Aims.
The principal aim of my work is to produce good concert guitars which have the volume and response needed while retaining a rich tonal character, which is often lost when attempting to make guitars loud. I want to make an instrument where the player can express themselves easily and, something which has always been important to me, to express myself by making a guitar which sounds unique.
Although I use many tradition methods, over the years I have developed my own ideas to achieve these aims. The objective of these methods has been to make the instrument as lightweight as possible by reducing mass without compromising stiffness in order to make the guitar as efficient as possible. This has been the main concept for luthiers, particularly in the last few decades. The introduction of the sound-post to my guitars is a new idea and is one which I am developing along side my more traditionally made guitars. The sound-post has enabled me to make the soundboard much lighter, helping me to achieve my aims.
Methods.
Soundboard Design.
In the past I experimented with a number of ideas and ways of strutting the soundboard. These ideas have been based on making the structures lighter in weight while retaining stiffness. I have often incorporated carbon fiber into the strutting as a way of doing this. I began by using carbon fiber as an “I” section through the struts and also constructed laminated struts where a lightweight wood is sandwiched between two outer pieces of carbon fiber. I have inlaid these struts into the soundboard as a way of decreasing mass. Apart from a few forays into different strutting patterns I use the fan system now without carbon fiber. I rely on the sound-post as a means of decreasing mass in the soundboard. For the sound-post I used carbon fiber rod which is the best.
Laminated struts inlaid into soundboard
Sound-posts.
My latest development is the introduction of the sound-post, similar to that in a violin, a bar positioned between the soundboard and back. After many experiments I now position it directly underneath the center of the saddle and the back. To begin with I placed it between the center of the harmonic bar and the back. This post means that you can make the soundboard much lighter (below 2 mm), because it is supporting the lower bout so effectively. A lighter soundboard will therefore hopefully be more efficient.
Sound-post sound.
With such a post in the center of the guitar you would expect a certain amount of dampening especially in the lower modes of vibration. But due to the fact that it is a very lightweight structure in relation to the stiffness it creates, and the benefit of reducing the mass of the soundboard sufficiently, I think compensates for this dampening. The sound of the guitar is still full and I really like the quality of the sound. I can only describe it as a “blooming” sort of sound. It may not have quite the dynamics but it does have a unique musical quality. You have to drive the guitar a bit. The basses are more compressed but have good definition with a nice sustaining quality and a certain amount of fundamental in the notes.The trebles are strong and not thin or bright. The notes are even in response wherever you play and the quality of the notes are focussed and clear. From experience the projection is much better than on my non sound-post guitars.
On the question of how joining the soundboard to the back with a post affects the sound, most guitar makers would have negative opinions I think. The guitar works differently to the violin. The sound-post certainly makes the guitar sound different. This is what I find interesting.
Overall I believe this method of supporting the soundboard really works well and I’m looking forward to making more guitars this way. They sound modern but still expressive and have a unique tonal quality which I find exciting and which is very important to me. Another thing I particular like is its simplicity. It’s very easy to construct. I have thought about making double-top soundboards but they are complicated to make which I don’t like. In the beginning I was thinking what would happen if I tried putting a post underneath the saddle. I had a guitar whose frequency was about E which I didn’t like. I had be trying to make everything lighter but was loosing definition and clarity in the sound. It took me about 5 minutes to insert a sound-post and immediately the guitar sounded better. The frequency of the guitar went up to G sharp-A. I had a new thing going.
First sound-posts beneath harmonic bar.
The Back.
The back is laminated and made in a mould. The central lightweight core, usually cedar, spruce or cypress, is sandwiched between the outer rosewood etc, with an inner facing of carbon fiber weave. The mould gives the back its shape once the glue has hardened and the result is a stiff structure. I initially made the back this way to eliminate the need for strutting, and to produce a more uniform stiffness to it. Laminating makes the back nice and stable and less prone to splitting which I like and provides a good reflective surface for the sound to be projected from the instrument. And again it is a very simple structure, and is very easy to glue on. I have tried using a traditionally strutted back with the sound-post sitting on a back bar, but I don’t think it is as stable as a laminated back. The sound-post on a laminated back sits in a disc of ebony (about 3 cm in diameter), which is glued onto it.
The Look.
I try to keep both the construction as well as the embellishment of the guitars as simple as possible. purfling, binding and rosette are not overstated, and I try to just emphasise the pleasing shape the guitar can be. I use only french polish to finish the instrument for the natural beauty it gives the wood and the nice way it ages with time.
