tension. The higher tension imposed on the Paulello string is possible because its mass and length are greater, and Paulello’s tensile strength is significantly greater than the Roslau, illustrated by the breaking point figures.The yield or capacity of the Paulello/Stuart. wire is 46% higher than Steinway/Roslau. The composite of materials used, and the proportion of the amount of tension to the breaking point of the string are a matter of tone and the taste/choice of the piano maker.
The Stuart strings are significantly longer, a factor which is known to reduce in harmonicity of wound strings136. A reduction of in harmonicity means reduced prominence of the in harmonic frequencies of the string, resulting in a more pure sonorous sound. A wire with a higher capacity of yield produces a more satisfactory sound.137
| C265.406 Hz Stuart | M19,STU | C265.406 Hz Steinway | STE |
| PAULELLO / M nickel-plated surface. |
ROSLAU high-tensile Swedish steel |
||
| M bichord (2 strings) | Trichord (3 strings) | ||
| Length: | 1836 mm | Length: | 1601mm |
| Cor dia: | 1.075mm | Cor dia: | .950 mm |
| Cover dia: Stainless Steel wrap |
2.175mm | Cover dia: Copper Wrap |
1.702mm |
| Wrapping weight | 7g per cubic cm | Wrapping weight | 8.9 g per cubic cm |
| Tension | 134.099kg 1387.9 N |
Tension | 68.7272kg 673.9N |
| Nominal breaking load | 2097N/mm² | Nominal breaking load | 1616 N/mm² |
| Yield | 88.25% | Yield | 42.8% |
| C2 String Scale Table 1.5 | |||
C3String Scaling
The scaling of the strings for C3 130.81Hz, of the Steinway and Stuart, present a different scenario to C2. The strings for C3, are set in trichords of steel music wire, Stuart using Paulello ‘M’ wire, and Steinway using Roslau wire, both of similar thickness 1.125mm. The Steinway strings are longer by 41.5mm, and the composite materials of the steel wires are different, with differing drawing methods producing contrasting yield and breaking points. The tensile strength and stress % of the yield point is greater in the Paulello string by 140 Newtons per square millimetre (N/mm2). The different rates of tension illustrated in table 1.5 above are part of the equation due to differing string lengths and string material stiffness. The contrasting ‘hardness-stiffness’ of the music wire is illustrated by the contrasting breaking point, the higher the breaking point potential, and the harder or stiffer the wire.
…..the string , considered in its length, diameter, tension and point of agitation, is the most important factor in the production of tone.138
136Neville Fletcher, and Rossing,T.The Physics of Musical Instruments(Springer, 1998) ,388.
137 2 Fletcher& Rossing ,362.
138 3Wolfenden, Art of Pianofarte Construction,15.
