Technical data
| Line | Spirocore |
| Instrument | Violin |
| Size | 1/2 |
| Gauge | medium |
| Supplied as | Set |
| Item number | ST-S514-SET12 |
Scope of delivery
- Available as a complete set
Sound and physics
The construction of the string (string length, tension, cross section, material properties) keeps its overtones close to the harmonic series; the higher partials lie only fractionally above the exact multiples of the fundamental. In wound strings this is achieved by the composite design of a thin, flexible core with one or more windings of metal ribbon or wire, which puts a lot of mass on the string with little bending stiffness.
A string tuned to the same pitch on the same string length carries proportionally more mass per metre (linear mass density) when it is under higher tension.
Under the bow the travelling kink of the Helmholtz motion (the string sticks to the bow hair and slips back) stays sharp on the flexible string, and the bridge receives a sawtooth force that contains every overtone of the fundamental.
The violin is tuned in fifths; at A = 440 Hz and pure fifths the open strings G, D, A and E sound at about 195.6 Hz, 293.3 Hz, 440 Hz and 660 Hz.
The E string is usually steel today, because gut would be loaded to the limit of its breaking strength in this position. Steel stretches far less than gut when tuned, which is why a steel E is tuned most finely with a fine tuner in the tailpiece. The low G string sounds rounder and fuller than the higher strings; composers therefore ask for whole passages on it (sul G).
With the Thomastik synthetic sets we carry, the longitudinal pull lies between 21.2 kg (Dominant 135) and 23.5 kg (Rondo); angled over the bridge (string angle about 157°), about 8.5 to 9.5 kg of it press the bridge onto the top. Towards the G string the strings sit higher above the fingerboard, because their amplitude grows towards the low strings; the bridge is cut asymmetrically to match.
Spirocore violin strings are built on a spiral rope core of steel with chrome winding; in the 4/4 set S15 the E string S9 is aluminium wound. The steel of the core (7,800 to 8,000 kg/m³, modulus of elasticity as a measure of material stiffness 190,000 to 210,000 MPa, roughly 55 to 85 times that of a synthetic core) is more flexible as a multi wire rope than a single wire.
Steel hardly stretches when tuned, so Spirocore is tuned most finely with fine tuners. The strings hold their tuning for a long time and are unaffected by temperature and humidity. Their chrome winding of chrome nickel steel protects itself from corrosion with a self healing chromium oxide layer.
When another model suits you better
If you prefer a synthetic core, Dominant is a set that shows a violin neutrally and honestly and is made down to 1/16.
Frequently asked questions
Why are the lower strings wound?
The winding adds mass to the string without making it stiff. On the same string length a low note at similar tension needs a much higher linear mass density, and the metal of the winding supplies it.
How much does tension change when I tune higher?
From 440 Hz to 442 Hz, as many orchestras tune today, tension rises by about 0.9 per cent, and to 445 Hz by about 2.3 per cent.
Does a fine tuner for loop ends also take ball end strings?
No, our fine tuners are made for loop end strings. For a ball end string you choose a tailpiece or fine tuner that takes a ball, or a string with a removable ball.
How long does a Spirocore set take to settle in?
For the Spirocore spiral rope core the maker gives about one day.
Do I need fine tuners for steel strings?
We recommend them, because steel hardly stretches when tuned, and the fine tuner hits the small steps more easily than the peg.
