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I'm interested in hearing why most 'flat topped' guitars have a pin bridge rather than a floating bridge. It appears to me that archtops need a floater because of structural considerations, but I've noticed in old pictures and such that there 'used to be' more flat tops with floating bridges than are made in modern times, like back in the 1920's, 30's, and 40's. Is the pin bridge really superior for particular reasons, or is it a style preference?

I'm learning that many of the 'tried and true' 'traditional choices' of materials and techniques in lutherie are for good reasons, and have been arrived at by trial and error by our predecessors. I'm not challenging the use of pin bridges, but in several years of frequenting forums and reading I don't think I've seen much, if any, discussion regarding the issue of Pin vs. Floating Bridge.

Just offhand, the Floater appears to have advantages for a number of reasons. If the more difficult Pin Bridge is superior, why? I'd like to know.

Any info, or opinions?

CrowDuck

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Chris Nielsen
Soquel, CA.

It stays put.

you can change strings all 6 at a time without worrying about intonation falling apart.

I've built a jig for alligning the bridge on the guitar using a temporary tailpiece. If I'm honest, I'm just not accurate or patient enough when it comes to measuring!!! this lets you fine tune sideways too.....

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My soundclick xx luthier blog xx luthier soundclick

I believe that pin bridges transfer more energy from the string to the top via
the rotational force they exert. Greater volume, enhanced tone.

A flat-top guitar with a floating bridge just wouldn't sound like a flat-top as we know it. When the bridge is glued, and the strings are anchored at the bridge, the string energy causes the bridge (and the top around it) to move in all directions--up & down, rocking side-to-side, and tipping front-to-back. A floating bridge, with the strings necessarily anchored elsewhere, is limited in its movement, or so I've read. If I remember correctly, most of the movement is in the up & down direction. Also, as Yukon alluded, when the strings are anchored as they are with a glued bridge, you get more energy transferred because of the greater break angle at the saddle. Trying to make a floating bridge work as well as a glued one would be an engineering nightmare, and likely add considerable weight to the instrument. So, yeah, sometimes the way it's always been done is, indeed, the best way--at least until someone comes up with something completely new, of course!

Having a floating bridge on a flat top guitar would make it sound closely to an Irish Bouzouki, a very high-end sound. I would only recommend a floating bridge on an arched-top guitar as it receives the increased down ward tension created by the arch,
The same structural principle applies to the violin family.

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Michael Lloyd

“I was born to ignorance, yes, and lesser poverties ...
I was born to privilege that I did not see ... I didn’t know it, but my way was paved” – John Gorka

Not entirely convinced by the break angle argument (vide infra.)

Agree that the principle method of excitation differs, resulting in a different quality of sound (does a Selmer guitar sound like a bouzouki? Some bouzouki do sound guitar-ish, but I think sound board shape, scale/tension and body volume influence this at least as much (just subjective opinion.))

(This is almost undoubtedly my failing here - if someone could direct me to appropriate references, it would be much appreciated.)

With a floating bridge there is an optimum range between about 13 and 14 degrees - too shallow results in an inefficient coupling, too steep and top excitation is suppressed as the top is pushed towards the bottom of its elastic range (probably misusing words here, but may make sense anyway )

Has anyone build pin bridged instruments with an extension to the bridge to investigate break angle differences? My suspicion is that there is a point beyond which no further improvement will manifest, as once the break angle is sufficient to counter the vibrating string's tendency to uncouple from the saddle, further increases in angle will have no bearing on transmission.

(To put this in context, whereas the majority build induced arch topped guitars here, I'm making mandolin family instruments - induced arch and floating bridge.)

Cheers
Steve

As Steve said, and as far as I can tell, you need about 12-15 degrees of break angle at the saddle to keep the strings from 'hopping' off as they vibrate. It's hard to see how more than that would effect the sound, but many people insist that it does. I lack the experimental data to argue with them about that.

Somehow you've got to induce the strings to make that angle. On a flat top simply leading the strings over the saddle and tying them off at the tail usually won't cut it. On resos they actually jam them into notches that grip the strings. On pianos, where they are stuck with a flat break angle, they run the strings between a couple of pins that bend them sideways. On Neapolitan mandos and other related instruments, like the old citarra battante, they 'crank' the top, creasing it across the width just behind the bridge and pushing it down toward the tailblock. This, of course, totally changes the way the top works.

Flat top guitars have genearlly used two methods, the tie bridge and the pin bridge. The tie bridge is a holdover from the lute, where the bridge is pretty much what we call the tieblock on a modern classical guitar. The seperate saddle seems to be a later addition. The pin bridge seems originally to have been adapted to the guitar from the harp. It lends itself to use with steel strings, since it does not require tying a knot that would tend to break the wires. Either way, the strings are anchored at a point below the top of the saddle, thus getting the break angle they need, at the cost of torqueing the bridge.

Some of the early 20thC flat top guitars that used floating bridges, such as the 'Stella' 12s, had a tailpiece that was designed to force the strings downward a bit. They may also have relied on string notching as the resos do. I'm not as certain of the mechanism on Selmer/Maccafferis. They may have used a relatively high dome, similar to what the old 'English guittar' used, imposed by curved cross braces.

The actual 'torque' signal cuased by changing string tension on a fixed bridge is generally much smaller in magnitude than the vertical 'push' of the strings on the top can be. Guitars with fixed bridges also have to be built to resist that torque, so the small force available may not result in a lot of sound output. Since instruments with floating bridges normally have the necks set at a back angle, in part to get the needed break angle, the tension change signal that torquues the bridge on a fixed-bridge instrument serves to push downward on the top of an archtop. This is actually a more effective way to produce sound, so it's possible that the archtop gets more benefit from the tension change than the flat top does. In either case, I'm pretty sure it's not the _main_ way that sound is produced, although it could contribute to the 'color'.

Didn't pinned bridge develop when soundboard bracing improved. The heavier braced top would still be as resonant as a floating top guitar with trapeze tailpiece etc. Less hardware, more "modern" and streamlined.

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Greg
http://garibaldiinstruments.com/

Pinned bridges go 'way back. I worked on an 1844 Panormo with an early form of fan bracing that had a pin bridge. I got to work on it because the fellow who got it out of his grandmother's attic tried putting steel strings on it. The windings caught and chipped the bridge before he got it up to tension, which would have ripped the 1-piece top right off it. Anyway, even earlier ladder-braced tops used pin bridges, too. The Spanish are the only ones who seem to have retained the 'traditional' tie block bridge once the pin bridge came into use. I rather suspect, as I say, that the pins were picked up from the harp, and were used at least in part simply out of fashion at first.

Couple of years ago I repaired this anonymous 1780s London guitar for the RCM museum that had a pinned bridge, they go back even earlier than that to the 1750s at least.





By the way this is one of the sweetest sounding guitars I've ever played.

Colin

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I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

...or you could use a hybrid approach:




... and either shave your X-braces to your heart's content, or re-think the old X-brace paradigm in favor of something that supports sonic production rather than holds the guitar together.

Dennis

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Dennis Leahy
Duluth, MN, USA
7th Sense Multimedia

Dennis wrote:
"... re-think the old X-brace paradigm in favor of something that supports sonic production rather than holds the guitar together."

In the first place, the stress that kills tops is, IMO, the torque on the bridge, and the design you show doesn't reduce that by much, if at all.

There _have_ been a lot of designs tried out over the years that reduce the load, and the bracing, on the top of the guitar. If you poke around in the dusty closets of luthiers you'll find that they are not uncommon; almost everybody seems to have tried out one brainstorm or another at some point. I think the fact that they have generally not caught on says something about how successful they have been as designs.

We have to keep in mind that we're in an 'ecosystem' where there is heavy selective pressure. If some new design or feature is even a little better than the 'normal' stuff, it will catch on very quickly. Torres' synthesis of the best features of the Spanish guitars of his period drove most other designs out of the high-end market within a few years, according to Richard Brune. X-bracing became the 'standard' for steel string flat tops for good reasons. If you stick with traditional materials, it's hard to make meaningful improvements in the designs we have, I think. Nomex and carbon fiber open up all sorts of possibilities, which may take a few years to fully work out, but that's another chapter in the ongoing saga.

I guess the point is that it's easy to grumble about the deficiencies of the guitar: it's not 'loud enough', and so on. But I'd be willing to bet that it's nearly impossible to think up anything much better using traditional materials. If it were easy, somebody would have done it already, and it would be the 'standard' design that everybody grumbled about.   

I have only heard a couple floating bridge flattops cheapies at that, they seemed to have less sustain than those of comparable build with fixed bridges.

Is there a difference in sustain?

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"It's a Tone Faerie thing"
"Da goal is to sharpen ur wit as well as ye Sgian Dubh"
"Sippin Loch Dhu @Black lake" ,Kirby O...

[QUOTE=Alan Carruth] Dennis wrote:
"... re-think the old X-brace paradigm in favor of something that supports sonic production rather than holds the guitar together."

In the first place, the stress that kills tops is, IMO, the torque on the bridge, and the design you show doesn't reduce that by much, if at all.

There _have_ been a lot of designs tried out over the years that reduce the load, and the bracing, on the top of the guitar. If you poke around in the dusty closets of luthiers you'll find that they are not uncommon; almost everybody seems to have tried out one brainstorm or another at some point. I think the fact that they have generally not caught on says something about how successful they have been as designs.

We have to keep in mind that we're in an 'ecosystem' where there is heavy selective pressure. If some new design or feature is even a little better than the 'normal' stuff, it will catch on very quickly. Torres' synthesis of the best features of the Spanish guitars of his period drove most other designs out of the high-end market within a few years, according to Richard Brune. X-bracing became the 'standard' for steel string flat tops for good reasons. If you stick with traditional materials, it's hard to make meaningful improvements in the designs we have, I think. Nomex and carbon fiber open up all sorts of possibilities, which may take a few years to fully work out, but that's another chapter in the ongoing saga.

I guess the point is that it's easy to grumble about the deficiencies of the guitar: it's not 'loud enough', and so on. But I'd be willing to bet that it's nearly impossible to think up anything much better using traditional materials. If it were easy, somebody would have done it already, and it would be the 'standard' design that everybody grumbled about.   [/QUOTE]
Hi Alan,

Interestingly, after I did this, I saw a patent by Ned Steinberger for a "stress-free bridge" that was a similar concept. Ned exited the holes at the back of the bridge at the same height as the saddle, and had an elevated tailpiece that in effect eliminated the torque. So, my design eliminated shear, and Ned's eliminated shear and torque. A few prototypes were built by Steve Grimes. By the self assessment of Ned Steinberger, and by my own results, I honestly don't think anyone has hit a home run with these concepts yet. However, I do think it has proven some engineering concepts that should enable someone to surpass what can be done with an X-brace, both in terms of timbre and loudness, and in terms of instrument longevity. I don't think anyone should abandon X-braces now, and maybe never, but I do hope that some others with an experimental mindset will keep tinkering with this "tunnel bridge" concept (combined with suspended structural bracing) to really check out what the potential is.

Even "in an 'ecosystem' where there is heavy selective pressure", if 99% of guitarmaking luthiers follow closely the path of C.F. Martin, there will be very few "mutants" or "evolved ones" (matter of perspective) to examine.

Dennis

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Dennis Leahy
Duluth, MN, USA
7th Sense Multimedia

Dennis wrote:
"Even "in an 'ecosystem' where there is heavy selective pressure", if 99% of guitarmaking luthiers follow closely the path of C.F. Martin, there will be very few "mutants" or "evolved ones" (matter of perspective) to examine. "

Certainly most of the guitars you'll find up for sale will be more or less closely based on existing designs. This is not just the conservatism of builders: I'd say it's much more conmservatism on the part of buyers. People really don't like to part with their hard-earned cash for things they regard as 'experimental'. Look how long it took Jim D'Aquisto to break out of the mold of the 'New Yorker' that he inherited from D'Angellico. He had all sorts of good ideas, but couldn't really try them out until Chinery gave him a blank check and a green light.

Still, most makers seem to find the time once in a while to try something 'radical'. Nor are players stuck so firmly in a rut that they won't pick up on these things whan they are clearly 'improvements'. Classical players are supposed to be the most conservative of all, but they're paying large sums for 'double/sandwich' tops, and Smallman's lattice, as well as Tom Hunmphrey's 'Millenium'.

Of course, some of the 'improvements' really aren't: I've had the chance to A/B some of those 'improved' designs in concerts next to good 'standard' models, and some of the 'better' ones aren't really, IMO. Fashion and hype have their effect in all fields.

But, on the whole, I think the cream does rise to the top, and fairly quickly. In over thirty years of building and repair work I've seen a lot of 'experiments' that didn't work, and darn few that did. As somebody who has spent a lot of time and effort looking at how guitars make sound, I get the impression that the 'standard' designs are pretty well thought out, and will be difficult to improve on in any major way. I'd love to be proved wrong. I'd like even more to do the 'proving' myself! But I'm not holding my breath. Those old boys weren't stupid.

[QUOTE=Alan Carruth] ... As somebody who has spent a lot of time and effort looking at how guitars make sound, I get the impression that the 'standard' designs are pretty well thought out, and will be difficult to improve on in any major way. I'd love to be proved wrong. I'd like even more to do the 'proving' myself! But I'm not holding my breath. Those old boys weren't stupid. [/QUOTE]
Hi Alan,

No, those old boys were not stupid. But I daresay that if the X-brace that 'ol C.F. put into the early steelstring guitars to keep the top from collapsing also proves to be the ideal and optimum bracing structure for tone and sustain, that C.F. wasn't just a genius; he is a genius squared.

If every single locomotive builder built only steam locomotives, then the very best locomotive in existence today would be a steam locomotive, and the current state of the art in high speed trains would be in shaving steam pistons.

I'll give you an example of what I think is even worse: I read a review of a Kasha braced classical guitar. The reviewer stated that the guitar had a very big voice, the sound was extremely well balanced, and that it sounded "piano-like." He then went on to say that he did not like the guitar, because it did not sound "Spanish enough." So, that mindset is effectively a self-fulfilling prophecy. If you or any other luthier or any player has locked-in the sound of the very best Martin or Martin clone as the pinnacle of perfection of sound possible from an acoustic guitar, then you are correct that Ned Steinberger, and Jeff Babicz, and even beginners like me can rest assured that we will never produce a "better" guitar regardless of the length of sustain, the frequency spectrum, or the timbre of any new guitar.

I believe that you are correct that there are (and always will be) lots of players who want Martin clones, even if someone comes up with something else that is demonstrably "better." That won't keep me from trying!

One thing that may swing the wallets of the buying public may be if some new engineering designs sound about the same as any high quality guitar, but by virtue of the engineering principles, the guitars last considerably longer.

Dennis

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Dennis Leahy
Duluth, MN, USA
7th Sense Multimedia

To me different does not mean better. There are trade offs for every thing Increasing sustain & freq response may give a muddied sound when strumming. Rainsong carbon fiber guitars are a leap in materials but to me they sound lifeless.

                with a little humility
                               Kirby   

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"It's a Tone Faerie thing"
"Da goal is to sharpen ur wit as well as ye Sgian Dubh"
"Sippin Loch Dhu @Black lake" ,Kirby O...

[QUOTE=K.O.] To me different does not mean better. There are trade offs for every thing Increasing sustain & freq response may give a muddied sound when strumming. Rainsong carbon fiber guitars are a leap in materials but to me they sound lifeless.

                  with a little humility
                                   Kirby    [/QUOTE]
Kirby,

I agree, different is not necessarily better. And we also might not agree on what constitutes "better", but a lifeless guitar would certainly not be a worthy goal to me.

And, in case my belief that the X-brace and pinned bridge is probably not the pinnacle of guitar engineering leaves you with a feeling that I lack humility, let me say that if the collective group of all luthiers push forward toward finding new engineering solutions, (especially cooperatively), that guitar engineering is likely to evolve - and evolve quickly. If I'm the only experimenter, then the likelihood is minute.

This isn't a wag of my finger at traditionalists - the vast majority of great guitars I have ever played were "in the mold" of Martin. Though there are still some builders using strictly dovetailed neck joints, hot hide glue, and French polishing, there are quite a few builders that have embraced bolt-on necks, adjustable necks, aliphatic resin glues, carbon fiber, waterborne finishing materials, improvements in guitar string composition and technology, improvements in tuning machines, truss rods, and fret wire, CNC manufacturing, and other deviations from 19th century traditional guitar building. I really don't think it is arrogant or lacking in humility to make an educated guess that anchoring strings at the bridge and compensating for the unwanted forces with an X-brace is just another area in guitar construction that warrants examination, and can probably be improved upon.

Dennis

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Dennis Leahy
Duluth, MN, USA
7th Sense Multimedia

Dennis Leahey wrote:
"No, those old boys were not stupid. But I daresay that if the X-brace that 'ol C.F. put into the early steelstring guitars to keep the top from collapsing also proves to be the ideal and optimum bracing structure for tone and sustain, that C.F. wasn't just a genius; he is a genius squared. "

Except he _didn't_ put it on steel string guitars. C.F.I made gut strung instruments: steel strings came along a generation or more later. X-bracing just happened, for both structural and acoustic reasons, to work better on steel string guitars than any of the alternatives that were tried. Lots of them have been. Some have been nearly as good, but none has been any better, on the whole. Remember, every bracing system is a compromise.

"If every single locomotive builder built only steam locomotives, then the very best locomotive in existence today would be a steam locomotive, and the current state of the art in high speed trains would be in shaving steam pistons. "

Certainly true. Please re-read my post, though. There are 'experimental' guitars by almost all makers, including the very best. Nobody makes 'just' traditional instruments. If those experiments had worked, don't you think those great makers would have used the improvements?

" He then went on to say that he did not like the guitar, because it did not sound "Spanish enough." So, that mindset is effectively a self-fulfilling prophecy. "

The problem is one of back compatability. Any new design has to work for the existing repertoire, as well as offering some improvements, if it is to succeed. If 'loud' were the only criterion, then all guitar players, without exception, would play solidbody electrics. I've built 'loud' classical guitars: my two archtop classicals were both louder and 'carried' better than the best 'standard' ones I've made. But they just didn't sound 'right' for the classical repertoire.

Admittedly, there is an element of self-fulfilment there. The existing repertoire was devised to take advantage of the strengths, and minimise the weaknesses, of the existing instruments. Any instrument that does not share those strengths will not fill the bill. Players learn to play on the existing instruments, and find ways to get more of what they want over time. Those 'tricks' might not work on an 'improved' instrument. The foremost example of this is the violin: you can't do _anything_ differently from the way the Olde Masters did it, or you'll end up with an instrument that is simply useless for some of the existing repertoire. They've pushed the technique so far that something as small as a 1/8" change in string length is unacceptible. To bring it closer to home: Dreads for Bluegrass? Of course! Bluegrass was built on Dreads.

Ultmately, what's 'better' will be determined by the buyers, not by builders like us. I'm an experimenter too: I certainly have nothing against anybody else trying whatever they like. But I do think more makers would be well served to dig around a little, and get a grounding in both the history and the physics of the thing. Historical knowlege will help you by showing what people have already tried, and some physics will go a long way in telling you why something might or might not work. And the _only_ way to know if it does work is to submit it to the merciless judgement of the buying public.

Thanks for your insight, Alan.

Dennis

{edit} And yes, for historical accuracy, I should not say CF Martin I "invented" the X-brace; rather that he and his company "popularized" it.

Builders of the early 19th Century - Early Romantic Guitars (Len Verrett site)DennisLeahy39098.6407060185

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Dennis Leahy
Duluth, MN, USA
7th Sense Multimedia