The "Rubio six"or acoustical research using a grant from the Royal Society.
The violins were made by the luthier David Rubio, using carefully matched raw materials and embodying deliberate variations of constructional details which were controlled by vibration measurements during construction. Externally, the instruments are very similar so that it is possible to do experiments in which players are handed one instrument or another and asked to comment on their qualities, without being able to tell the difference by look or feel. These are now among the most measured violins in the world. They are also probably the only items of the Department's laboratory equipment whose value goes up rather than down as time passes!