What are the most common classical guitar bracing patterns, and why did they come into existence? This article will cover the significant acoustic guitar bracing patterns from the original ladder bracing up to the recent lattice bracing and double-top innovations.
All bracing patterns share the same objective; to reinforce the soundboard and minimize any deformations that may occur over time due to the strings' forces pulling on the soundboard. While the braces must reinforce the top, they must also allow it to vibrate as freely as possible.
Today's most prominent bracing pattern is the fan bracing pattern made famous by the luthier Antonio de Torres in the 1840s. It is used in most classical guitars built today.
Braces used in any pattern can be shaped in numerous ways, all of which affect the guitar's tone and the soundboard's responsiveness. Additionally, luthiers who build higher-end guitars will "tap-tune" the braces by slowly removing material to improve the guitar's tonal characteristics. Throughout time, bracing patterns have evolved both as a reaction to technological advances and as a response to guitarists' musical demands.
Basic Bracing Info
As previously mentioned, luthiers can change the shape of the braces without changing the overall bracing pattern. The most famous example of this is the scalloped-braces Martin used in their pre-War guitars and reintroduced in the 1970s. While the scalloped braces are the most famous example, the luthier's imagination is the limit; square, multiple scallops, and half-round patterns are just a few examples. Some luthiers even drill holes in their braces.
Luthiers can also modify an existing bracing pattern by making it asymmetrical. The rationale behind asymmetrical bracing patterns is that the guitar's treble-side and bass-side strings should be braced differently due to the different tension levels on either side. There are two primary ways that a bracing pattern can be made asymmetrical. First, luthiers could run a bar at an angle across the guitar's width that runs between the soundboard and the bridge. Second, luthiers could use additional braces on one side of the guitar. Builders can also shape the soundboard to be thicker in some regions than others; strictly speaking, this is not part of a bracing pattern.
While asymmetrical bracing patterns may seem intuitive, modern science does not agree with intuitive reasoning used to justify it. All strings of the guitar resonate whatever part of the top suits them; they do not merely use the soundboard's closest part. Whether science backs it or not, skilled luthiers have created incredible guitars using both symmetrical and asymmetrical bracing; one is not superior to the other.
There are far more bracing patterns for classical guitars than for steel-string acoustics. I think this is partly due to its less-commercial nature; no single classical guitar maker has ever dominated the classical guitar market in the way that Martin did from the 1900s until Taylor guitars began to challenge its reign. To this day, most mid-to-high-end classical guitars are built by smaller shops that are a fraction the size of the Taylor and Martin. The best classical guitar builders typically have waitlists a decade long and instruments that cost tens of thousands of dollars on the used market. This economic reward may lead to more innovative luthiers building classical guitars due to fewer large-market players and tremendous income potential.
While the classical guitar does have more bracing patterns, development and innovation are still relatively slow, occurring about once a generation. Technological changes typically drive change reasonably quickly; the development of high-tension steel strings helped to popularize Martin's X bracing. The replacement of gut strings with warmer-sounding nylon strings required guitar construction changes to regain some of the lost overtones.
Artistic demands also tend to drive changes. Each generation of performers wants to distinguish themselves from their predecessors; one of the most striking ways of doing this is by playing a guitar with a fundamentally different tone. The rise of a new generation of luthiers also seems to drive development, as the old masters retire and the new masters strive to surpass them.
Braces are typically made of quarter-sawn wood. Wood is considered quarter-sawn when the tree's growth rings are roughly perpendicular to the wood's top. Hardwood floors are one common use for quarter-sawn wood.
Luthiers use quarter-sawn wood for braces because it is a very stable cut; its dimensions won't change much with humidity or temperature. Some claim that it is more robust and stiffer than other lumber cuts, but there is relatively little data to support these claims.
In ladder bracing, a few braces run across the width of the guitar's body. This pattern is perhaps the original bracing pattern for plucked-stringed instruments, used on the predecessor to guitar, the lute. Luthiers also used it in the smaller Renaissance, Baroque, and early Romantic guitars. It is straightforward and is an excellent bracing pattern for guitars with lower string tension and creates a guitar with more prominent overtones than the bracing styles that followed it.
Perhaps the most famous luthier to use ladder bracing was René Lacôte, who used asymmetrical ladder bracing. His client list included names that will be familiar to any classical guitarist: Fernando Sor, Ferdinando Carulli, and Dionisio Aguado, and Napoléon Coste were all incredibly successful performers and composers whose music is still played today.
As a side-note, Ladder bracing was also used in steel-stringed Parlor guitars. The smaller body and shorter scale length of these guitars made ladder bracing a viable choice. The simplicity of construction allowed them to be mass-produced and sold in Sears & Roebuck catalogs, among others. These mass-produced guitars were affordable for those in difficult socio-economic situations. This affordability made them very prominent in the folk and blues music of the early 20th century.
Fan bracing looks like a hand-held fan, with the braces' tips very close together underneath the saddle and further apart at the tips near the bottom of the guitar. Fan bracing was used in early romantic guitars as early as 1759, primarily in Spain. In the 1840s, Antonio de Torres amalgamated many of the concepts common in early 19th century Spanish lutherie practice.
What were the features that were being developed at that time? The addition of a low sixth string on the early Romantic Guitar revealed one of its primary shortcomings; it had a weak bass response. The additional tension of the sixth string also created problems for the weaker ladder bracing. Torres combined a larger body with more robust fan bracing and created guitars that were so exceptional that they are considered the first modern guitar. Earlier in his career, he worked with the famous guitarist and teacher Julián Arcas. He remained at the top of his craft for his entire life; indeed, one of Arcas' most famous students played a Torres guitar his entire life: Francisco Tárrega.
Torres' fan-braced guitars had a much warmer tone than the guitars that preceded it, with stronger bass and broader dynamic range. Most classical guitar bracing innovations over the next 180 years were improvements or alterations on fan bracing. Here are some of the outstanding innovators who built on Torres's fan-bracing pattern.
Hermann Hauser built many different musical instruments, but his meetings and collaborations with two famous guitarists would seal his name in the history of luthiers. First, he met Tarrega's former pupil Miguel Llobet, an esteemed performer and arranger in his day and still known to serious classical guitarists worldwide. Later on, he would meet Andres Segovia, whose goal was to put the classical guitar in its rightful place: center stage of Carnegie Hall. To do this, Segovia required far more volume than contemporary guitars were able to produce. Through his collaboration with Llobet and Segovia, Hauser was introduced to fan bracing, which he used to significant effect. After sending Segovia several guitars and receiving feedback, he finally produced a guitar that met Segovia's approval in 1936. Segovia would play the guitar for almost four decades. That guitar currently sits in the Metropolitan Museum of Art.
He evolved the fan bracing by adding a transverse bar to create an asymmetrical design and using a longer scale to produce the volume that modern guitarists required. Segovia primarily used a Ramirez guitar in the final decades of his life.
Fleta refined the use of cedar as a soundboard material and used nine fan braces rather than the traditional 7. Similar to Ramirez, he used a transverse bar to create an asymmetrical design. His guitars were played by guitarists like Segovia, John Williams, and Alirio Diaz.
This bracing pattern is unlike any other. Its primary braces and tone-bars look like a rib-cage spreading across the lower bout of the guitar. This design was created by Michael Kasha, a scientist but not a musician, who was unimpressed with his son's guitar. Kasha's target was a bracing pattern that would allow 50% more of the string's energy to be converted into sound. He partnered with luthier Schneider; they worked together to develop the bracing pattern over three decades. While its supposed improvements are an enticing proposition, this bracing pattern never garnered much attention from high-level professions or luthiers.
While most bracing patterns are eponymously named, this one looks most similar to its name-sake; it looks just like a lattice. Or a waffle if you're not familiar with the term lattice. Developed by the Australian Greg Smallman, it is such a successful bracing system that it has led to an entire "Australian School" of guitar design. His guitars are played by fellow-Australian John Williams and (relatively) younger guitarists like Miloš Karadaglić. These guitars can be much brighter than fan-braced guitars. Smallman was one of the first luthiers to incorporate composite materials successfully; the lattice bracing is made using balsa wood laminated with carbon fiber. This bracing pattern is stable and strong, allowing for an incredibly thin top.
Double-Top or Composite Top Guitars
This construction technique is one of the most important guitar lutherie innovations of the past 40 years. Strictly speaking, this is not a bracing system. However, it does reinforce the top and serves much the same purpose as bracing patterns.
To make some of the first Double-Top guitars, Matthias Dammann and Gernot Wagner used very thin sheets and laminated a supporting structure between them. When finished, this composite soundboard will measure as little as 2.5mm thick! While the supportive middle layer was initially made of wood, Wagner and Dammann used Nomex by the mid-1990s.
What is Nomex? Nomex is a space-age material first developed by DuPont, the same company that gave us Nylon strings. Developed in the 1960s, it has a wide variety of uses; most uses are related to its fire-retardant properties. Honeycomb sheets are used in aircraft construction, and these are the sheets used by luthiers. Nomex is also used in fireproofing the clothing of firefighters and racecar drivers. It can also be used as acoustic material in concert halls or loudspeakers or.
When used in a composite guitar soundboard, Nomex provides strength and stability at a very lightweight (or, more specifically, a low density). That gives the guitar much more dynamic range. It seems that double-top guitars are becoming the preferred guitars among the world's elite performers: Jason Vieaux, Bill Kanengiser, Manuel Barrueco, David Russell, and Scott Tennant.
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