“FREE THE SOUNDBOARD” expresses our aspiration to open up the possibilities of what the acoustic guitar can become.   

Traditional acoustic guitar design continues to express the goal "To build a guitar with the lightest possible soundboard without having the guitar implode due to the tension of the guitar strings.”     

Structural considerations have to come before tonal objectives in any design where the played strings rely upon the soundboard to maintain tension. 

The TurboTail eliminates this need by removing the string tension from the bridge and moving it to the tail block.

The TurboTail is a simple, elegant device that diverts the tension of the guitar strings from the soundboard to the structural tail block of the guitar. All of the vibrations of the guitar strings are still transferred directly to the soundboard to produce sound. But the tension load is diverted to the tail block, leaving the delicate soundboard free to vibrate optimally.

The result is that the guitar soundboard can do what it was intended to: Amplify and temper the vibrations of the guitar strings without having to provide a structural anchor for the strings.

Guitar soundboards without the TurboTail act as structural members, like a floor, a wall, or a steel beam. This means that the soundboard’s most important job is to avoid collapsing due to the intense stress exerted by the taut guitar strings. 

Guitar strings are like steel cables. The total tension of six steel guitar strings ranges between 140 and 190 pounds, depending upon the string gauge (12-string guitar tension can exceed 250 pounds.) That’s enough tension to lift a full-grown man off the ground. Imagine what your guitar could sound like if the soundboard didn’t have to do all this heavy lifting.

Expert luthiers admit that the current design of the acoustic guitar is terribly inefficient. It is estimated that only about 5 percent of the energy produced by the picked, or strummed, strings actually arrives at our ears in the form of sound. Ninety-five percent of the vibrations is consumed as heat friction - is absorbed into the wood of the guitar - or even the player’s body.   

Thus, any improvement in efficiency is great for guitars. A more efficient guitar produces more sound for the same amount of effort. In fact, a more efficient guitar can even be smaller, which means that it’s more comfortable to play, as well as being lighter and  more portable. A more efficient guitar can use lighter gauge strings to produce the same volume of sound. Lighter strings are easier on the fingers. Plus, lighter strings are easier for bending notes, performing hammer-ons, pull-offs, or fretting difficult chord shapes.

Skilled guitar builders benefit from installing the TurboTail on their custom guitars because It allows them to lighten the soundboard far beyond what has ever been possible. 

With TurboTail, every guitar builder can approach soundboard construction as a purely sonic issue. The builder is no longer required to design the soundboard to handle structural loads first and only then design for the desired tone or “voice.”

This means that instead of installing “top bracing” to handle structural loads before installing “tone bars” to optimize tone, the installation of top bracing can be skipped altogether.

The key is that with the TurboTail a luthier is free to create a guitar in whichever way he or she desires, without the need to compensate for structural load as an over-riding concern.

For a fuller explanation, read our blog post: Can the TurboTail Impact Guitar Building?

The TurboTail can benefit any acoustic guitar. Of course, the most dramatic results are achieved when you install a TurboTail on a lightly braced guitar. These really open up. The TurboTail adds projection, bass and sustain, as well as note separation and clarity.

If your guitar is built like a fortress, the results are more subtle. However, sustain, note clarity, as well as bass response have been improved on every guitar that we've tested.

Yes, it’s true! With the TurboTail, even a very lightly built guitar with a feather-light soundboard can withstand the tension force of the heaviest gauge steel strings for decades. This even includes Classical guitars.

With the TurboTail, you can install steel strings on any classical guitar that has a truss rod in the neck. (All Cordoba and Godin guitars have truss rods.) The truss rod helps to stabilize the neck, as well as making it possible to adjust the string action.

To find out more read our post on steel strings on a classical guitar.

When the tension of the strings is diverted from the soundboard to the tail block, the risk that the guitar will experience any temporary or permanent deformation of the soundboard or lifting of the bridge (“bridge belly”) is eliminated. 

Even better, any past soundboard deformation or bridge lifting can be corrected by installing the TurboTail on a guitar with a warped soundboard. When you install the TurboTail on a guitar with a warped soundboard and a lifting bridge, you will see an immediate improvement. The bridge will be held tight to the soundboard, the way it was when the guitar was purchased. The soundboard will be closer to the shape that it was designed to have. Over time, the soundboard will return to the shape it had the day it left the shop.   

With no tension on the soundboard, it is conceivable that acoustic guitars could last for centuries. 

Archtop guitars are different from flattop, steel-string guitars in several ways. First of all, as the name implies, the soundboard of archtop guitars is an arched or domed shape. Just as the arch of a bridge or the arched roof of a sports stadium gives strength to help support these spans, the arched top of the guitar stiffens the top. As well as being stronger, a stiffer top means that an archtop has less resonance (“sustain”) than a flat-top guitar. The notes of an archtop are short and percussive compared with a flattop acoustic guitar.  Notes can be quite loud, but they don’t linger much. Thus, the archtop is said to have a lot of “attack” but little “sustain."  

By contrast, flat-top guitars are quite resonant, with a lot of sustain. Since flattop guitars have less attack compared with sustain, the individual notes are subordinate to the overall tone. The notes blend more, so the sound is mellower. Flattop guitars are well suited to notes combined into chords (of course, lead lines are also possible), as opposed to archtops where individual notes are more distinct.        

The bridges of archtop guitars and flattop guitars are also quite different. The bridge of a flattop guitar is a thin piece of wood that sits low on the soundboard and is securely glued in place. The guitar strings run parallel to the soundboard maintaining the same approximate height from the soundboard before they are anchored to the bridge. Almost all of the string tension is applied parallel to the soundboard. The force exerted by the vibrating strings is nearly equal,  both downwards and upwards.   

This form of attachment causes the bridge and the soundboard to move in unison. When the strings are played, the guitar bridge moves. Wherever the bridge goes, the top of the guitar follows, as if the bridge and the soundboard were one piece. There is also a slight rotational or torque force exerted by the strings as they descend from the bridge saddle to their anchor pins (or holes in the case of pinless bridges).  However, relative to the archtop bridge, this transverse pull is insignificant.    

The bridge of an archtop, by contrast, is quite tall. Usually, the archtop bridge is not glued to the soundboard.  It is a separate structure,  like a small tower or wall (or a real structural bridge).  This is known as a “floating bridge.”  Due to the bridge's height and the soundboard's stiffness, the archtop bridge is “squeezed” in place between the strings and the soundboard. The coupling between the strings and the bridge is a result of the heavy downward pressure that the strings exert upon the bridge. In turn, the bridge exerts this same downward pressure upon the domed top of the guitar. The structural dome of the archtop, in turn, resists this downward pressure.  

Because of the height of the archtop bridge, when a string is plucked, much of the force exerted is vertical, perpendicular to the soundboard (There may be 40 lbs of downward force or more on the guitar soundboard). This constant downward force, combined with the added velocity of the plucked strings, exaggerates the impression of a percussive, drum-like quality to the notes of an archtop guitar. The characteristic  “thunk” sound of an archtop is strongest when the string descends to the bottom of its downward trajectory. The same is true of standup bases. The sound lets off dramatically as the string reverses direction and heads back up.

The TurboTail is ideally suited to flattop acoustic guitars because it enhances their qualities of volume, resonance, and sustain, qualities which are prized in fine acoustic guitars. Because the strings of a flattop guitar are low and run directly parallel to the soundboard, extending the string tension to the TurboTail, mounted on the tailblock of the guitar, is sympathetic to the nature of the instrument. There is no need to redesign or alter the instrument in any way. The relationship between the bridge and the soundboard is unaltered, and optimal coupling is preserved. The bridge and soundboard continue to move in unison.