FAQ

What is Voicing?

Voicing (sometimes known as tone regulating) is fundamentally the process of 'creating' or 'building' the sound / tone of a piano.

When piano hammers are fitted to the action they are generally 'raw' which means that they have received no treatment since their manufacture (except maybe some liquid lacquer to bind the fibres) and are generally quite hard physically and audibly. This is because the felt is applied around the hardwood core under high pressure or tension in order for the hammer to retain its shape and give long life and 'volume' to the sound.

To 'voice' the hammers, firstly they are filed by the technician to create a specific shape and then they are fitted to the strings correctly so that the 'nose' of the hammer strikes all three strings (in the tri-chord sections) at exactly the same time; this process is repeated in the bi-chord section. Then very carefully the hammers are voiced by inserting needles of different lengths and at specific points into the hammer felt. The hammer nose is repeatedly re-fitted to the strings during this process to retain an immediate and focused sound that is rounded but retains a full dynamic range rather than a muffled or nasal tone.

The technique of 'needling' the hammers takes many years of experience and is a highly skilled operation that should only be undertaken by an experienced technician in order to obtain a correct result whereby the different levels of playing (from pianissimo through to fortissimo and everything in between) give a pleasing sound without being too soft or resulting in a nasty, edgy sound when played loudly. Incorrect voicing by a novice can result in destroying the
hammers and dynamic range of the piano.

A piano will become harsher and louder in tone over time through playing, therefore it should be voiced periodically (depending on the amount of use it gets) in order to restore its musical tone.

What is action regulation?

All modern grand pianos have what is known as 'double-repetition' or (the other name) 'double escapement' actions. Put simply, this means that the note of a piano can be repeated quickly without having to release the key fully to its resting position. On playing a note, a slight release of the key re-sets or prepares the action for the next strike, this allows for very fast repetition of notes and fine nuances of playing that would otherwise be impossible. To achieve this correctly the action must be very finely set up to maximize 'response' and 'touch'; therefore action regulation is the process of making sure the piano plays correctly and 'feels right' under the fingers.

For those of you with a technical interest (or have nothing better to do), the basic process of action regulation goes like this:

First of all the keys are set at the correct height and are perfectly levelled; then adjustments are made to the action components to ensure that the different settings are finely set up, such as the 'blow distance' (the distance between the hammer at rest and the string). 'Set-off' (the point at which the hammer falls away from the strings just before touching them), 'Drop' (the distance that the hammer falls away from the strings immediately after set-off), these two settings prevent the hammers from 'blocking' onto the strings which would have the effect of none-sounding of the notes, as the hammers themselves would act as a damper. Depth of touch of the key is set in relationship with the 'blow distance' of the hammer and the amount of touch washers under each key (each has a affect on the other).

Then there is adjusting the tension of the repetition springs so that they are at the right regulation and an even response throughout the keyboard. This spring lifts the hammer slightly (after it has gone into check*) to allow the 'jack' to return to its place under the 'roller' when the finger is released slightly from the key, so preparing it for the next strike or repeat of the note.

On striking the key moderately, the tail of the hammer head is caught by the 'check* head' which holds the hammer in place to allow the repetition spring to do its work.

The action is then weighted i.e the weight of down-touch and up-touch are carefully set, which is also critical to the feel of the action. This is achieved by inserting or removing lead weights from the sides of the keys. Too much 'leading up' can cause action difficulties, one of them being inertia problems, usually resulting in the correct down-weight but not enough up-weight; therefore action response is compromised.

There are other regulation adjustments that I haven't mentioned here so as to not go into too much detail, but these are the fundamentals of action regulation on a modern grand piano.

There are measurements that are used to set all these parameters, but the best and most experienced technicians still rely on their skills and experience to do a lot of these adjustments by feel.