"Hand-Built" Not Going Out of Style Anytime Soon
by Don Mannino, MPA, RPT
As a company that arguably makes the widest range of pianos in the industry today, from low-cost console pianos for the home (with many thousands built each year) to very expensive and limited-production concert grands for the stage (only about 12 per year), we at Kawai are perhaps uniquely qualified to speak of the different processes used to make pianos, and the results they make in the final product.
The important factor to remember is that, along with processes and machines, all pianos are made by people. The very high skills of the most knowledgeable and experienced craftspeople, applied to the construction of an artist-level piano — that is, what might be called "handcraftsmanship" — definitely lift the instrument to a higher level than can be achieved using normal production methods. This is borne out by the testimony of both experienced piano tradespeople and, perhaps more important, by pianists themselves when comparing similar pianos made using different processes. Pianists sampling well-prepared examples of Kawai RX and Shigeru pianos will almost universally acclaim the superior tone and touch of the handcrafted pianos, even though the designs are very similar.
Shigeru Kawai has found a unique way to incorporate the benefits of both styles of production into our pianos. It is possible to use extremely precise CNC machine processes in some areas of the piano where they are beneficial to the instrument, such as plate casting and machining, accurate indexing systems for consistency when assembling major sections of the piano, and manufacturing the small parts of the action, which benefit from extreme precision in all of our pianos. But for the finest pianos, some processes will result in a better instrument by being carried out in a slower, more traditional method by the most highly skilled artisans. A blending of both traditional hand work and precision CNC production has proven extremely successful for Kawai. The balancing of these processes, plus the selection and handling of the raw materials, combine to create the musical instrument that our customers desire.
Let me illustrate by providing an example. Hammer felt is ordered from the felt maker with very precise specifications for fiber type, thickness, and density. Yet when it has been cut and pressed into a set of hammers using very accurate CNC machinery, two sets of hammers made from the same sheet of wool can sound different. When comparing hammers made from one sheet of wool with those made from another sheet, there is even more potential for tonal differences, even though the specifications are verified and measure exactly the same. One could argue that the specifications are not precise enough, but the "resolution" of our measurements simply cannot take into account how the wool fibers will stretch and pull against each other in the hammer press, changing the tone of the hammers. Pressing them with high heat and extremely consistent machinery helps make them more consistent and predictable, and most higher-volume piano makers use hammers made in this way — but this type of hammer does not have the potential for as wide a range of tone colors as hammers made with the slower, hand-pressed method.
In the end, the best way to control the tone is for experienced people to make the hammers, and for experienced people to adjust the density and shape of the felt by voicing the hammers at the end of the production process. For the Shigeru hammers, years of testing and experimentation in our Research and Development laboratory taught us that a hand-operated hammer press worked by an experienced craftsperson allows the pressure to be fine-tuned according to the feel of the wool in the press. In addition, pressing the hammers with very low heat affects the resilience of the felt and makes it possible to voice the hammers with a wider range of tone. The Shigeru Kawai hammers require at least six hours in the press, as opposed to 15 minutes for many production hammers. This "cold press" process would be too expensive, requiring many highly skilled workers and many more hours of labor, for high-volume-production pianos. But for limited-production, higher-priced instruments it is possible to spend this extra time, and the buyers of this level of piano will appreciate the range of sound and tonal control provided.