Regarding Solid Body Stringed Instruments…

Addressing Sound Production and Dead Spots:

 

Since the first Carbon-Graphite neck beams were produced there has been much discussion about the ability of carbon fiber-structured necks to diminish or eliminate the less attenuated or harmonically incomplete notes known as deadspots. These more commonly occur on wood-necked stringed instruments. The claim that carbon fiber-based necks eliminate all deadspots in all cases was most-widely made by Modulus Guitars. Even though it is generally the case, such a comprehensive claim has never been made by Moses Carbon Graphite USA for reasons that actually apply to all carbon graphite necks. 

 

Whereas, carbon graphite necks do have the ability to eliminate deadspots, this generalized and comprehensive statement was and remains untrue in various cases. This is due to the actual and real complexity of stringed instrument materials, material relationships and construction. In a stringed musical instrument, all materials between the nut and the bridge saddles contribute to the movement of string-activated sonic information.  In some cases material composition and embodiment even beyond this area effect attack, sustain and decay along with the note’s frequency content as the note plays-out. 

 

When a carbon graphite neck beam is properly produced, and is continuous between the nut and the bridge as with a neck-though-body beam, the producer of the beam has complete control over all material composition between these points. In this case the manufacturer ‘designs’ the entire active beam, thus dictating all aspects of outcome with respect to a note’s tone, development and attenuation. And in this case, a properly engineered and well-constructed carbon graphite neck-through-body beam can be manufactured to effectively eliminate all deadspots. Conversely, when the neck beam is not continuous from nut to bridge, the design engineer looses complete control of the outcome due to the introduction of other variables, especially within the vibrating string length system. Neck and body discontinuity, known as de-coupling, results from use of a bolt-on neck beam and leaves the neck as but one major yet ‘separated’ element amongst a group of nut-to-bridge parts. 

 

As general background, it is important to note that carbon fiber is used in various embodiments to produce neck beams. Basically, not all carbon fiber-structured necks are made in the same way, nor with the same set of materials. Including and in addition to the disparate physical embodiments, and due to the differences between bolt-on and neck through beam styles, there are a number of other elements, all working in combination. These elements interact with each other to produce a complex variety of results. Individual elements and element combinations that effect outcome include:

 

1) Relative density of each element. For instance, neck beams or bodies may have a density or combination of densities which produce a resonant frequency or a group of frequencies that absorb energy, thus producing overall attentuation and cancellations.

 

2) Separate neck and body beams may each have discrete overall densities which combine together with varying degrees of success relative to ‘even’ and complete transmission of energy between the nut and bridge. A wood or carbon graphite neck beam may tend to work very well in most cases with a specific body material type. However, even another piece of wood from the same tree may react differently when mounted on the same body after becoming a finished body. Specifically and by example, acoustic luthiers pride themselves on their selection of specific pieces of particular woods in order to achieve their perceived best result. Often players of electric stringed instruments simply purchase their instrument with limited review or without any examination of even the surface of the body material, let alone its interior quantities. If they even know what the wood’s species is, they may be assuming that all pieces of a perceived good specie are the same and good for its application. This is not simply true. Specifically, when water is scarce, a tree grows more slowly (as exhibited in its yearly growth rings), making the wood very dense relative to its particular norm and resulting in a different composition of elements than during the wet periods. The dark ‘rings’ are the dense slow growth periods, while the fat light regions are formed during the fast growth periods. The knots where tree limbs formed also have different characteristics in both composition and density . The bottom line is that within one wood log there are sections which have different percentages of each element. 

 

This variation in composition means that not all sections of a specific  wood beam will exhibit the same characteristics:

a) Woods have disparate densities within and between their major fibrous grain and other cellulousic material.

b) Woods have various and varying distribution, orientation and density of fibrous grain.

c) The ‘actual’ overall density and ‘distribution of densities’ within a particular piece of wood often varies from ‘Textbook’ for that Species. These characteristics also vary greatly within adjoining areas of each piece of wood. Thus it can only be accurately stated that a particular wood has a ‘tendency’ to provide a specific outcome. A piece of wood is generally chosen by looking at the surface, tap-tone testing, choosing a specific orientation for its use, etc. The piece is tooled to remove material in order to achieve the target dimensions. This process, taking away material that you don’t want until what remains is what you do want, is ‘subtractive’. With good fortune it’s contribution to the instrument will be what is desired. In contrast, the production of a carbon graphite neck beam is ‘additive’. Carbon fiber-structured necks are not made from a solid lump of stuff, but contain a engineered structure that is ‘designed’ to produce specific outcomes. The design engineer chooses a group of materials which when combined, produce a calculated result. In the carbon fiber-structured neck beam case, the designer has much greater control over the outcome. This is the result of purposeful choices made which are based on study of the complex relationships of selected composite materials. 

 

Other key elements effecting outcome include:

1) The material composition of a headstock. Some absorb energy while others do not. When headless necks were introduced, its exclusion removed this variable from the equation while shifting nodes to new locations along the beam.

2) As stated above, neck through body beams, which are continuous from nut to bridge, maintain relative continuity of materials between these key points. A wood neck through beam may still contain unpredictable variables within. In contrast, an engineered carbon graphite neck-through-beam can be designed and constructed to minimize or eliminate the unknown internal variables inherent with wood. Thus, the outcome becomes far more predictable. However, when a wood or carbon fiber-structured neck beam is bolted onto a separate body, this introduces a notable discontinuity where the neck heel sets against the body in the heel pocket. Even though an installer may firmly mount the neck so that string tension is fully held, there is ‘no’ mating of the adjoining surfaces on a molecular level. In essence, two surfaces pushed against each other still have microscopic (and larger) gaps between adjoining surfaces. These spaces are barriers to complete transfer of energy. In many cases, the energy transfer when compared to continuous beams may be circa 50%. Sadowsky Guitars and others have taken to applying an Epoxy coating to the neck’s heel, with the bolt-on neck isolated from the body pocket with an intermediate and temporary separation layer of Saran Wrap or mold release. This is an attempt to produce a body pocket surface that more closely reflects the shape of and mates to the bottom of that removable neck’s heel. It should be noted that energy lost as it attempts to cross discontinuities is not all of the same frequency or the same group of frequencies, nor is there the necessarily the same amount of attentuation across the frequencies included. So at ‘each point’ of discontinuity, the relationship of frequencies that continue to travel through the neck/body system changes. This dynamic of change is occurring multiple times between the nut and the bridge ( and beyond) for each note generated; ‘A’ becomes ‘A +/- B’; ‘A +/- B’ becomes ‘{A +/- B} +/- C’, etc. With woods it is well-known that close, tight and continuous strand fiber is required to produce the optimum structural and tonal results. In its own way, the same is true with carbon fiber. When both wood and carbon graphite necks are bolt-on mounted, the continuous strand embodiment and thus the material continuity between the beam and the body is severed. As a notable aside, neck-through-body beams contribute greater sustain relative to attack than do bolt-on beams.

 

3) A mounted nut’s mating to the surfaces of the nut slot as well as the degree to which the string mates with the individual nut string slots has a similar influence as that discussed in #2. As pertains to the strings mating, simply imagine the amount of surface contact that can be lost when a string does not sit so that the bottom and sides are completely in contact with the nut slot walls. And to a degree, the kind of isolation of a vibrating roundwound string, which has less string surface touching the nut slot walls, produces different results than a flat wound string having more material actually touching the nut slot surfaces. However, there are overall a much greater set of dynamics at play as a string is pressed against the fingerboard by flesh or a capo at positions along the neck, the dynamics of a string vibrating in atmosphere above the board, material composition, string dimensions, mass and other factors.

 

4) Cancellation through the bridge and nut to the neck beam and body (or potentially even an increase in amplitude) when one string remains vibrating as another string is activated is yet another factor.

 

5) The mounting of and material construction of the bridge influences the outcome. Moses Carbon Graphite USA has found instruments with mounted bridges that, although holding string tension, were mounted with gaps left between their base plate and the body beneath. Any such  space reaps similar results to that of a poor neck to heel pocket connection. Even a solidly set bridge is basically resting on the surface of the body, thus remaining discontinuous as an element as well as generally different in material composition and density.

 

6) The mating of the sub-components constituting the bridge itself have a tremendous impact on outcome. In essence, each individual part of a bridge is discontinuous and leaning against the other parts. Every time vibration moves from one sub-component to another across these discontinuities, energy is lost. We have found that the better the machining of the individual bridge elements, the better the outcome. But essentially, from the point-of-view of energy transfer, the fewer the individual bridge sub-components, the less the loss. One solution is to choose a bridge with the minimum number of separate parts that still satisfies the instrument and player’s requirements.

 

7) Strings that are anchored at back of the body (string through) not only change the string’s tension and focus, but often increase the mating of the string to the body. 

 

8) As a note decays, the material composition of the neck influences the set of frequencies which continue to sustain. Some woods neck, unevenly loose the higher frequencies as they play-out, so that during the later stages of decay, they are indistinct muddled and woofy. 

 

All of these complexities are exacerbated by the fact that a neck or other components with one ‘averaged’ set of desirable qualities may work well with another specific part, such as a body. And yet the same neck and body may not match-up with an alternate set of ‘good quality’ components. This is technically true. It is also perpetuated by the perception that a group of individual good parts necessarily dictates an excellent outcome. This is often the case. But although the old saying goes ‘the whole is greater than the sum of the parts’, it was never intended to mean that greater is better or worse. Greater is simply different in a larger way. So, as this pertains to necks and bodies, the qualities of an excellent quality neck may and generally does improve the outcome of an instrument. However, the averaged qualities of that neck may not match-up with the sum of the qualities of all other instrument components, especially the unique characteristics of each individual piece of wood. Overall, as a note decays the material composition of the neck influences the set of frequencies which continue to sustain. In some cases, the fundamental falls away, leaving uneven upper frequencies. A properly designed and well-crafted carbon graphite neck, mounted on a compatible body and complete with quality hardware and electronics, will provide sustainful musical notes with complete harmonic overtone series’ throughout their duration. So, the de-coupled mating of a wood neck or body with a carbon graphite neck or body usually does result in the elimination of deadspots. However, in some unusual instances deadspots may be only decreased, may move or in rare instances may increase. In these later and unusual cases, it does not mean that the other attributes of carbon graphite necks are not worthwhile. 

Carbon graphite necks always offer great stability with focused clarity throughout an instrument’s full range of function, and do eliminate deadspots in the vast majority of cases. 

 

  • facebook
  • New Moses Carbon Graphite USA neck models: the CS-27, a 24 fret custom guitar neck & MJ-144 A, a slanted fret neck for Fender 4-st basses.
  • Inlays and Finishes

    MOP Namaste/OM inlay MOP Block inlay on MJ-144 Jazz MOP & Paua 3d Star inlay 3-alternate-3+3-scoop-guitar
  • Moses Carbon Graphite USA offers Hipshot, Schaller, Gotoh, ABM and Sperzel hardware. We also offer Bartolini, Lace, EMG and other electronics.


  • Fiber Optic Position Markers

    See examples of awesome fiber optic fret markers in the Inlays & Finishes section!