Whether you are a budding guitarist planning to buy your first acoustic guitar, or a more advanced musician who already owns one, there is a question that has been often overlooked by even some of the most respected players: should acoustic guitar tops be flat?
This line of inquiry is not surprising at all since steel-stringed acoustic guitars are commonly referred to as flat tops, even though these instruments are not limited to such shape and form. A vast majority of acoustic guitars today are flat due to the fact that it is a design that contributes to an instrument’s functionality and sound quality. Therefore, this design was adopted by luthiers and guitar companies as the standard in crafting acoustic guitars.
A guitar’s top, together with the sound box and a soundhole, helps one another in producing resonance in an unplugged setting. This structural design also provides more top strength to ease the strain that your instrument’s bridge might endure from a set of steel strings. This does not mean however that the curvature on archtop guitars is a flawed design, it’s just that they have sound attributes that are different from one another and it all boils down on the musician’s preferences.
The shape and form of the instruments that we play today go deeper than just the overall aesthetics that they possess. Stability and tone is largely affected by a guitar’s top, and as a result, a near-perfect version of this gut-strung instrument has led to the further evolution of contemporary music.
By the 1960’s, the brighter sound of acoustic steel guitars became a fixture in blues, country, folk and even rock n’ roll, giving birth to a more stripped-down set up that is a total departure from the big bands of the 40’s and 50’s, and the massive orchestras of the classical era.
Should the top of an acoustic guitar be flat?
Although there is no written rule against acoustic guitars that are fully archtop, flat tops are the norm. A slightly convex top is more common in semi-acoustic or hollow body guitars that we often see in the hands of jazz icons such as Joe Pass and Wes Montgomery. Electric guitars such as the Gibson Les Paul usually come with an arched top, while Fender Telecasters have flat tops.
Unlike steel-stringed acoustic and nylon-stringed classical guitars, hollow body guitars have much larger bodies with f-holes that were inspired by violins and cellos. These workhorses are essentially electric instruments that don’t sound as loud and vibrant as flat top guitars, but will easily rip through bigger ensembles when plugged into an amplifier.
However, if you own a flat top acoustic and the guitar’s top is now either sunken or going through what they dub as a “belly bulge,” then we are treading a different path here, as your instrument might have warped as a result of various factors.
What is warping and what causes it?
Even high-quality acoustic guitars can experience warping especially in the bridge area where an abundant amount of stress is concentrated. Because wood is not as malleable or flexible as rubber, it is expected that after prolonged periods of usage, some parts of a guitar could deteriorate or become deformed due to the constant strain that it is receiving. Warping can also happen to a guitar’s neck when the truss rod bends to an incorrect angle, largely affecting the playability of the instrument.
While no guitar is safe from bulging, the ones made out of cheaper, weaker materials are more prone to deformation. String tension can make the top bulge, and on the other hand, it could become recessed as well. Harsh weather conditions such as extreme heat, could weaken the glue that binds the parts of a guitar, including the bridge and this could cause a belly bulge, along with other issues. Keeping acoustic guitar tops flat can be tricky. A sudden change in temperature can also be detrimental to a guitar, making it a common predicament for touring musicians.
Warping can definitely affect the sound of your guitar. Some guitarists are led to believe that the bulging top can augment the loudness of an instrument. If this is true at all, then guitar companies should just stick to the bulging top design, but that is not the case and that is why luthiers and manufacturers follow specific standards when building their products.
How to solve your flat top guitar’s warping issue
Use a lighter gauge of string
Shifting to a different string gauge may affect your playing and the tone that you are after, but if your flat top is having a hard time with the tension, then a change in string choice is necessary to prolong the life of your instrument.
Store your guitar properly
Taking care of your guitar will ensure that it will perform well for many years. Storing them properly is one of the most important factors to consider to promote better guitar health. Not using a guitar stand or a hard case could increase the strain on your beloved acoustic and will definitely be a huge headache once problems such as belly bulging starts to manifest.
Humidity is also one of the main factors that causes bulging or warping on a guitar. It would be best to keep your instrument at room temperature with a 45-55% relative humidity. If that is not possible, small packs of silica gel will help reduce the humidity inside your guitar case.
Seek Professional Help
Guitars are sensitive creatures and whatever problems they are undergoing requires the help of a skilled luthier. Never try to solve warping and other issues on your own as it could only lead to more complications. Are acoustic guitar tops flat? Not if you have a bad warping issue. Always seek the services of a pro to make sure that your steel-string acoustic guitar tops remain flat.