I’m delighted to have Graham Caldersmith — Caldersmith Guitars from Ausralia.
Q1. Could you please tell us a little about your luthiery and its history?
I began research into the physical behaviour of guitars and violins at the Aust. National University in 1974 after completing a masters in fluid physics. After intensive research with Prof. Neville Fletcher at UNE,Armidale and with Prof. Erik Jansson at KTH in Stockholm I began making experimental instruments in Canberra, ACT, in 1979 and reverted to traditional designs subsequently when I realised guitars and violins head evolved into those forms for good reasons!
During the 80's I made several dozen violins, violas and cellos and serviced the repair needs of Canberra musicians. I wrote many research articles on violin and guitar vibration and sound generation using equipment granted by the Aust Research Council in 1980, aged equipment I still use today!
I also began to develop a classical guitar family and made prototype bass and treble guitars with an Australia Council Grant which were used in the initial performances of the Canberra based Guitar Trek who continue to tour and record using upgraded instruments. The Guitar Family is now also used by the Melbourne Guitar Quartet in Victoria, Freternity in NSW and the ZooDuo and colleagues in Holland. There is a wealth of Guitar Family Music on youtube much linked on the Caldersmith Guitars website. Some professional musicians augment their performances by playing solo pieces on the baritone, as well as using it in ensembles.
In the 1990's I began to develop lattice guitar designs as part of a company of Australian makers departing traditional forms and incorporated lattices into Guitar Family instruments. In the 2000's with my partner Angela I developed the 'Grange' lattice design to supplement the balsa/carbon fibre graded rectangular lattice design and we now use both types of lattice in our standard and Guitar Family instruments: Bass, Baritone, standard, treble and octave, more details on the website.
Q2. Please describe your idea of a good sounding guitar, and what you do to achieve it?
A good sounding guitar should have projection, sustain, balance and tonal bloom.
Projection requires efficient sound production across the frequency range 80Hz to 5KHz. In our designs this is achieved by minimising wasteful vibration in the back and sides (making them very stiff) and confining the active light, lattice-braced soundboard to the rear bout so that wood losses are reduced and radiation is increased. The lattice is graded so that the area around the bridge is very stiff and the edges are flexible which increases efficiency of the multipole vibration modes between 550 and 2000 Hz.
Sustain is achieved by minimising the loss of vibration to the back and sides and the loss in the soundboard so the spectrum of partials in each note decays slowly allowing colourful vibrato on every note up to the 20th fret (C). This rarely happens on traditional guitars.
Balance is achieved by profiling the lattice so that the resonances of the soundboard and the dips between them occur at compensating frequencies: eg a weaker fundamental is compensated by strong second and third partials. The soundboard is clamped onto the body before gluing and the resonances adjusted to preferred frequencies by reducing the lattice bars or the carbon
Tone quality depends on the overall design of any guitar and in our lattice guitars the low losses to the back and sides and light soundboard generally result in sustained overtones, conferring tonal 'bloom' and enhanced vibrato. Inevitably, as in all guitars, some treble notes close to strong resonances lose their fundamentals more quickly, but we minimise this by stringing up new instruments before lacquering and making fine adjustments to resonance frequencies. The sustained fundamentals to notes above the 12th fret provide rich, strong partials to lower notes characteristic of our designs. Modern carbon fibre strings also have lower internal losses and accentuate the sustained character of lattice instruments.
Q3. Please tell us about your idea of improving playability, and what you do to achieve it?
Our necks are fitted with double acting truss rods which enable adjustment of neck relief through the soundhole without loosening strings. Unfortunately ebony has a high rate of expansion/contraction with humidity variation which usually changes neck relief and leaves fret ends projecting in dry weather as well as changes fingerboard cross curvature. Our fingerboards are crowned to allow some shrinkage and avoid concavity across them. Most players, but not all, like the crowned fingerboard. The bass side is 1mm lower than the treble so the saddle is almost level which seems more comfortable for the right hand, keeping the treble strings higher.
The truss rod allows us to make neck depth lower (say 15mm) without excessive upcurve due to string tension.
Necks are continuous to the top frets and bolted onto the body to avoid kinking at the 12th fret due to small movement of the front block. They are easily removable for adjustment or repair. This design also allows for movement between the ribs and heel and between the upper fingerboard and guitar top without cracking the finish.
Q4. Please tell us your opinion about the traditional finishing method (French polish) and new methods (lacquer, catalysed finishing, etc).
We admire the skill and beauty of French Polishing, but spay nitrocellulose lacquers after pore filling because they are waterproof (we rub back and polish with wet paper and polish) and resist sweat. They are easily repaired and polish to a gloss (back and sides and neck)or a sheen (top) with superfine steel wool.
If we rub through in final polishing we French polish over with hardened shellac which polishes to the same gloss as lacquer after setting.
Q5. Please tell us your opinion regarding shorter-scale guitars such as 640, 628 and 615mm in terms of playability, design, sound quality and volume. Is there an increasing need to cater to smaller-handed or female players?
Our standard scale is 650, but we are happy to make 640 and 630 scales and do not find any deficit in tone if fitted with modern medium/hard tension strings or hard tension strings.
Q6. Many readers say they end up being very confused after trying many guitars. Could you give us some advice on how to examine the guitars' sound quality and playability at a shop or luthier, from the guitar-maker's point of view?
Play notes on the top string from the 10th to the 19th or 20th frets and listen to the sustain and volume of these notes. Then play the notes one octave lower on two or more strings and listen to the tone quality ('bloom') of those notes.
Play notes on the top string from the 5th to the 10th frets and see if any 'dump' unpleasantly leaving only a thin overtone sound.
Find the note of the air resonance, usually F#, G or G# (even A on some guitars) by watching for fast decay of the bottom string amplitude from the side. You will also hear a strong, short fundamental to the sound. Guitars with balanced overtones will minimise this effect and you will not find it a problem when you play from low E up to C in a chromatic scale.
Find the note of the main top resonance, usually G, G# or A on the G-string by watching for fast decay and again hearing the strong, short fundamental which may be a starting 'boomp' rather than part of the note. Guitars with balanced overtones will minimise this effect and you will not find it a problem when you play through those notes on any string. If this main top resonance is an octave above the air resonance, as it often is, the bass is usually uneven.
Play several chords with both open and fretted strings to higher positions and listen to the decay of the treble notes relative to the bass notes. Trebles usually decay faster than basses, but longer treble sustain is an indicator of guitar's efficiency and expressiveness.
Play low and high scales hard and soft and listen to the quality and clarity of the notes in both cases. This indicates the guitar's dynamic range, a valuable musical asset.
Play between sultasto and ponticello on low and high notes: is the tone and volume easy to control? (the higher overtone content is responsible for this variation)
Q7. Do you offer any 'after-sales' service to customers - particularly customers who are nervous about making a substantial investment?
We fix any non-accidental fault in our guitars no charge even after 10 years, freight charges negotiable. In guitars sent overseas we pay for adjustments or repairs by luthiers. For serious faults like cracks we offer to replace the guitars, freight charges negotiable. For instruments ordered found unsuitable we repay deposits after the instrument is returned and sold. Where possible we service new instruments (fret dressing, truss rod and saddle adjustment) free, freight negotiable.
Q8. How does the increasing rarity of some woods, rosewood for example, impact on your methods, and the quality of the end product?
We import Indian rosewood, maple, and rainforest species from CITES registered suppliers. However we use several native Australian tonewoods from the mainland and Tasmania. Because our designs minimise the tonal influence of backs and sides, and the lattices determine most of the top vibration we do not depend on the acoustic quality of the woods as much as traditional instruments, but we pay attention to the aesthetic appeal of all woods, using richly coloured and figured woods in our composition.
Q9. How do you see the future of this beautiful tradition in the 21st century?
Naturally we hope our designs bring new dimensions to the performance of classical guitar music and composition, particularly the Classical Guitar Family which has generated unique arrangements by talented guitarists and recordings of orchestral, keyboard and string ensemble works, even Bach's Toccata in D minor for organ and Vivaldi's A minor double violin concerto (Melbourne Guitar Quartet). Composition for the Family continues to produce a canon of new works from a company of Australian composers and performance on the family offers avenues for fine players who cannot access solo careers.