Soundpost adjustment for fine tuning B1 modes & wolf elimination
For some times I have been studying wolf note on B1+, soundpost adjustment and how it affects B1 modes. Previously on Wolf note
As usual the best way to confirm is by experimenting with real violins that are tuned within "normal" limits, typical graduations and B1-/+ modes between
440-460/530-550 Hz. After several tests on three violins with shorter and longer soundposts (without stress) I am sure about how it works.
The simple solution is to adjust the soundpost towards the middle for higher frequencies and towards the treble f-hole for lower frequencies. Keeping the adjustment within reasonable limits it is possible to adjust modes +/- 15 Hz. This is also confirmed when adjusting The Titian Strad's sound post in Strad 3D and Colin Gough's FEA research: VIBRATIONAL MODES OF THE VIOLIN FAMILY - Proceedings of the Stockholm Music Acoustics Conference 2013, SMAC 2013, Stockholm, Sweden, Colin Gough FEA
The adjustment does not go without compromise, the best solution is to have the modes right from the beginning so that the soundpost is in the middle under the right bridge foot.