KAWAI
Technology
An in-depth look at the intricate mechanism that transforms a pianist's touch into musical sound — and why Kawai's Millennium III Action represents its fifth evolution.
In the beginning was the conventional wooden piano action. It evolved through three generations — and it was good. The 1980s brought the fourth generation of the piano action, the Kawai Ultra-Responsive ABS Action — and it was much better. Now, you can experience the fifth evolution of piano touch — the revolutionary Millennium III Action with carbon composite parts.
A piano action is an amazing mechanism with an enormous responsibility. Its crucial task is to transfer musical energy seamlessly from the pianist's fingers to the piano strings. To accomplish it properly, all 8,000+ parts of the piano action must remain stable and work together perfectly at all times. Even the smallest dimensional or positional change in any component part can hurt piano performance.
When a piano key is pressed, a corresponding hammer rises to strike the string (or strings) causing the highly-tensioned strings to vibrate. The energy of the vibrating string is transferred to the soundboard through a component called the “bridge.” Because the soundboard is mounted with tremendous tension (similar to the tensioned head of a drum), it resonates intensely when sound energy is received. It is the resonating vibrations of the soundboard that a listener hears as “tone.”
When a grand piano key is depressed, the other end of the key lifts upward with equal force. This key movement lifts a screw known as the “capstan.” The capstan is located under a multi-faceted hinged assembly called the “wippen” that contains an L-shaped part called the “jack.” The upward force of the capstan causes the wippen to rise, thrusting the jack upward into another component called the “knuckle” fixed to one end of the hammer shank. As the knuckle and hammer shank are forced upward, the felt hammer is propelled toward the string.
The hammer must bounce off (or “release”) from the string immediately so the strings can vibrate — even if the player holds the key down. As the jack raises the knuckle, it engages a component called the “let-off button” that causes the jack to release from the knuckle at the precise moment before the hammer hits the string. This “let-off” allows the hammer to fall away so the strings can vibrate freely after the strike.
What if the player wants to repeat the same note immediately? The end of the key is fitted with a component called the “backcheck” that rises as the key is pressed and catches the hammer as it rebounds from the string. The raised backcheck holds the hammer just under the strings awaiting another strike. If the note is repeated, the key only needs to be raised slightly for the jack to reset. This inventive design makes rapid repeated notes possible.
When a key is not being played, a component called the “damper” rests on top of the corresponding strings. When a key is initially pressed, the key pushes up on a component called the “damper lever” which lifts the “damper felts” off the strings. The pianist can also use the “damper pedal” (sustain pedal) to lift all dampers at one time.
A piano action requires thousands of individual components to work together perfectly — every time, over time. That's why Kawai introduced composite action parts over 50 years ago. Even the slightest change in the size of a part or its precise position will affect both piano tone and touch. For example, if the shrinking or swelling of any component causes the position of a hammer to be misaligned by as little as one millimeter, the tone and touch of a note will be compromised.
Since 1970, Kawai has invested millions of dollars to create piano actions with composite materials, including leading-edge carbon fiber. Because composite action parts are virtually impervious to shrinking, swelling or warping due to humidity, they remain extremely stable over time.
Adding carbon fiber to our renowned ABS-Styran parts increased strength by 90%.
With lighter ABS-Carbon parts, the Millennium III Action is approximately 25% faster than a conventional wooden action.
ABS-Carbon is more rigid and sends more energy to the hammer with every keystroke.
The jack is redesigned with a microscopic surface texture to provide unparalleled control for pianissimo playing.
The “action” is the mechanism inside a piano that transforms the player's touch on a key into a hammer strike. In the early 18th century, Italian inventor Bartolomeo Christofori created the first piano action. In the 19th century, French piano maker Sebastian Erard developed the “double escapement” design. Then, at the halfway point of the 20th Century, evolution stopped — except at Kawai.
As early as the 1960s, Kawai craftsmen recognized the serious problems associated with wood for mechanical action parts. Kawai invested millions of dollars to develop composite action parts, first introduced in 1970. By the 1990s, these efforts resulted in the Kawai Ultra-Responsive Action — the fourth major evolution. Kawai continued with the introduction of carbon composites — the Millennium III Action launched the “5th Evolution.”
Today, nearly fifty years after its historic introduction of composite parts, Kawai continues to be the leader of innovation — now the recipient of over 50 major international awards.
The best way to understand the difference is to play it. Find an authorized Kawai dealer and feel five generations of innovation beneath your fingers.
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