Detailed piano regulation is the bedrock of high performance tone quality. This action setup is the primary test signalling quality work in a rebuilt piano. Touch, repetition, evenness, responsiveness, feel, heaviness, lightness, quickness…are the essence of piano regulating.
Every piano regardless of make or grade deserves to be at its full potential – only then can the player be at their full potential. A skilled piano technician and piano rebuilder can make a huge difference in situations involving action geometry, poor performance, and complaints with touch.
Piano regulation involves the inner mechanism of the piano, separate from piano tuning. Within this mechanism the 9,000-12,000 parts need to be adjusted periodically in order to keep them operating as the manufacturer intended.
Players will often put up with very poor performance because they don’t recognize that there’s a problem. Many pianos are sluggish or slow to repeat. The pianist’s hands may be sore due to stiffness in the mechanism. Children may play for years on a piano that has excessive weight in the parts themselves. Some pianos have faulty design or setup from the moment they leave the factory. Common friction issues may go undetected for years until revealed during a weight-and-friction measurement and calculation. Geometry may change as parts wear out over the years.
A properly regulated mechanism is about maximum power! My own piano rebuilding work leads with this bias. Maximum power means optimum repetition and touch response, along with friction points and pivots that are not too tight or too loose, measured to within exact tolerances. Maximum power results in the warm, strong sound that most piano players prefer when doing comparisons. Maximum power provides the rich dynamic range of sound from tiny to huge.