Importance of great materials
One of the most important things to evaluate in any guitar is the quality of materials. I am fortunate to be located near one of the most extensive collections of exotic hardwoods in the nation, at Keim Lumber in Charm, Ohio. I consider it both a great luxury and somewhat of an advantage being close to such a wonderful source of materials.
Remember, it's not all about looks. Although I pride myself in building beautiful guitars with proper form, balance, and unique wood appointments, it's the quality of each piece of wood that is most important. Stability, proper moisture content, grain direction, and lack of imperfections are all aspects of the wood that I pay close attention to. These characteristics contribute to a long-lasting instrument.
Tests will show that laminating two or more pieces of wood together increases both the long-term stability and the strength of the piece. This is why I typically use laminated necks. In addition to providing stability and strength, I also believe that a stronger neck leads to improvements in many aspects of the tone of the instrument, such as sustain, power, and clarity. The primary location I want the energy of the strings to be delivered to is the saddle. The more energy found there, the better. It is where the creation of tone begins. The acoustic guitar is so inefficient at actually turning the energy of the vibrating string into sound, that every effort must be taken to deliver the energy to the correct place.
The second aspect of neck construction worth mentioning is my proprietary carbon fiber reinforced headstock joint. Two quarter inch carbon fiber rods are installed at an angle perpendicular to the weakest point of the neck / headstock juncture. The reinforced headstock is very rigid, reducing the risk of the dreaded headstock fracture.
Following the same principle as laminated neck construction, I also apply laminating techniques to the construction of the sides. I use a three-laminate system, which creates an incredibly rigid but lightweight rim assembly. In order to create what I call a "torsion box" in any laminated piece, three or more laminates are needed. This creates opposite modes of tension within the piece, allowing it to hold its shape much better than the commonly found two-piece laminated side assembly. Because the shape is held so well, zero tension is introduced into the sound box through the pushing of the side assembly into the body construction mold, which is a commonly needed practice when using non-laminated sides. Tension in the side assembly creates unwanted resistance in the top and back vibrating plates. By eliminating any tension, the top and back are free to vibrate freely as the strings' energy directs. I would also point out that three laminates further improves the long-term stability and adverseness to cracks.
Role of the back plate
Much of my study of the acoustic guitar has been led by Ervin Somogyi, who describes the soundbox as being a sound pump in which the role of the back is to act in concert with the top, creating maximum efficiency. As such, my back plates are tested and tuned individually to become very active, and complementary to the soundboard.
There is much that could be discussed when writing about the bracing of the top, since it is one of the most important contributors to the instruments' overall sound. I have spent much time and effort on finding the "voice" of my guitars. Trial, error, and risky decisions on past guitars have led to where I am now with my own proprietary design. I believe that this design is perfect for the modern finger-style guitar, creating a very full, balanced sound with good volume, clarity, and sustain. I am also able to use other variations of the traditional x-brace design when tonal requirements demand it.
Tuning the instrument
To build an instrument that is interesting in any way, it must be "tuned" to deliver a musicality that is interesting and satisfying. I use two separate processes that work together to accomplish this goal. First, I use deflection testing on both the top and back plates before bracing is applied. I have specific deflection ratings that are used for the top and back on each body style. Because no two pieces of wood are the same, this is a very important step leading to better consistency. Second, by carving braces and manipulating the thickness of the plates as I build, I tune the top and back while monitoring the results with a spectrum analyzer, which gives detailed information about the resonant frequencies. My goal is to arrive at complimentary fundamental frequencies between the top and back, which create a very rich and satisfying sound. This is a very time consuming process which takes into account every part of the soundboard assembly, including the weight of the bridge pins, saddle, and even the finish.
When it comes to the protective finish of the instrument, I consider two factors: how durable, and how thick (or heavy). For this reason, I use the same polyester resin finish that is used by many other world class builders (and factories). The final finish thickness on my guitars is consistently between 4 and 5 thousandths of an inch, which I feel is the optimum thickness for both durability and tone. Polyester is very hard (the hardest finish available), and will stand the test of time. Builders, such as Kevin Ryan, have shown in their own personal tests that it holds up much better to cold weather and changes in humidity. Having said all of this, I will agree with many others that there is no perfect finish, and that it can be a subjective aspect of the guitar. I have used both french polish and nitrocellulose lacquer in the past, and each one has its own particular advantages and disadvantages.
Excellence in workmanship
I believe that patience and attention to detail are things that come from within. These qualities are a result of plenty of sleep, peace in life, and a joy for the building process. There are also the aspects of skill and know-how. Skill is both inherent to each individual and fostered through practice. I have been working with my hands in many creative ways for as long as I can remember. Fixing, building, creating, playing; these are all things that are a part of who I am. Know-how comes from being curious, then doing, and then doing it better. I love being a problem solver, and I love being inventive.
Any given process in guitar building requires great amounts of patience, attention to detail, skill, and know-how. It is my goal and my hope that my standards for excellence in workmanship will be self-evident when you pick up any Gerber guitar.