Voicing the hammer head

Voicing ensures the tone quality by treating the hammer heads. Only experienced piano builders understand the fine art of working on an upright or a grand piano’s hammer heads at the highest level.

“Voicing” means giving tone. It is the art of influencing the sound character of your instrument by reworking the hammer head felts. Within certain limits, voicing can adjust the dynamic range, timbre and other parameters of the overall sound to your personal taste or indoor conditions. Through regular playing and constant impact on the hard metal strings, hammer head felt coverings condense and make the sound harder. When the hammer head felt fibres stretch due to exposure to high humidity, the tone becomes softer and duller. Such changes are not consistent and produce an unbalanced sound. With specialized tools and a lot of experience, a qualified technician can restore the initial state of the hammer head felts again.

Voicing is required if through heavy use your instrument shows variations in wearing and hardening of hammer head felts. Please note that depending on your needs the choice of your technician should be considered carefully. A hammer head consists of a wood core covered with felt. The quality of hammer heads can vary greatly depending on the manufacturer, which is why Bechstein has for its hammer heads its own high and clearly defined standards that must be met by the special operation supplier. The hammer head felt has tension. When voicing, i.e. inserting needles into the felt, this tension is changed. If the felt tension is very high or hardened, the hammer head produces a hard sound. To turn this state into a rich sound, the expert needs to proceed with a specific order of work steps. Voicing is an art mastered only by specialists. Submitted to an unqualified voicing process, hammer heads can permanently lose their necessary tension and must be replaced.

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