About tone

Improving tone

About piano tone

Piano Quality

The tone of a piano is affected by a number of different factors. Firstly, there is the piano itself - different makes, and different models or sizes of piano have different tones. 

Even two pianos the same make and model will not necessarily have the same tonal characteristics, although we would expect them to be broadly similar. 

Generally speaking (although there are exceptions in some specific instances), larger instruments will be superior in tone to smaller ones. The greatest difference in string length occurs in the mid and bass range of the compass, and longer strings give a richer and more 'harmonic' tone. 

Larger instruments will be louder, not only as a result of longer strings, but also because of the greater soundboard area.

Pianos vary just as greatly in cost, quality and tonal characteristics as (for example) cars vary in cost and quality.

If you own a respectable, good quality piano, it is still not fair to compare it to a piano heard, say, on a recording of a piano concerto with the Berlin Philharmonic, which will invariably be of a concert instrument costing many times more (perhaps a hundred times more) than a 'domestic' piano.

The pianist

A piano, like any instrument, can sound like a different instrument in the hands of different musicians. The better the musician, the better the tone. This is because 'tone' is more than something determined by fixed acoustical properties of the instrument itself.

The tuning

Fine tuning affects the tonal characteristics of an instrument. An expert artist tuner will bring out the best from the instrument's inherent tonal potential, both in individual notes and as a whole.  

The toning

Pianos are toned as well as tuned, as a separate process from tuning. Toning consists of hardening or (more usually) softening the hammer felts. The shape of the hammer felts need to be regulated by facing or refacing with a special abrasive tool, whether the felts are new, or old, worn and grooved. The hardness of the felts is regulated by inserting toning needles into the felt, to soften it. Like tuning, toning is a highly skilled operation that should only be carried out by a qualified technician. Hammer felts can be irreversibly damaged by incorrect toning procedures. 

The condition of the piano

Wear and age is generally detrimental to tone. There are a number of specific reasons for this. The condition of the strings may deteriorate, and the condition of the bridges on the soundboard may also deteriorate, leading to a loss of tone quality and the introduction of tonal characteristics usually associated with poorer instruments, or poorly tuned instruments.

Wear to the hammer felts produces a flattened hammer nose, which dulls the tone or causes loss of clarity, and creates grooves where the strings are struck. If the hammers become even slightly loose, then sideways movement in grooved hammers can cause great unevenness of tone.

Wear and/or lack of regulation in the action can cause the action to lack sensitivity and response to the touch of the player, preventing proper tone production. The action itself may become noisy.

The damper felts may become hard, and may fail to be properly effective, causing notes to ring on after they are released, or causing undesirable noises from the strings

Cracks in the soundboard, contrary to popular supposition, do not necessarily cause tone deterioration. The soundboard functions as a composite structure, and cracks only appear along the soundboard grain, which would only interrupt sound wave flow across the grain. However, there are 'belly bars' fixed across the grain on the underside of the soundboard, specifically to create the elastic properties in the composite structure necessary for sound wave propagation in this direction. As long as these are intact and fixed, the soundboard can still function properly as a whole. However, repair may be imperative if the two sides of a crack are in contact, causing buzzing.

The acoustical environment 

The acoustics of the environment very much influence the perception of tone. A piano in a reverberant acoustic may have its positive tonal characteristics enhanced if the reverberation time is not too long. A large instrument in a small room may have any tonal imperfections very much exposed.

Improving Tone

On many pianos the tone can be improved. If the piano is an older instrument and the tone is too soft, this may be due to hammer wear. In many cases this can be corrected before taking the step of re-felting the hammers. If the tone is too harsh, bright or loud, this can generally be improved. Toning procedures are different from tuning, but the piano will need to be tuned also. A further follow up toning session may also be necessary, after the hammer felts 'settle down', following toning.