Acoustic Guitar Construction

Acoustic Guitar Diagram

When studying acoustic guitar construction, you quickly learn two things. First, there is no single "right" way to build an acoustic guitar (though there are plenty of wrong ways). As an example, Bob Taylor (of Taylor guitars) chose to use a bolt-on neck to facilitate neck resets. People thought he was crazy to add this to acoustic guitar construction, but after many years, Taylor is one of the most respected names in the business.

Second, there are many components of an acoustic guitar's construction that drastically affect the tone and playability, some more than others. With an acoustic guitar, for example, the top wood is incredibly important. Also, the type of neck construction can affect the feel and playability. 

With all this in mind, let's take a look at some principles of construction that will help you understand how acoustic guitars are literally "put together."

Body Styles

One of the most important decisions a luthier (someone who builds guitars) must make is what type of body style they wish to use when constructing the guitar. And often, the body style is dictated by its eventual use. If someone is building a guitar for a bluegrass player, for example, then chances are the builder will choose a "dreadnought" shape (see below). This decision is the first to affect the guitar's overall tone and volume as well as its playability.

The Dreadnought

Perhaps the most common body style is the "Dreadnought" guitar (named after the warship and introduced by famed builder Martin guitars) which is known for its deep sound and pronounced bass response. Popular with bluegrass pickers and rock and rollers alike, the Dreadnought shape has been widely copied since its inception.

Other Styles

There are other body styles, each of which has its strengths and weakness. The Grand Concert style (also called a 00) is small overall and relatively thin, so it's comfortable for many to hold and play, though its sound is necessarily quieter. Another style is the Grand Auditorium, which is an increasingly popular body shape and construction due to its versatility. The Taylor x14 series (including their very popular 814CE) use this style to great success. As its name suggests, the Jumbo style is the largest construction type. Essentially an enlarged Grand Auditorium style, the Jumbo produces a large sound but is more difficult to play for many due to its size.

Wood

In addition to body style, the type of wood used has a dramatic impact on an acoustic guitar's timbre. An acoustic guitar has various tonewoods used in construction that all affect the guitar's timbre. For example, a guitar with a maple top will have a brighter, "zippier" tone than a guitar with a cedar top, which is known for its warm, round tone popular with fingerstyle players. So, when choosing an acoustic guitar, knowing the effect wood can have on the tone is crucial.

String Tension

Another significant component of acoustic guitar construction (as opposed to, say, traditional classical guitar construction) is the accommodation of the higher string tensions. Since classical guitars use nylon strings, the tension is much lower than that of steel string guitars. Steel string accoustics must be internally reinforced to handle the increased tension, which is accomplished through two primary construction components: stronger bracing and an internal truss rod.

Internal Bracing

A guitar's bracing is a series of wooden supports in the inside of an acoustic that provide stability to both the top and back of the guitar. The challenge faced by the luthier is that this support needs to provide structural support without impeding the guitar's tone. There are many styles of bracing preferred by luthiers for their tonal and durability, many of which are named for their appearance (e.g. X-bracing, A-bracing, Ladder Bracing). The X-bracing developed by C.F. Martin remains one of the most popular bracing styles still in use.

The Truss Rod

In addition to stronger bracing, steel string guitars now all contain an adjustable steel rod inside the neck known as a "truss rod," which helps compensate for changes that alter the neck such as temperature and humidity. Furthermore, the truss rod adds extra strength to compensate for the tension of steel strings.

Pickups

Finally, many acoustic guitars include onboard pickup systems to facilitate amplification. These may be internal microphones or, more often, pickups embedded under the saddle. Sometimes, a combination of internal microphones and saddle pickups are used. Moreover, oftentimes onboard preamps are installed, though many players prefer the preamps to be external in order to eliminate excessive cutting of the wood.

Acoustic Guitar Construction - Final Thoughts

As you can see, making a functional, beautiful, yet highly playable acoustic guitar is a complex yet beautiful amalgam of many different components that, when assembled properly, yields a quality instrument.