considering posting one under each double string.  

The inside of the foot is a slight plane higher from horizontal, an inverse angle toward the middle, to compensate for the entire bridge slightly bowing, kind of a spring action that engages the entire surface of the foot when strung up.

I'll let you know if the bridge blows up under the stress, so far so good.  I think the little shelf on the foot will hold up, the issue will be the saddle I think.

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## Eric Foulke

I wish you had just posted these pictures in the first place. We could have avoided a lot of confusion. Based upon your description I had a totally different vision of what you were doing. This is in the same spirit as the Selmer bridges, the whole underside of the bridge is hollowed out to a thickness of about 3mm. The bridge weighs much less than it looks.




> That's all I've been trying to share here.


Unfortunately thats not all you have shared. I would be remiss in not addressing some of your other statements. Your description might have been very clear in your mind, but in the absence of pictures it is wrong to assume that everyone would understand exactly what you were doing. 
To "do" anything, whether it be "new" or not, is to risk being questioned, especially on the internet. You cannot control the question or the intent behind it, all you can control is how you respond. In my opinion you responded poorly- you jumped to a lot of conclusions as to the intent of Marty's original question. Your comments were rude, condescending and completely unnecessary. 

Luthierie should be a joy, let's try to keep it that way.

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## High Lonesome Valley

> I wish you had just posted these pictures in the first place. We could have avoided a lot of confusion. Based upon your description I had a totally different vision of what you were doing. This is in the same spirit as the Selmer bridges, the whole underside of the bridge is hollowed out to a thickness of about 3mm. The bridge weighs much less than it looks.


If you mean the jazz guitar floating bridge, this is a bit different, it's not hollowed out, there is no bridge support under most of the removable saddle, just a bit of support where the saddle hits the feet and the chunk in the middle.  More like a floating saddle than a monolithic hollow bridge.  

Hope to put some more mileage on this idea, have the wood, glue, and the time.

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## Eric C.

> It's called "payment in kind".
> 
> 
> Marty and others seemingly have an issue with those of us who can't or won't afford a $1200 instrument, hence his cryptic comment reflecting his other past derogatory observations.


This is.... the most inaccurate statement I believe I've ever seen on this forum. Marty went out of his way and _designed_ methods of construction to produce very wonderful instruments for those that can't (or will never be able to) afford high quality, custom built mandolins. While (understandably) they are not $1200, they are well below $2000. Marty is genuinely a great guy that cares for his work and treating his customers fairly. To call his questions derogatory is an insult to him, and to this community as a whole.

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billhay4, 

Charles E., 

Mike Bunting, 

Pete Jenner

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## Bernie Daniel

> It's now neither thanks to American ingenuity, that's the whole point of this bridge exercise.
> 
> Don't take my word for it, that's why I included measurements and concepts, so you could try this yourself.  If you have a caving top, consider a bigger footed bridge as an alternative to lighter strings.  If hardwood kills the sound, try a rigid lower mass wood, and here's a cool way to reduce the amount of wood in the bridge altogether.  That's all I've been trying to share here.


Perhaps, as you become better aware of this forum, you will realize that the Mandolin Cafe is almost certainly the world center of mandolin information and history.  I have said this before but I'll say it again -- if there is a mandolin question that cannot be answered by the members of this forum then the only reason is the question has not been asked yet!

You will also learn that almost NOTHING you do in the way of innovation will REALLY be new. 

Almost EVERYTHING has been tried before including your ideas on that bridge.  That is not to take away from your thinking it up or for trying it -- but its been done before.  

I build a very similar bridge a few years ago for a mandocello I was working on.  The only difference was I used rosewood for the base and bone for the saddle!  I am sure I was not the only one either!    :Smile: 

BYW I also tried red cedar, and also fir, for a bridge once to get less weight but I felt the sound  was "mushy" and muted compared to rosewood.

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## stevedenver

wow 
looks similar in concept to what jimmy D aquisto did for his later archtop guitar bridges with the sliding bit, very cool!!

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## Bernie Daniel

> wow 
> looks similar in concept to what jimmy D aquisto did for his later archtop guitar bridges with the sliding bit, very cool!!


Yes, you are probably taking about this one? I built several like this to try on a Gibson mandocello with top sag.

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## stevedenver

Bernie-that's beautiful work indeed

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## Michael Weaver

Marty Jacobson, though an underachiever in many aspects, is still striving to understand the technical aspects of creative luthiery which can sometimes be a mystery to the uninitiated. With an inquisitive and open mind, you'll find that there's a solution for almost any problem.  Like maybe the solution to a sagging bridge? I bet Marty wishes he could come up with such an idea.  
 

 

Or maybe even a solution to clamping an armrest to the top and back of a mandolin.....dare I say..a free floating armrest!!! Whoa I bet Marty wishes he could think of something like that!!  

 

Oh wait....is that also a tailpiece he designed and made by himself? No way......not in this lifetime. Poor Marty will never be successful with these amazing designs out on the market.   

Before you decide to rip apart an innovative luthier you need to think about it for a second. 1) Marty would have accepted a call from you and probably would have even helped you design a bridge. 2) You might want to study another persons work before flattering yourself with your amazing innovations. 3) if you read Marty's question, it's actually a question not a statement. Meaning he wasn't being confrontational. 4) let us know when it hits the market, Orville.

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LongBlackVeil, 

Mike Bunting, 

Pete Jenner

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## Bill Snyder

High Lonesome, I hope you are not getting the feeling that the Mandolin Cafe is not a hospitable place. It is generally very welcoming to newcomers and to a large degree to new ideas. However as you have seen, newcomers that come in here with an "I know more than you" attitude and refuse to respect some of the experienced and very helpful existing members are going to be put in their place.
Don't take anyone's remarks as an invitation to leave or to quit contributing. Instead take them for guidance on how to share ideas and knowledge without slamming someone else.

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Michael Weaver

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## Bernie Daniel

> Bernie-that's beautiful work indeed


Yes it is Steve!  That image appeared a guitar forum about 7-8 years ago!  :Smile:   I save it because it looked so cool.   The great James D'Aquisto built that all-ebony bridge.  It adjusts by sliding a wedge shaped ebony bar between the base and the saddle he wanted to eliminate thumb screws but still have a variable height bridge.  So in this bridge only wood is transmitting the energy from the strings to the top.  On the same thread as I recall there were some who claimed this idea was not a good one for getting the sound out of the guitar nonetheless it is certainly a beautiful thing to look at.  Maybe John Monteleone tried this idea too?

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## billhay4

HLV,
I see nothing remarkable or particularly innovative about this bridge, but I do see one glaring problem -- the single support under the saddle. This means the saddle will rock under the pulses of force exerted by the vibrating strings. This will lessen the effect of this force, I think, as well as introduce irregularity into the force system.
If I'm wrong on this, don't excoriate me. I'm not calling your creds or manhood into question; just the value of this one bridge you've constructed. And I'm willing to listen to any reasons I might be wrong here.
Bill

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## High Lonesome Valley

> HLV,
> I see nothing remarkable or particularly innovative about this bridge, but I do see one glaring problem -- the single support under the saddle. This means the saddle will rock under the pulses of force exerted by the vibrating strings. This will lessen the effect of this force, I think, as well as introduce irregularity into the force system.
> If I'm wrong on this, don't excoriate me. I'm not calling your creds or manhood into question; just the value of this one bridge you've constructed. And I'm willing to listen to any reasons I might be wrong here.
> Bill


I wear a kilt, manhood intact :Grin: 

Thanks for the tip.  I'll try one without that middle support.  I can just profile the top of the saddle to adjust for any bowing, maybe even go elliptical on the saddle itself.  I'll let you know how it turns out.

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## billhay4

I went back and looked at the photos again, but still can't see. What does the saddle rest on exactly? I had interpreted the photos as showing it rested solely on the middle support, but your response seems to suggest otherwise. If the saddle is supported all along the base, my comment is probably incorrect. What I had envisioned is a sawing motion as the bass and treble strings were struck alternately and all the motion focused on the middle support. That would not be good I don't think. If the saddle is supported all the way across, it would act just like a normal saddle.
Bill

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## Dale Ludewig

Slightly off topic, but I can't help myself.  Most people with credibility or responsibility for their opinions on this forum use their real name when posting.

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Bernie Daniel, 

Michael Lewis, 

Mike Bunting, 

Pete Jenner

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## Bill Snyder

> Slightly off topic, but I can't help myself.  Most people with credibility or responsibility for their opinions on this forum use their real name when posting.


And before anyone points to sunburst he makes no secret as to his real identity even putting his name and website at the bottom of every post.

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## Dale Ludewig

Bill, no worry on my end, of course.  Everyone knows who sunburst is or ought to.  As you said, it's clear from his signature.  My comment was directed elsewhere.  I just think that this is a special place on the web, a place where we should act like we're sitting in a big room talking to each other, perhaps having a conversation in public that other people might be interested in.  And as such, each person involved should have no fear about asking a question or expressing an opinion when done openly and honestly, or perhaps even in sport.  Not hiding behind some "screen name".

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Bob Clark

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## Pete Jenner

Yes - sorry about that. One day I will reveal my real name but for the moment, in the interests of international security,  I would appreciate it if you keep referring to me as 'Great One'. 'Oh Great One' is fine too. ...or OGO for short.

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## Bill Snyder

Dale, I was just trying to do a preemptive strike should someone else use John as an example.

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## Rick Lindstrom

This is an entertaining thread. 

I looked at the photos, and the saddle part of that bridge appears to be supported at both ends and in the middle. It _is_ unconventional, and I imagine it works just fine.

Bill didn't use one like that, but what are you gonna do?

My name is 

Rick

----------


## Jeff Mando

> Yes - sorry about that. One day I will reveal my real name but for the moment, in the interests of international security,  I would appreciate it if you keep referring to me as 'Great One'. 'Oh Great One' is fine too. ...or OGO for short.


OK, me, too.  Ya got me.  My real name is Elton John.  If you need mandolin tabs for Candle in the Wind or Philadelphia Freedom, just let me know.....

----------


## stevedenver

I too understood that Jimmy DAquistos thinking on an all wood adjustable bridge was to avoid metal as a conductor.  It reminds me of the recent simonff article on low mass, all wood violin style bridges for mandolins.  I assume the sound (string) transmittal would be the same, only......adjustable. 

As for sound, I guess it would depend on the voice of the instrument.  I have heard, but don't necessarily concur, that martin folks say a rosewood bridge acts as a different frequency 'pass' than does ebony.  Ditto bone, walrus or fossiliezed ivoryetc for saddles, pins etc, some of which I do hear.  

Obvioulsy we have seen (and heard) mandos of good breeding with aluminum, or, ivory or bone inlay atop the bridge as a partial saddle to brighten the top courses, etc.

Likewise, on archtop guitars, it is reputed that a wooden tailpiece will impart a more woody less metallic tone than a metal tailpiece.  I can vouch for this, based upon my own ears and trading out a D'A styled tailpiece for a Benny wooden one. Don't ask me why this matters, since it behind the bridge and fully floating, but by Gawd, it does.

If one were to use the broader width base, as D'A did-(some of his are about twice the 'normal' width of a bridge foot, as that pic shows with closer inspection), as well as well seated parts or, even parts with an interlocking groove or route, I see no reason that this bridge would be any more subject to leaning than, say, a narrow loar type.

what say ye all to the idea of a broad foot for a mando bridge-I know this has been used much more frequently recently , and I recall some old Gibson guitars having asymmetrical and broad bridges in the 80s, which looked odd but were supposedly a more balanced 'transducer'.

----------


## Stephen Perry

i did not see the simonoff article.  where might i find it?

thanks

----------


## stevedenver

> i did not see the simonoff article.  where might i find it?
> 
> thanks


I just briefly perused the Siminoff  in an effort to find you a link and wasn't able to locate it, but I read it on this forum, about a month or two back.  

It was about drilling out bridges and the positioning of the feet in relation to the bridge scrolls for maximum strength and direct transmission.  It also mention how the scroll and feet interacted to act as 'filters' for certain frequencies-(fwiw I _thought_ it was authored by Siminoff.) 


Perhaps it was from Frets or some other publication.  Hopefully, someone else will be able to provide a link.

----------


## Bill Snyder

Stevedenver, HERE is an article by Frank Ford on building a light weight mandolin bridge.

----------

stevedenver

----------


## Stephen Perry

I am very interested in this general subject and welcome - beg for - additional input.

Readers here are likely familiar with my work on mandolin bridges. See, e.g., my mandovoodoo site for what I do.  Mostly.  There are other things, and I'm always learning stuff.  I'm working to get the two pieces of the bridge working well independently, then together, and then with the instrument. An iterative process.

On the violin side, I am working with the usual numerical parameters, then proceeding to adjust in a fairly typical manner.  

On both, I aim to reduce the "noise" introduced by the bridge itself and to get the clarity of the reproduced sound increased.  

Listeners and my clients - and me, too - notice especially the increased apparent projection of the lower notes on both instruments.  I can manipulate this more easily and effectively on violins.  I cannot increase the sound output at the low frequencies, but I can reduce "holes" in the response up the neck by manipulating various things.  On violin bridges, that manipulation is fairly easy (well, maybe not) through manipulation of the cutout size and shape and especially the kidney and heart "wings."  I do not have that control on a standard mandolin bridge, thus my interest in mandolin bridges with wings, and with indirect paths to the top.  

One useful thing to consider, in my view, is the role of the harmonics of the fundamental.  See here the harmonics of the G string on a violin: http://rceezwhatnext.blogspot.com/20...ectograms.html   The pretty square 3d chart down the page shows the important role of the harmonics.  That's what I'm working with in violin adjustment of the bridge, at least in part, and what I wish to further adjust on mandolins.

I welcome observations and feedback. If I come up with some ideas from the article mentioned above, from comments, and from other threads (pointing to those threads would be very helpful), then I will make some experimental bridges.

As an aside, I am now working in my shop with a new collaborator from the wind work, who I am training up in strings.  I am hoping she can learn the mandolin end of things so I am not as essential.  I have had difficulty recovering from an injury (vehicle crash in January) and need the extra hands, regardless.

Be well, thank you all for the observations above.  The more I learn, the less I know, and the less secure what I "know" becomes!

----------


## High Lonesome Valley

> I went back and looked at the photos again, but still can't see. What does the saddle rest on exactly? I had interpreted the photos as showing it rested solely on the middle support, but your response seems to suggest otherwise. If the saddle is supported all along the base, my comment is probably incorrect. What I had envisioned is a sawing motion as the bass and treble strings were struck alternately and all the motion focused on the middle support. That would not be good I don't think. If the saddle is supported all the way across, it would act just like a normal saddle.
> Bill


Bridge rests on 50mm slot on foot and the chunk in the middle, no movement when playing as I can tell do to the downward force.  Lateral or two continuance plies of wood to hold it laterally, but I think this more so holds the feet to the whole contraption.

BTW, Michael Weaver, that's a great looking bridge, but barely resembling the simple design I posted.  That is a high, as opposed to a low, mass bridge as well.  Feel free to read the OP to see why I am playing with low mass.  The more I play with the idea, the more I find out, and really haven't found much on the net or elsewhere regarding using spruce or wr cedar for mandolin or violin.  Most of the research is on hardwood bridges using mostly maple, rosewood, and ebony, some mahogany.  I'm not hitting any market soon, Michael.  I take it that was said tongue in cheek.

I guess the use of western red cedar for a bridge is pretty controversial, seems everyone's creative juices have been stirred.  A few folks have had there sensibilities offended and given a thumbs down outright.  Some have critically suggested improvements, which I plan on trying out.  That's one of the reasons I posted, and thank you.

----------


## multidon

I for one do not dismiss your choice of Western Red Cedar out of hand. It makes some sense if you are going for low mass. It is 30 percent lighter than mahogany and has a great strength to weight ratio. And of course it goes without saying you won't have a problem with moths in your case!

I am curious how it would do with a bone saddle in that slot.

----------


## billhay4

HLV,
The saddle (not the bridge) cannot rest *on* a slot, or at least that makes no sense to me as a slot is an empty space. If it rests in the slot, please clarify what it sits on besides the "chunk" in the middle. Does the saddle have a ledge that rests on the edge of the slot? or is there some other mechanism? If it rests SOLELY on the chunk in the middle, then my previous comments stand. The varying action of the strings as they are struck will be somewhat dissipated. What this means in terms of transferrence of energy to the top, I cannot say, but others more qualified than I can.
Bill

----------


## High Lonesome Valley

> HLV,
> The saddle (not the bridge) cannot rest *on* a slot, or at least that makes no sense to me as a slot is an empty space. If it rests in the slot, please clarify what it sits on besides the "chunk" in the middle. Does the saddle have a ledge that rests on the edge of the slot? or is there some other mechanism? If it rests SOLELY on the chunk in the middle, then my previous comments stand. The varying action of the strings as they are struck will be somewhat dissipated. What this means in terms of transferrence of energy to the top, I cannot say, but others more qualified than I can.
> Bill


There is a 50mm long slot, a squared U shape, on the edge of where the foot area begins, that would be the ledge.  This is the slotted portion of the supporting bridge, just over the feet alone.  The chunk in the middle was glued in for the top of the chunk to be flush with the bottom of the saddle,.  

So there are three small surfaces the bottom of the saddle rests on; the middle and both ends.  Most of the saddle is resting on nothing.  For the length of the saddle, there are two pieces of wr cedar running laterally which the chunk is glued to, but no wood underneath the saddle for most of it except for the small portions of the feet, as a ledge, and the chunk in the middle.

The portion of the feet slots take most of the weight.

Think of the saddle as a three footed bridge, with very small feet.

I wish I could do 3D CAD.  It would be a help.

----------

billhay4

----------


## High Lonesome Valley

> I am curious how it would do with a bone saddle in that slot.


Great idea.  As we collect dead wild horse parts from the surrounding mesas, no lack of material.

Edit 30 minutes later:  Bone saddle gives it a "punch", brought mids up overall, slight increase in overall volume and fixed the low G string weak sound.  Keeping the bone saddle versus mahogany.

Thanks, multidon, great improvement overall on sound.

----------


## stevedenver

> Stevedenver, HERE is an article by Frank Ford on building a light weight mandolin bridge.


Actually in looking at it, that isn't the same article I remember.  I read that one too, but the one I am thinking of, I thought was Siminoff, it was lengthy and had variations and results of bridge scrolls and sound.

----------


## Stephen Perry

is this it?

http://siminoff.net/blog/

----------


## Mike Bunting

oops

----------


## Mike Bunting

> Yes - sorry about that. One day I will reveal my real name but for the moment, in the interests of international security,  I would appreciate it if you keep referring to me as 'Great One'. 'Oh Great One' is fine too. ...or OGO for short.


Hey, you can't use that name! It was the name of the great Canadian hockey player, Wayne Gretzky.  :Smile:

----------


## Marty Jacobson

Mike, now you've blown his cover. Terrible.

----------

Pete Jenner

----------


## stevedenver

> is this it?
> 
> http://siminoff.net/blog/


why yes it is-!!!!

----------


## Pete Jenner

> Hey, you can't use that name! It was the name of the great Canadian hockey player, Wayne Gretzky.


Is that ice hockey or real hockey?

----------


## billhay4

> Hey, you can't use that name! It was the name of the great Canadian hockey player, Wayne Gretzky.
> Is that ice hockey or real hockey?


Yes.
Bill

----------


## Stephen Perry

> why yes it is-!!!!


Excellent.  Perhaps I'll have time to follow up relatively soon.  There are a variety of issues with the usual adjustable bridge as far as sound transmission and balance go.  A problem with mandolin bridges is their lowness!  Leaves fairly little material to work with.  However, I can likely come up with some concepts that would allow greater adjustment of subtle things.  Now, whether the mandolin will feel and hear the adjustments is another matter, but they are sensitive to minor things in a surprising way. I was certainly surprised by my early experiments, after attempting to debunk the Spears book oddness.  I only decided I wasn't hallucinating when Roscoe Morgan exclaimed "It's mandovoodoo" and I knew I was on to something.

Thank you all for your participation.  Any additional thoughts on mass, shape, whatever would be very gratefully absorbed.

----------


## rockies

There is also the "Brekke" bridge. The articles in the Mandolin Magazine by , I believe Bruce Weber back quite  few years ago were great reading as he tested against I believe a Monteleone designed solid bridge. I used one on my John Sullivan mandolin, but about once a year went back to the conventional adjustable bridge and then back to the Brekke and back and forth. Both bridges sounded different and I liked both sounds, but it was like having two slightly different mandolins. I also liked the adjustable wedge idea of the Brekke. Just my humble opinions. Maybe I should try one on my Heiden ??
Dave

----------


## Dave Cohen

> There are a variety of issues with the usual adjustable bridge as far as sound transmission and balance go.  A problem with mandolin bridges is their lowness!  Leaves fairly little material to work with.  However, I can likely come up with some concepts that would allow greater adjustment of subtle things.  Now, whether the mandolin will feel and hear the adjustments is another matter, but they are sensitive to minor things in a surprising way.
> 
> Thank you all for your participation.  Any additional thoughts on mass, shape, whatever would be very gratefully absorbed.


Issues with sound transmission??  Amazing, considering that there is no "sound transmission" from strings to bridge to top plate.  The string vibrations stay in the strings.  Each time the antinode(s) of the string mode(s) pass through zero amplitude, a normal force and a tangential force are exerted on the bridge.  Those dynamical forces excite the normal modes of motion of the (bridge + top plate).  The plate motions in turn exert forces that excite the normal modes of motion of the rest of the parts of the instrument, including the air in the body cavity.

I haven't read the Siminoff work referenced here, but I noted one ridiculous thing from it in a previous thread.  Apparently Siminoff claimed that there are diagonally oriented forces from the strings to the string posts.  That is just nonsense, from a knowledge of even freshman level physics.  The static force from a string is purely a down force coming from the string tension and the breakover angle.  Unless there is some sideways component of force, all of the force has to be downward.  It is exerted on the entire bridge saddle, which in turn exerts only the same down force on the top plate.  If anything, the configuration of the strings should exert a slight component of force _inward_ toward the center of the bridge saddle, but I would emphasize the _slight_.  As for the dynamic forces from the strings, the tangential force(s) are not sideways, but rather along the length of the string, and would induce longitudinal rocking motion(s) in the bridge.  The normal force(s) are again downward forces.

http://www.Cohenmando.com/

----------

Charles E.

----------


## Stephen Perry

1.  We'll stay with "seismic energy" instead of sound, although Dr. Cohen certainly understands what Dr. Perry is writing about and has probably had much more sleep. 

2.  I suspect the "diagonal" type thinking permeates much bridge conceptualization.  See, e.g., http://www.rivinus-instruments.com/bridge%20graphic.gif  -- which isn't at all how I tend to think of such things.  A violin bridge has these beautifully thought out arched structures all flowed together.  A shame to merely think of it as hosting these imaginary lines!  On the other hand, the black pendulum zones allow tuning.

3.  The longitudinal movements must indeed play a big role in getting seismic energy down to the sounding surfaces and back up (can't neglect the return signal).  

4.  I'm curious about whether something allowing more detailed tuning is feasible for a mandolin bridge.  The work of Tim van Dusen comes to mind.

Have fun!

----------


## Folkmusician.com

I should know better than to read this type of thread first thing in the morning.  :Coffee:

----------


## Stephen Perry

Likewise.

I'm curious about the effect of contact area and location with the top.  Violin bridges do their work through surprisingly little material and small contact area.  Of course, the inefficiency possibly introduced by having a rather live bridge may work with a continuous input but not with a plucked instrument!  The unifying waist seems pretty obvious.  But then, so do the tangs on van dusen's original bridges, and he's doing away with those in later models!!!

----------


## Stephen Perry

Ok Ok .    

Raw effect of mass

Raw effect of contact area

Raw effect of longitudinal coupling (hard to think of explaining - think of a very wide bridge as coupling better)

Raw effect of lateral coupling (making this up, overall span w/ same contact area)

Raw effect of relationship of contact area to tone bars

I can now "invent" about 200,000 bridges to make and test.  That's sort of the problem.

Oh yeah, material impact!!!!  Hmmm.  

Think I'll go back to simply thinking about how to add tunable pendulums so I can treat a mandolin bridge more like a violin bridge, rather than like two marimba bars.

Have fun!!!

S

----------


## Pete Jenner

> 1.  We'll stay with "seismic energy" instead of sound...


 That only works with rock music ...in acoustic music, your plates would have to be tectonic.

----------


## Dave Cohen

> 1.  We'll stay with "seismic energy" instead of sound, although Dr. Cohen certainly understands what Dr. Perry is writing about and has probably had much more sleep.


Do me a favor and don't make assumptions about me.  And with regard to seismic energy: What are you smoking?!

http://www,Cohenmando.com/

----------


## Stephen Perry

At least I don't lecture at the drop of a hat!

Seismic energy seems pretty fun term to me, but I'm a geologist, so it would!

I looked into a lot of bridges and don't see what I see violin bridges doing being echoed.  Not sure I can fit all that into a mando bridge, but I'll eventually try!

----------


## High Lonesome Valley

> That is just nonsense, from a knowledge of even freshman level physics.http://www.Cohenmando.com/


You hurt my brain.  I've been diagnosed with "dyscalculia", dyslexia with numbers, one of the reasons I love working on old instruments and old houses, they're more of a feel thang.  Only passed Algebra 101 cause I was nice to our rocket scientist instructor.

Measure twice, cut three times.

----------


## Dave Cohen

> You hurt my brain.  I've been diagnosed with "dyscalculia", dyslexia with numbers, one of the reasons I love working on old instruments and old houses, they're more of a feel thang.  Only passed Algebra 101 cause I was nice to our rocket scientist instructor.
> 
> Measure twice, cut three times.


I am not responsible for your brain ache, nor is my subject matter.  You will have to take responsibility for your own problems with things mathematical and empirical.  

Aside from your medically diagnosed problems. many people who steer away from things mathematical and scientific do so for a couple of common reasons.  One of those reasons is a low opinion of their own capabiities.  Another is a temperament lacking the patience to deal with abstractions and symbolic representations.  Mathematics and the physical sciences based in mathematics require the patience to stay with a problem until you get it.  That kind of thing does not come immediately to anyone.  Everyone who does those things has to put in the time.  No one who gives up easily will get there.

As for the "feel thang", I can only offer that music itself, let alone musical acoustics, is just filled with mathematics.  Doubtless you won't take my word for that, but if you were to take the time to look deeply into the matter, you would find it to be true.

Regarding Stephen's glib retort: Lecturing has been a significant part of my job description for all of my working life, and still is on occasion.  I love the subject matter, and so I have done the lecturing gladly.  Old habits die hard.  One thing I _don't_ do is sling baloney.

http://www.Cohenmando.com/

----------

Kennyz55, 

Pete Jenner

----------


## Keith Newell

I used to get so frustrated with Mr Cohen's posts. Then after a breath or two, a beer or two and re-re-re-read them He is a treasure to the community. I also played around with low mass bridges and have a thread on Reds site. No real scientific stats but when I build an octave it has a maple bridge. My preference, not stats...just me and a very quite shop and my choice. 
 Love the café and the wealth of knowledge. I've grown out of the stage where I took offenses to any questions. I know what I know and learn something every time I come here. You can only better your experience or product by reading and absorbing, then you can try stuff on your own and THEN relate it to what all these fantastic luthiers post on a daily basis.
Keith Newell

----------

High Lonesome Valley

----------


## Vincent Capostagno

I have a background in radiation physics and can conceptualize and quantitate chains of energy-matter interactions in three dimensions but I also get a little "headache" when I try to conceptualize mechanical-acoustic interactions.  Perhaps because of the new terminology and the unfamiliar formulations: but it doesn't surprise me that I have some difficulty understanding in 15 minutes what someone else spent over 15 hours to conceptualize and explain. Whether I understand it or not, I don't deny that the science exists.
I can understand that a highly intelligent, passionate music lover without such a background and facility might choose an alternate more intuitive/artistic pathway (or both) to achieve the outcome of their endevours but I don't think it is necessary to create a pseudoscience (eg. electrons jumping over interfaces of long grain, oxygen free copper in audio cables) in order to justify the validity of their work product.

----------

billhay4, 

High Lonesome Valley, 

Jim Adwell, 

Kennyz55

----------


## Stephen Perry

The big problem with science as applied in the small shop world is the serious limitations on time available to design and perform experiments.  It's an issue.  I run across nice little research problems all the time, and very quickly realize I've outlined a master's thesis type effort.  It's a shame, because so much can be done.  I used to have software and nice microphone set up and so on, take notes and attempt to compile things, and it just ate too much of my time, and I never ever had enough of an N to start to separate signal from noise with any degree of rigor.  Were I the science guy at a big production facility I'd be feeding research projects to eager students all over the place, if I could find them.  Oh well!

I'm going to concentrate on a different aspect of the bridge thing over the fall.  First, Rebecca and I will develop a decent production-oriented bridge design based off the violin bridge model.  There are some aspects not addressed by current designs.  I don't know if this is feasible.  I would like to make an adjustable one that acts like a solid one, as others have done, but am not convinced I can do any better.  So that would be a later modification.

I'll get whatever seems to be the accepted program for acoustical analysis and set up for measuring things.  I am not convinced that the acoustic things that need to be measured are the ones we usually measure.  But for simple variables I suspect there's a good deal of usefulness there.  Mass is one of those simple variables that can be addressed without much work.  Foot contact area and location might also be addressed fairly easily.

There are some other aspects of bridges for mandolins that interest me, too.  Getting the bridge to not filter out good things is one, as we do with violin bridges.  That is actually my primary goal.  Width is also of great interest.

As to lecturing, I got really disappointed with the whole lecture model.  Right away.  I don't like it.  I used to give talks / classes to industry groups. I would immediately get everyone into working on things, engaged discussion and the like.  Nothing like having a group of execs on their hands and knees poking at a 6' x 6' geologic map and giving them crayons.  Some real results come from that.

I only remember one lecture class, by Hopkins at UVA, that had a lasting impact.  On the other hand, I remember my lab and especially my field courses very well.  My single most important educational lessons were in music, which bled into everything else.  One from Max Camp at USC who showed me how to play a single note on a piano, and one from Lily Afshar at a master class where we discussed aim-directed movement in shifts up and down the fretboard.

At this point, I suspect the academic system is really broken.  The educational style used doesn't work, and the students are different now.  Interesting article in The Atlantic, Sept 2014, on "The Future of College" - I just skimmed, but it really seemed to be an interesting viewpoint.  Must read in detail.  Important on this end because Rebecca wants more education and I'm thinking the traditional approaches are a scam.  Of course, I grew up in more of an apprenticeship mode with mechanics and so on.  So I began with a bit of a jaded view.  The coming mix of ala carte self-education, internships, etc really interests me a great deal.  I am very glad I did not get stuck with being a teaching grad student.  Probably would have warped my brain.  Equally glad I didn't get on the tenure track train, although that would likely have been more stable and financially rewarding!  I would have done very well in a military track, as I am sort of guiding my son to be in, because of the imposed structure.  At the time, that would have certainly involved SE Asia, and probably a large amount of no-fun.  

Regardless, fun times with mandolins!  

Be well

----------


## High Lonesome Valley

> I am not responsible for your brain ache, nor is my subject matter.  You will have to take responsibility for your own problems with things mathematical and empirical.  
> 
> Aside from your medically diagnosed problems. many people who steer away from things mathematical and scientific do so for a couple of common reasons.  One of those reasons is a low opinion of their own capabiities.  Another is a temperament lacking the patience to deal with abstractions and symbolic representations.  Mathematics and the physical sciences based in mathematics require the patience to stay with a problem until you get it.  That kind of thing does not come immediately to anyone.  Everyone who does those things has to put in the time.  No one who gives up easily will get there.
> 
> As for the "feel thang", I can only offer that music itself, let alone musical acoustics, is just filled with mathematics.  Doubtless you won't take my word for that, but if you were to take the time to look deeply into the matter, you would find it to be true.
> 
> Regarding Stephen's glib retort: Lecturing has been a significant part of my job description for all of my working life, and still is on occasion.  I love the subject matter, and so I have done the lecturing gladly.  Old habits die hard.  One thing I _don't_ do is sling baloney.
> 
> http://www.Cohenmando.com/


You've exceeded Maslow's Hierchy fer sher, Dave.

Just sayin'.  I know 80 year olds who are young, and 40 year olds who are old pharts, and have noticed that setting a cynical and narcissistic course as a youngster can have negative consequences over our too short lives.

Please share the five levels of Dave-ization.  And, for the purposes of this thread, apply them to practical luthiery, which might be considered only the fourth, and more base, level, but still a necessary passage nonetheless. 

You're good at what you do, no doubt.  Now, about your people skills...

----------


## Pete Jenner

As one who has met Dave and had the privilege of chatting to him in his home prior to going out to dinner with him and John Hamlett, I take exception to your comments. Dave's people skills are exemplary. Dave has a witty, dry sense of humour and is an absolute gentleman. He is a font of knowledge when it comes to the science involved in how stringed instruments work. You should pay close attention to his posts and be grateful that he has shared the fruits of his research and his wisdom with you. I am.

Pull your head in mate.

----------

Bernie Daniel, 

Dale Ludewig, 

dang

----------


## Jstring

Ugh. The snippy comments in this thread are pretty unpleasant. 

One of the things that makes the Cafe special is that world-class luthiers take their time to discuss construction principles with those of us who are just players. You don't get that anywhere else! I'm grateful that they are part of the Cafe, and they make the forum worth reading.

HLV, you've now insulted Marty Jacobson and Dr. Cohen, two top-notch builders who are always willing to share their knowledge with the rest of us. I hope that your comments don't discourage any of these luthiers from continuing to post, because we really appreciate their participation.

----------

Bernie Daniel, 

dang

----------


## George R. Lane

I would politely ask the moderators to lock this thread as it has gotten very nasty. I don't understand the physics of the bridge and top plate and neither do I need to, that is the realm of Dr. Cohen and others. I just like playing my mandolin and I think we all need to take a breather and go play some music.

----------

dang

----------


## dang

> So your conclusions really only applies to underbuilt / over-strung instruments, correct?





> If it wasn't either under built or overstrung why would the top be caving in?





> It's now neither thanks to American ingenuity, that's the whole point of this bridge exercise.


In your own words you validated that Marty had a legitimate question.

Now you question Dave's people skills?  Or are you responding "in kind" again?

I will second the request, LOCK THIS THREAD - no more good can come from it.

----------

Bernie Daniel, 

Pete Jenner

----------


## Stephen Perry

Actually, the aspects of mass and contact area are pretty interesting, and if we focus on bridge aspects all will be well.

----------


## High Lonesome Valley

> Actually, the aspects of mass and contact area are pretty interesting, and if we focus on bridge aspects all will be well.


So I took one of the Bigfoots and applied my approach to banjo bridges.  It seems that when I went to record, the OP bridge, although great live, took a second to another prototype.

The other prototype recorded well on the wound strings, but didn't shine on the unwound.  I inserted a piece of bone on the mahogany saddle/middle ply portion and, voila, what works on the banjo works on the OM.  Different density saddle/slot material, even just a sliver under the individual string, makes a remarkable difference string-to-string.

----------


## Stephen Perry

On a guitar, the saddle makes immense difference.  Material, fit, ramp angle.  Can dull down overly bright strings with a stroke of a file on the underside.  Things like that.  I haven't done much work on that stuff.

An aspect of mandolin bridges that I am curious about is the relationship of the feet contact points to the tone bars.

----------


## High Lonesome Valley

> An aspect of mandolin bridges that I am curious about is the relationship of the feet contact points to the tone bars.


I know violin a little better than mando.  The violin treble bridge foot doesn't rest directly over the sound post, the post in relationship being slightly toward the bottom from the bridge, and lateral from foot for desired tone.  The bass foot rests directly over the bass bar.  I think this more or less reflects mandolin bracing, except doesn't the treble bar sit medially to the treble foot?

http://www.swstrings.com/learningcenter/soundpost

I wonder what a violin corpus with a retro'd mandolin neck configuration would sound like?  A flat-pick-plucked violin sounds like nothing else in the world, even with the dreaded sound post.

Another thought.  Have you ever heard of a mandolin with a bass bar on bass end and just a sound post on treble end (no treble bar)?  I haven't, but just thinking, violins and mandolins being siblings and all.

----------


## Bill Snyder

HLV, there are several threads that come up with the notion of a sound post in a mandolin. General consensus is they sound terrible. Primary reason given is that the violin is driven with a bow and the mandolin is driven with a pick. Ie, the bow is a sustained force and the pick is a quick attack.

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## multidon

Both of these ideas have been tried and discussed here. Putting a mandolin neck on a violin corpus has not worked out. The violin body is not built to take the additional string tension. Likewise a sound post in a mandolin has been tried as a cure for a sinking top. It kills the sound. It would appear they are two different animals despite seeming similarities. Not "siblings" or even kissing cousins. Violins are descended from the Rebec and the Viola da Braccia while the mandolin is descended from the lute.

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## Pete Jenner

> Another thought.  Have you ever heard of a mandolin with a bass bar on bass end and just a sound post on treble end (no treble bar)?  I haven't, but just thinking, violins and mandolins being siblings and all.


Ok - at the risk making complete idiot of myself (a condition from which I have an innate proclivity never to resile), I'll have a crack at this one.

1. This information has been covered in forums (including this one), blogs, publications and other discussion formats far and wide.

2. If it was a good idea, someone would have done it and it would have caught on. As it is, some people HAVE done it and it HASN'T caught on.

3. Violins and mandolins, far from being siblings are not even in the same family and if they were organisms, I doubt they would fall into in the same order. 

4. Mandolins are high tension instruments. Violins are low tension instruments. Violins have a shorter scale and half the strings of a mandolin.

5. Mandolins are plucked and fretted. Violins are bowed and not fretted. 

Why would you want to do it? What are trying to demonstrate of achieve? Are you suggesting leaving out a brace to accommodate the soundpost (thereby compromising lateral stiffness of the soundboard)? Do you think a soundpost would improve the coupling of the plates? It won't - the ribs do a fine job of that already.

You will find that the soundpost will mute the top at certain frequencies and most likely interfere with the plate modes.

A bass bar is just a longitudinal brace that's too fat and will likely rob the instrument of the very thing you wanted to reinforce - bass.

No doubt I will be corrected on some of the technical stuff. 

If you build such an instrument don't expect it to be the next new thing in mandolins or even sound like a mandolin. 

As far as I'm concerned it's analogous to sticking a platypus bill on a wombat or a kangaroo pouch on a dingo.

Cheers cobber.

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Bob Clark

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## Jeff Mando

> Ok - at the risk making complete idiot of myself (a condition from which I have an innate proclivity never to resile), I'll have a crack at this one.
> 
> 1. This information has been covered in forums (including this one), blogs, publications and other discussion formats far and wide.
> 
> 2. If it was a good idea, someone would have done it and it would have caught on. As it is, some people HAVE done it and it HASN'T caught on.
> 
> 3. Violins and mandolins, far from being siblings are not even in the same family and if they were organisms, I doubt they would fall into in the same order. 
> 
> 4. Mandolins are high tension instruments. Violins are low tension instruments. Violins have a shorter scale and half the strings of a mandolin.
> ...


Wait, you're telling me a violin and mandolin aren't the same thing?

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## Pete Jenner

> Wait, you're telling me a violin and mandolin aren't the same thing?


Well if you don't know then yes I'm telling you but if you did know, that could explain why you aren't Jeff Violo.

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## High Lonesome Valley

> Both of these ideas have been tried and discussed here. Putting a mandolin neck on a violin corpus has not worked out. The violin body is not built to take the additional string tension. Likewise a sound post in a mandolin has been tried as a cure for a sinking top. It kills the sound. It would appear they are two different animals despite seeming similarities. Not "siblings" or even kissing cousins. Violins are descended from the Rebec and the Viola da Braccia while the mandolin is descended from the lute.


Neck to corpus-string tension makes sense, but maybe lowering the neck angle to reduce string tension...just thinking.

Also wondering if what you and Multidon are referring to regarding a soundpost in a mando with an existing treble bar or a soundpost replacing the treble bar altogether.

Regarding the relationship of mandolin/violin, they both seem to have a common origin and outcome, and a guitar might be a better example of the evolution of the lute than the mandolin.  So many similarities and, I think, divergent string configurations as the main difference.  Pre mandolins/pre violins were just varied examples of lutes, same construction, same scale, with a bow as the main difference.

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## multidon

Here is an old thread about converting a violin to mandolin: http://www.mandolincafe.com/forum/sh...ht=violin+body

Here is a spirited discussion about soundposts in mandolins: http://www.mandolincafe.com/forum/sh...ight=soundpost

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## LongBlackVeil

I've never heard of anyone actually designing a mandolin with a soundpost instead of tone bars . Usually when were talking about soundposts in mandolins, were talking about adding a post to an existing mandolin to support the top.

Not saying it hasn't been done, there's a lot of stuff I haven't heard of

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## Pete Jenner

Very good Don. Post #24 in that thread by Dave is particularly informative as it explains the importance of asymmetry to the low frequencies.

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## Pete Jenner

> I've never heard of anyone actually designing a mandolin with a soundpost instead of tone bars . Usually when were talking about soundposts in mandolins, were talking about adding a post to an existing mandolin to support the top.
> 
> Not saying it hasn't been done, there's a lot of stuff I haven't heard of


Ok - now we are getting into spooky territory.
Mandolin tone bars are braces - they improve lateral stiffness of the soundboard. In violins, lateral stiffness of the soundboard is not an issue. A sound post is not a brace and is not there to provide 'support' for the top.

You people should read books and do some research before putting out all this speculation based on what you imagine to be the truth. The very least you could do is read the thread that Don posted and the best you could do would be to read the peer reviewed research that Dave spends most of his time here trying to get you to read. Don't be lazy readers!!!

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LongBlackVeil

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## LongBlackVeil

> Ok - now we are getting into spooky territory.
> Mandolin tone bars are braces - they improve lateral stiffness of the soundboard. In violins, lateral stiffness of the soundboard is not an issue. A sound post is not a brace and is not there to provide 'support' for the top.
> 
> You people should read books and do some research before putting out all this speculation based on what you imagine to be the truth. The very least you could do is read the thread that Don posted and the best you could do would be to read the peer reviewed research that Dave spends most of his time here trying to get you to read. Don't be lazy readers!!!


Agreed

I meant to support a sinking top, but still What I said made no sense :Smile: 

I know little to nothing about building and repairing, what am I even doing here?! Back to talkin about my favorite strings

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Pete Jenner

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## billhay4

Actually, there is debate about whether soundbars are braces at all. Many will argue that their primary function is tonal and that the arching of a top is what gives it its structural strength.
That being said, this is debated.
A sound post, however, does not function well on a mandolin in large part because the means of exciting the cavity is different -- plucking strings instead of bowing them. It's been tried and discussed here quite often.
Frankly, everyone in this thread needs to take a more collegial attitude for none of you knows enough about mandolins or violins to be authoritative. I would argue no one really does. The spirit of this, and all, threads here should be to share ideas, not fight with each other. Too much snarkeyness here to suit me.
Bill

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Larry Simonson

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## LongBlackVeil

> Actually, there is debate about whether soundbars are braces at all. Many will argue that their primary function is tonal and that the arching of a top is what gives it its structural strength.
> That being said, this is debated.
> A sound post, however, does not function well on a mandolin in large part because the means of exciting the cavity is different -- plucking strings instead of bowing them. It's been tried and discussed here quite often.
> Frankly, everyone in this thread needs to take a more collegial attitude for none of you knows enough about mandolins or violins to be authoritative. I would argue no one really does. The spirit of this, and all, threads here should be to share ideas, not fight with each other. Too much snarkeyness here to suit me.
> Bill


I thought this was fact and not debated, because my very first mandolin, a loar 400 something or other, had no braces of any kind

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## Pete Jenner

> Actually, there is debate about whether soundbars are braces at all. Many will argue that their primary function is tonal and that the arching of a top is what gives it its structural strength.


There is also a debate going on somewhere about whether the moon is made of Danish blue cheese or Swiss cheese. 'Soundbars/tonebars' are braces! You know that Bill - or you should.





> Frankly, everyone in this thread needs to take a more collegial attitude for none of you knows enough about mandolins or violins to be authoritative. I would argue no one really does. .


Nonsense!!!




> The spirit of this, and all, threads here should be to share ideas, not fight with each other. Too much snarkeyness here to suit me.
> Billc.


Snarkyness has nothing to do with it. People who speak out of their bottoms on a serious forum about mandolin building need to be corrected. Or we could all just drift off into la-la land and pretend the sky is pink.

How do you think wars start? As a result of arguments? NO - through ignorance and the shared belief that wrong is right because it was the loudest and most pervasive point of view.

There - I have broken my response up into easy to digest chunks for those who can't read a whole paragraph without getting bored. The sound bite generation rule the earth. It was nice knowing you Earth.

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## LongBlackVeil

> There is also a debate going on somewhere about whether the moon is made of Danish blue cheese or Swiss cheese. 'Soundbars/tonebars' are braces! You know that Bill - or you should.
> 
> 
> 
> 
> Nonsense!!!
> 
> 
> 
> ...


How do you explain the mandolin with no bracing then? Serious question, I'm not trying to suppose that you are wrong or anything like that. I'm just curious, if the primary role of tone bars is bracing, then why do we have mandolins with no bracing at all.

I do realize this is not a common thing, for a mandolin to not be braced on the top. But still I don't think Loar would be building them like this if they thought the top would collapse or anything

I would also make the argument that this thread drifted into lsh lsh land before I got here  :Smile:

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## Pete Jenner

Thick top - light strings - short scale? You name it - many possibilities.

As I understand it, many Gibson tops that had a single transverse brace have collapsed.

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## LongBlackVeil

> Thick top - light strings - short scale? You name it - many possibilities.
> 
> As I understand it, many Gibson tops that had a single transverse brace have collapsed.


well if those are the only options, then it must be a thick top. The Loar mandolins are all standard loar type scale and can of course be played with standard gauge strings.

I wonder though, if it does have a thicker top, is that necessarily a bad thing? Heres a thread about the lm600 vs the lm700. One is braced one is not. Notice how many prefer the non braced version. Anecdotal? sure. But i think a debate about whether tone bars main function is tone, or structural support, isnt quite as silly as an argument about the moon being made of cheese.

http://www.mandolincafe.com/forum/showthread.php?76460

I'd also like to see some measurements of the top of the 600 vs the 700. Maybe the top is thicker, maybe its not. idk

Here is a quote from Robert Fear of Folkmusician




> "There is nothing on the underside of the LM-700 tops. They are carved a bit differently because of this. As far as being structurally sound, I don't see why there would be a problem. Tone bars add some structural support, but it is not really what they are meant for. There is no reason to think a properly carved archtop instrument would need additional support."


Here is a quote from Allen Hopkins, with another quote inside this quote from Big Joe Vest




> "Carved-top mandolins don't have to have braces per se, since the top thickness is graduated and can be made thick enough for structural solidity. Violins, also with carved tops, don't have "braces," but do have tone bars to provide structural support and produce the proper acoustic "voice." For those carved-top mandolins that are braced, there are a variety of configurations: X-bracing, a single lateral brace, tone bars (singular or plural).
> 
> Here's part of a response that Cafe member (and Loar fan) "Big Joe" Vest gave to a thread on Loar bracing, a couple years ago:
> 
> The LM300 does have an X brace and they are very nice mandolins. Whether a mandolin has bracing or not is secondary to a lot of other issues. Most mandolins, even in the sub 1000 category, will have bracing of some kind. That may be as much of a problem as a solution. Remember the purpose for the braces is not structural integrity in an arched top instrument but rather tone enhancement in a particular tonal spectrum. You can alter the sound of an arched top instrument by the way you alter or eliminate the braces. In other words, a tone bar will deliver an emphasis on a certain frequency or tonal spectrum and an X brace will enhance a bit different set and no braces will enhance yet another spectrum. Tone bars are often more focused in the mid range as is often seen in Bluegrass. The idea is that it cuts through the guitar, fiddle, and banjo better than one not so highly focused in that range.
> 
> In practical application there is a lot of truth to that, but many want a different sound either because they are not playing in that same kind of ensemble or much of their playing is by themselves and they prefer a broader tonal spectrum. In that case X bracing or no bracing can be an option.
> 
> More important than just what kind of bracing or whether they even have bracing is the overall build of the mandolin. If it is a pressed top arch it will not be as good as a carved top. If it is laminated rather than solid it will not be as good If it has a poly finish rather than nitro cellulose it will not be as good. If it has really cheap hardware then it will not be as good. The way it is setup may be one of the most important criteria of all in this whole equation.
> ...


All respected members claiming that tone bars primary role is tone shaping , not structural support

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## Pete Jenner

We had a thread about this a while ago and I was the one advocating trying no braces. I was very very wrong and have learned the importance of lateral stiffness. I'm always happy to admit when I'm wrong.

With all due respect to the quoted people, they haven't got the creds of a Dave Cohen or a John Hamlett IMHO. They can bleat on until the cows come home about tonal and timbral control (not that they ever separate the two). The fact is that increasing or decreasing the amount of wood on a braces raises or lowers the frequency of the main modes because you are changing the mass of the unit. Braces provide a very convenient way of controlling the mass of a top. Other than that, 'tone bars' are braces and provide lateral stiffness to an otherwise anisotropic lump of wood - period.

Yes the cheese/moon debate is really nuts. Everyone knows it's made of cheddar.

Sleep time now - night.

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## LongBlackVeil

> We had a thread about this a while ago and I was the one advocating trying no braces. I was very very wrong and have learned the importance of lateral stiffness. I'm always happy to admit when I'm wrong.
> 
> Yes the cheese/moon debate is really nuts. Everyone knows it's made of cheddar.


well you couldn't have been THAT wrong, because these Loar lm400 and lm700 mandolins have been around for quite some time and i would say they've been pretty successful, without any kind of bracing. Now they might have thicker tops, but is that necessarily a bad thing if they sound good?

Now, i was in no way saying that the ops idea of designing a mandolin with a soundpost replacing a tone bar. I was simply saying i had never heard of it being done. Your probably right, it probably wouldnt sound good. 

Btw ill also admit im wrong happily, i actually very much live by the quote in your sig line, "the more i learn, the less i know". I know very little about mandolin construction and absolutely nothing about violin construction.

Ive built an electric guitar before, but a monkey could do that  :Smile: 
and, the moon is made of very very old cottage cheese quite clearly

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## multidon

I just have to say, this is the most entertaining thread we've had in the Builders and Repair domain for some time now! I am thankful that the moderators have not closed it down (yet!)

Weren't we talking about lightweight bridge design? How did we get to sound posts and braces and tops and what the moon is made from?

Mandolin design really seems to bring out the strong opinions. Please continue.

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Bob Clark

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## Stephen Perry

I'll just pop this here.

And say I have a violin bridge concept mando bridge sketched out in draft in front of me at the moment.  Starting to work on the details and fabrication concepts.

What is the function of the long span of bridges across the top?

On the symmetry thing, I figured the differential location of the tone bars was to gain asymmetry for a bit better bass response.  The barless ones sort of baffled me, so I got a beer and forgot about them.  Very effective solution!

Soundpost in a guitar can fix a few things, but the things have to be pretty wrong!!!!

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## Jeff Mando

> Soundpost in a guitar can fix a few things, but the things have to be pretty wrong!!!!


The Gretsch guitars that the rockabilly players like use Trestle bracing, which is basically a sound post connecting the front to back to reduce feedback when playing live.  Of course, we are talking electric hollow-body guitars.....

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## multidon

I guess the ultimate sound post is the big maple block in a Gibson 335, then. Also to prevent feedback. But I thought that we were talking about a literal post similar to one found in a violin.

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## High Lonesome Valley

> Ok - now we are getting into spooky territory.
> Mandolin tone bars are braces - they improve lateral stiffness of the soundboard. In violins, lateral stiffness of the soundboard is not an issue. A sound post is not a brace and is not there to provide 'support' for the top.


Thanks, Multidon, for the links.

I view the soundpost as a movable vertical brace used to dampen or enhance specific frequency response (sonic), and that without the post the top would start caving (supportive).  So much force as a brace that the back often gets cracked just below the soundpost.  The bass bar has the same purpose on the violin and the mandolin and is subject to bridge-induced cracks but, versus a soundpost, a two-functioned lateral brace (sonics and supportive).  Both the violin and mandolin changed from ladder bracing to lateral bracing.

Pete, what about location of feet specific to treble and bass feet in relationship to the bars and, on violin, bass bar and soundpost? Also wonder if changing the footprint of, say, the treble foot to larger or smaller will enhance a specific frequency.

Reviewing the old posts from Multidon, and all theorizing aside, I still wonder like LongBlackVeil if anyone has replaced the treble bar with a soundpost, rather than just leaving the treble bar in and using a soundpost as additional support.

It's understood that a soundpost, in addition to the already installed treble bar, would kill the sound.  Just the same way adding a second treble bar would kill the sound.

Double strung violins have been successfully made, so the string pressure issue has been addressed in a violin corpus.

I have recorded with a flat-picked violin, incredible percussive attack (a la Dave Matthews Band), quick decay, sounds like a one-stringed "dead"-sounding mandolin and a real enhancement to the production process.

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## Pete Jenner

HLV, it has been shown that without a soundpost, tops don't cave in.

As I understand it from previous threads, location of the soundpost in a violin is entirely dependent on the location of the node in a particular plate mode and is in fact located ON a node somewhere behind (closer to the tail than) the treble foot of the bridge.

I can't comment on foot size as I don't know and any speculation on my part would be just that - speculation. I don't know enough to make any further useful contributions to your post. I do understand that the bass bar and soundpost in a violin set up an asymmetry in the way the plates vibrate but I am yet to fully understand why this is important.

I believe in the science and when presented with it or upon reading the research I take it on board.  

I'd actually prefer to find out more about 'wolf tones' in cellos and basses and find a way to control those frequencies in the build process (much like the soundpost dissipates horrible screechy high frequencies) rather than having to clamp a lump of metal on the D string behind the bridge.

Having said that, I rejected the moon/cottage cheese conjecture, I am leaning towards the view that the moon is actually white stilton and only appears yellow because of the refractive indices of various elements in the atmosphere.

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## billhay4

Pete,
Your agressive, combative attitude is not only getting tiresome, but is really not in the spirit of the Cafe. You only joined the Cafe in 2011 and have been building instruments for only a few years, but somehow have come to decide who is talking out of their butt, who is an authority, what is right and what is wrong.
You need to tone it down a notch or two.
But you're not the only one here, especially in this thread.
That's all you'll hear from me on this subject.
Bill

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## Pete Jenner

> Pete,
> Your agressive, combative attitude is not only getting tiresome,


It's not my fault you are an ignoramus Bill. Have a nice life or get one.

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## fscotte

Pieces of wood on the underside of a top are braces when the top is too thin to support the force of the bridge, and they are toneshapers when the top is too thick to achieve the necessary deflection for a good tone. 

In other words, they are whatever the particular builder wants them to be.

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LongBlackVeil

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