The Wikipedia definition of a Luthier is someone who repairs or builds string instruments. Wikipedia should also say that Luthiers spend most of their time cutting big bits of wood into smaller bits of wood and then sticking them back together again.
The following two recent discoveries or revelations are examples of refinements in this process. They have deepened my understanding and also improved the performance of my instruments. Both revelations occurred when working on unrelated issues.
To explain the first one I need to give a little background:
As most musicians would know when a string is plucked it vibrates or oscillates in a number of ways. There is the primary or fundamental vibration and a range of octave and harmonic movements. The soundboard will, to a greater or lesser degree, transmit these movements. A good example of the variation is where the E or bass string on some guitars is a deeper note than on others. This is because the instrument is doing a better job of transferring the fundamental movement of the string.
Conversely if an instrument successfully transfers the high frequency octaves and harmonics on the thin or unwound steel strings the sound can be a little harsh. This has been the unresolved problem I have had with my radiant soundboard design. Using thinner strings reduced the problem but loss of attack or punch was also reduced. I had concluded this was the “price payed” for designing a sensitive sound board.
As it turned out the excessive high frequency problem was resolved when experimenting on a completely different issue. The temporary sound board being used had no finish applied to it. It was a total joy to hear the resultant clarity of sound without the high frequency imbalance. I have since concluded that the best finish is no finish. This of course does not apply to the violin where the very high notes are almost totally reliant on the finish.
The industry standard finish is still nitrocellulose and I am pleased to say that I no longer use it. I now use an Australian designed post cure shellac. It is very sparingly applied to the soundboards and its interference with the sound is minimal.
A little background is also needed for the second discovery:
As an exhibitor in a recent guitar makers festival my initial plans were to bring 8 instruments. This turned out to be an outrageously optimistic intention. As the festival weekend got closer the number of instruments was revised down to 5 then 3 and finally a week before the festival I chose to finish just one. . . .a 12 string guitar which had been ordered by a local guitar collector and I must say I am very proud to have an instrument in his collection.
To finish and fine tune this instrument on time I had to work 36 hours continuously and then 3 hours later get on a plane and fly to Melbourne where the exhibition began one hour later. Fortunately the unique nature of the guitar did much of the talking for me and I was pleased to get through the first day without falling asleep. Although I had nearly failed to bring anything to this festival the pressure that I had place myself under in the preceding weeks had forced me to revise many of my processes in an attempt to be more efficient. It is one of these processes that I would like to explain.
One of the design features in the necks of my instruments has been taken from the inspiration of Ken Parker. I believe this man is on the “cutting edge” of instrument design. I use the Ken Parker style of neck attachment and like many makers carbon fibre is incorporated into the composite necks that I build. This makes it possible to eliminate the use of a heavy adjustable truss rod. My carbon fibre reinforced necks have to be built with perfect relief or curvature on the finished fret boards. Once this relief has been achieved changes by the player in tuning or string gauge will not effect it. The technique I used to get this relief was sanding of the fret board before and after it is attached to the neck. In an attempt to eliminate this dirty tiring and time consuming process I firmly fixed the neck in a vice and then began tapping a wedge under the headstock until the neck had perfect curvature. The fret board was then glued on.
For reasons that I can only speculate on this new approach has resulted in a neck that is extremely stable. Instruments that have since been constructed this way no longer need a break in period where fine tuning adjustments need to be made. I have always believed that a very light and also a very stiff instrument neck is optimal.