All About Top Woods

A guitar’s top is in no small part responsible for its tone. Acoustic Guitar explains the differences between the most common types.

In addition to the tremendous proliferation of guitar models offered in the past 20 years, there has been a dizzying increase in the number of wood species used by guitar manufacturers. Some of the more exotic names, such as Tasmanian blackwood and Carpathian spruce, were once the exclusive offerings of individual luthiers who essentially built custom guitars one at a time. But today, even large manufacturers like Martin and Taylor offer guitars made with woods that were completely unknown to the guitar community just a few years ago. The exotic hardwoods used to fashion the back and sides of a guitar are fairly easy to distinguish from one another—no one is going to mistake maple for rosewood, for example, or even bubinga for cocobolo. But when it comes to soundboard wood, the varieties are much more difficult to distinguish. Unless you are considering guitars made with mahogany or koa soundboards (see sidebar below “Mahogany and Koa Tops”), the trees that provide the wood for guitar tops are all conifers. Cedar and redwood tops can generally be distinguished from spruce, but there are at least four distinct species of spruce in wide use by guitar makers, and to a vast majority of guitar buyers, these spruces look very much alike. In compiling the information for this article, I talked with Dana Bourgeois, Bill Collings, George Lowden, Bob Taylor, Jeff Traugott, and other builders about their general impressions of top woods and the differences between them.

Spruce Rules

Spruce (genus Picea) is one of the most widespread coniferous evergreens on the planet, and over 35 distinct species are known. From Christmas trees to the Wright Brothers’ first aircraft, spruce has seen a wide range of uses, but as the soundboard, the principle voice of musical instruments, the wood has reached its highest calling. It doesn’t matter if you prefer Van Cliburn or Fats Waller, all those famous piano recordings and performances are examples of spruce soundboards at work. Even when strings are set in motion with a deceptively simple-looking horsehair-strung bow, and the soundboard itself is a delicately carved arch, the wood is still the same: from long before the time of Stradivari, virtually all bowed instruments from string basses to violins have been made with spruce tops. The reason for spruce’s dominance over other woods is due to a simple, but extremely important, mechanical property that was evidently discovered centuries ago by instrument makers of diverse cultures: spruce has an extremely high strength-to-weight ratio, a property that both Stradivari and the Wright Brothers put to good use.

Unlike the violin family, however, the guitar’s size and shape, along with almost everything else about the instrument, varies dramatically. If you make a violin significantly larger and give it a longer string scale, it’s tuned a fifth lower and becomes a viola. But a 17-inch jumbo guitar and a parlor model barely over half that size are usually tuned to the same pitch. This is because the steel-string acoustic guitar, unlike the highly codified violin, is essentially a folk instrument, one barely 100 years old. Yet despite the incredible range of shapes and sizes, the woods preferred for making guitar soundboards are remarkably consistent. Although cedar, and, to a lesser extent, redwood, have been used for the soundboards of high-grade acoustic guitars for many years, spruce has been the overwhelming favorite, especially for instruments strung with steel strings. Although opinions vary regarding the fine points in any comparison of top woods, all guitar makers agree that different species of spruce that often look very much alike can have different tonal characteristics.

Spruce Woods

Sitka spruce (Picea sitchensis) has ruled the North American steel-string guitar market since shortly after the end of World War II. Sitka is the largest tree in the spruce family, and it grows along the Pacific Coast from Alaska to northern California. Sitka is known for its strength and toughness, ideal qualities for the soundboard of steel-string guitars that often must endure both rough handling and aggressive playing.

Adirondack spruce (Picea rubens), which is often called Appalachian or red spruce, comes from the Adirondack mountains and Appa­lachian region, on the opposite side of the continent from where Sitka spruce is found. It grows from eastern Quebec to Nova Scotia, and from the uppermost reaches of New England to North Carolina. This was the spruce species used by both Martin and Gibson during the prewar era, and it is probably the reputation of those guitars alone that prompted its return to the market in the early 1990s as “reissue mania” set in. Adirondack spruce trees are much smaller than Sitka, and the forests where they grow have been under more pressure from development and logging, while acid rain has also taken a toll.

Engelmann spruce (Picea engelmannii) is another spruce from western North America, but unlike Sitka it is rarely found at lower altitudes. Engelmann grows in British Columbia and southwest Alberta down into Washington and Oregon, and as far south as Arizona and New Mexico. The trees are much smaller in diameter than Sitka and grow more slowly since they are found at higher altitudes. Engel­mann spruce is generally softer than Sitka.

European spruce (Picea abies or excelsa, an older term for the same species), commonly called German spruce, comes from a wide area in Europe ranging from Norway to Italy and east into the Carpathian Mountains around the Black Sea. Historically, much of this wood has come from wood dealers in Germany, so it has long been known as German spruce even though the actual trees the wood came from didn’t grow in Germany. When you read the names of the countries this spruce can come from, it seems hard to believe they are all the same species. What could a spruce guitar top from a tree in Norway, for instance, have in common with Italian spruce? However, when you look at a world map, it’s obvious that a similar distribution pattern exists in the wide growing range of North American spruces. Engelmann spruce might come from British Columbia or Arizona, but it’s still Engelmann. Adirondack spruce could be from a tree that grew in Nova Scotia, New Hampshire, or West Virginia.

Cedar and Redwood

Western red cedar (Thuja plicata) is another widespread conifer from the Pacific North­west, ranging from southern Alaska to northern California and as far east as western Montana. The trees rival Sitka spruce in size. Despite the name, it’s not a true cedar at all, but instead falls within the cypress family. It has been a favorite top wood for classical guitars for many decades, but in recent years has also been used for steel-string guitars. Northern Ireland’s George Lowden was one of the first builders to rely heavily on cedar tops in developing his signature sound in the 1970s, and this in turn helped popularize its use by other guitar manufacturers. “I decided by feel that I should leave it reasonably thick and not too light, and with hindsight that has turned out to be exactly right,” Lowden says. This observation points out one of the critical diffi­culties when comparing top woods, namely that their different levels of stiffness often require significantly different thicknesses in order to get optimum tone for a given guitar shape and/or gauge of strings. Although cedar can usually be recognized by its warm brown color, as opposed to the lighter and more yellow color of spruce, some cedar tops are such a light brown that they are almost indistinguishable from darker versions of Sitka spruce. Cedar is softer and more fragile than the spruces used for guitar building, so it needs more careful handling, both by the luthier and the player.

Redwood used in guitar making is usually Pacific coastal redwood (Sequoioideae), trees that can dwarf even the largest Sitka spruces. Redwood looks and sounds more like cedar than spruce, although it is generally stronger than cedar. One quality redwood shares with cedar, which limits their use in guitar making, is that both are more prone to cross-grain breaks when dropped or damaged by a sharp blow. Cracks in a soundboard that follow the grain are relatively easy to repair, but cracks across the grain are more unsightly and can weaken a top so dramatically that it cannot be repaired.

Woody Sounds

But what do these top woods sound like? When you pose this question to most guitar makers, their first response is, “Compared to what?” As Bob Taylor points out, you cannot talk about the sound of one wood species without comparing it to another. “Since over 90 percent of the steel-string acoustic guitars in North America have Sitka spruce tops,” Taylor says, “that’s our most logical frame of reference.” Other guitar makers I spoke with agreed, so for the rest of this discussion, Sitka spruce will be the baseline. And while other top woods get more press today, luthiers generally agree that Sitka is underrated simply because it has been so widely available and comparatively inexpensive. While it may not be the optimum soundboard material for certain styles of playing, it is highly versatile. Bill Collings, for instance, calls Sitka “the do-everything spruce.”

Engelmann spruce is often described as softer and warmer when compared to Sitka spruce. It’s lighter in both weight and color and responds well to a light touch. The trade-off, however, is that Engelmann is more easily overpowered by a strong player. Collings feels this wood is “best on smaller guitars with less (string) tension,” but it’s not unusual to find it used on larger guitars as well. Anyone who works in guitar repair would probably add that Engelmann isn’t nearly as tough as Sitka, so it’s more easily damaged.

Every builder I spoke with had nothing but praise for Adirondack spruce. Collings kept stressing its strength, especially with the grain (from one end of a guitar top to the other), while others stressed its higher elasticity, or as Taylor called it, Adirondack’s “springy” quality. Bourgeois referred to its “high velocity of sound,” which he says usually results in a guitar with a lot of “headroom,” meaning an expansive dynamic range. But Adirondack is more than just good at being loud; it has a wide tonal range as well. It’s therefore not surprising that though Adirondack’s most loyal fans are flatpickers, fingerstyle players like Laurence Juber (who has requested Adirondack spruce for the tops of all his Martin signature models) also give it high marks. The only downside to this spruce is its cost, the combined result of current high demand while much of its original growing range has fallen to urban expansion. Because there is less Adirondack spruce to choose from, the tops often show more variation in grain and color.

Of all the spruces, the widest range of opinions I gathered was for European (“German”) spruce. This is probably because of the wide geographical territory from which it is harvested (some wood brokers in Europe have been selling instrument-grade spruce for decades and are understandably protective when asked about their sources). Jeff Traugott says he uses German spruce “for clarity and brightness” as well as its “very even grain with less striping.” He points out that “it has a clean look that complements the overall design of my guitars,” admitting that aesthetics are part of his decision to use it on a vast majority of his instruments. While other guitar makers, Taylor among them, find the tone of European spruce to be very close to that of Engelmann, both Collings and Bourgeois find it has extra brightness in the overtones. In short, everyone agrees that European spruce sounds different from Sitka, but descriptions of what that difference sounds like are varied.

When it comes to western red cedar, however, guitar builders are generally in agreement, often saying that cedar has “less headroom” or that it “tops out more easily.” Cedar gets high marks for fingerstyle guitars, used by players with a lighter touch, because it responds quickly and delivers lots of overtones even at low volume. It’s harder to get opinions on redwood, primarily because not many builders use it, but the brittle, easy-to-crack nature of both cedar and redwood is almost always mentioned. Once you get beyond the more traditional guitar designs, however, top woods like cedar and redwood have a wider following. The extra sustain of redwood has been put to good use by McPherson and other builders with complex top-bracing patterns.

Construction and Design Matter

How a guitar sounds, of course, depends on a wide variety of factors, including the body size and shape, wood used for the back and sides, bridge type, internal bracing, and graduation of the soundboard itself. All the luthiers I interviewed agreed that the species of tonewood chosen for the top is one small factor in the overall sound of a guitar. As Taylor put it, “The whole guitar is like a recipe, and changing the top wood is merely changing the seasoning.” Guitarists familiar with different woods and their characteristics are prone to making sweeping generalizations about tone and volume, but they are often comparing instruments with a long list of other differences. Even when the body shape is essentially the same, the structural design of the sound chamber and how it is put together is rarely the same from one maker to another. A slight difference in the radius of the guitar’s top, for example, or the position of the X-brace in relation to the bridge, could easily have more impact on the instrument’s tone and volume than whether it has a western red cedar or Engelmann spruce soundboard.

Nowhere are these differences in design, from fundamental to subtle, more apparent than when comparing examples of the quintessential big American guitar, the dreadnought. It’s easy to find many examples from different makers, all made with Sitka spruce tops and East Indian rosewood back and sides. A Taylor 810, or its cousin the DN8, sound dramatically different from Martin’s D-28 and HD-28. Likewise, two dreadnoughts made of the same woods by Collings and the Santa Cruz Guitar Company will have distinctly different voices. The significant tonal differences are determined by the overall design of each instrument, not just the woods used to build them. Guitars are as different as the personalities of the people who design them, and in an increasingly depersonalized, high-tech world, that’s somehow comforting. As one guitar maker with over 30 years experience put it: “If you need a guitar that sounds different, don’t bother getting the same thing with another type of top on it, just get a different guitar.”

Sidebar:
MAHOGANY AND KOA TOPS

Although conifers like spruce and cedar have ruled the soundboard market seemingly forever, guitars are one of the rare stringed instruments where there is a tradition of hardwood tops as well. It all started with Hawaiian guitars (and ukuleles) about 100 years ago, where backs, sides, and tops of Hawaiian koa were common. Those guitars, of course, were played with a slide (much like a modern-day dobro), and for the long sustain of smooth but whiny tones, a dense hardwood top like koa made perfect sense. When Hawaiian music styles jumped to the mainland, guitar manufacturers in the states began making Hawaiian guitars out of mahogany as well. Soon those same mahogany- or koa-topped instruments were being fretted, instead of played with a slide, and they’ve been with us ever since. Because of the superior durability of mahogany soundboards, the edges didn’t need binding, or much finish, allowing all-mahogany guitars to be sold at lower prices. Big guitar factories in Chicago also made lots of inexpensive guitars out of birch, including all those adorable cowboy-stencil models.

Modern guitars with hardwood tops are no longer cheapos, but still have a darker, colder tone that Bob Taylor describes as “typically lo-fi, great for strumming and blues, but no church bell tones.”

This doesn’t mean that guitars with mahogany or koa tops don’t have dedicated fans, typically players who like the pronounced midrange response and strong fundamentals that a stiff, dense (and comparatively heavy) soundboard produces. Such soundboards are certainly a lot less fragile than spruce, which is probably why Martin advertised its first all-mahogany guitar model, in the early 1920s, as “handy for general knock-about use.”