Shapes of Taylor Guitars

Bob Taylor’s shape-shifting experimentation as a young luthier led to refinements in traditional guitar shapes, such as the Dreadnought and Jumbo, and to the development of new shapes, like the Grand Auditorium and Grand Symphony. While each Taylor shape has created a niche for certain playing applications, they all share Taylor’s signature tonal traits of balance and clarity.

Body Outline
The outline of a guitar’s shape defines how big the top plate, or soundboard, is, and how much the tapering of the waist will cut into it. A Taylor Dreadnought, for example, tends to have a broader waist, whereas other Taylor shapes, by comparison, have fairly narrow-waists. The narrower the waist, the more it tends to impinge on the soundboard’s tonal output.

Body Depth
A guitar’s body depth, or overall thickness, is usually tapered from the lower to upper bout. A deeper body can add a certain degree of bass to a guitar’s tone, but it doesn’t necessarily yield a lot of volume or a deep, rumbling bass tone. This distinction highlights two different elements of acoustic tone, as Bob Taylor explains.

“There’s bass tone that comes from the top, and then what I’ll call ‘cigar box’ tone,” Bob elaborates. “Any hollow box with a bridge and strings on it will give you a certain whoosh — it’s just the air volume, kind of the breath of the guitar. You can change the breath of the guitar by changing the body depth. But that doesn’t change the ‘vocal cord’ of the guitar, the real fundamental part, the thing that’s really vibrating, which is the top. So there’s a marriage between that breathy part and the vibrating, fundamental vocal cord part. It’s like the human voice: It’s got the vocal cords that are vibrating, and it’s supported by the box and the air behind it.”

Arch
A slight arch is built into the top of most acoustic guitars to help control the distribution of tension and to influence the tone. While the back arch on many brands of acoustic guitars tends to be fairly standardized among acoustic builders, top arches tend to vary a bit. Despite the common reference to acoustic guitars as flattops, not many modern acoustics are truly flat. A real flat top often sounds great, Bob Taylor says, but tends to distort and look funny under light.

“Most people want to know that their guitar will look good and last for a long time,” Bob says. “So, most big factories put an arch in their guitars because it’s a string geometry that makes the top strong. It also tends to make the guitar more modern-sounding — clear and bright — but it also holds the tension and keeps the top generally smooth.”

The top arch also interacts with the bracing and the string tension to create a certain desired geometry. “We might put a lot more curve than we want on the front part of an X brace and less curve than we want on the back part,” Bob explains. “When you apply string tension, the bridge torques, pushes out some of the curve on the front of it, pulls some curve into the back of it, and the net result is the geometry you wanted on the top.”

Neck Angle
The neck angle, bridge height and the overall alignment in relation to the body are designed to enable the guitar to support the string tension and perform well under different weather and action conditions. But even if the arch in the top and the balance of tension are perfect, Bob says, a neck angle with improper geometry can negate everything.

“There’s essentially a launching pad for the fretboard that rises out of all of this top geometry,” he explains. “Think of the bridge as the pitcher’s mound and the area where the neck sits as home plate. Home plate is aiming at the pitcher’s mound, but the baseline — the outline of the body — is doing its own thing, too. So, there’s this nice little rise here at the bridge. There’s a ramp that rises out of this whole spherical balloon surface that comes up into there, and when the neck goes on, it has to be just right. This is where we have a Ph.D. in neck playability, because the NT neck is our crowning achievement in terms of getting that alignment perfect every time. And if it’s not dead nuts, you put in a different set of angle spacers and it is. Not getting that right is like building a car without alignment. You’ve built everything else right, but one tire is going this way, and one’s going that way. Why not make it to where you can get them properly aligned? That’s where it all comes home and determines whether that guitar plays well.”