I’m delighted to have Stuart Mewburn from London, UK.
Q1. Could you please tell us a little about your luthiery and its history?
Born in Niagara Falls. Jobs: factory worker, miner, journalist, copywriter, creative director.
Emigrated to London in 1966. Built first guitar in 1972 from a book. Studied guitar making at the Guildhall University. Awarded mark of distinction.
Have had full order book since 1995. Make classical, flamenco and steel string guitars.
Q2. Please describe your idea of a good sounding guitar, and what you do to achieve it?
A good guitar should be capable of producing beautiful music in the hands of a competent guitarist. This means the guitar should be easy to play, and have even balance across the strings from the lowest note to the highest.
But what is a good guitar? There is no agreed vocabulary to define this. The sounds we hear – words such as sweet, harsh, loud, clear, bright, fuzzy, separation, projection, responsive can mean different things to different players.
In assessing sound quality it may help to know how a guitar works. When the strings are stroked, they activate vibration in the soundboard which pushes out airwaves. The vibrations are the sounds we hear. The two important parts of this sound are volume and quality. The first can measured; the second can't. Only our ears can tell us if we like the quality of the sound.
A problem for the player is that he or she sits in exactly the wrong place, behind the guitar, to hear what the guitar really sounds like.
So what control does the maker have over the sound coming out of a guitar?
As a guitar maker I have spent a good deal of time listening to guitars and wood. When selecting a soundboards I hold it at the nodal point one fifth of the way down the board and tap it in several places with the a knuckle of the other hand. If it rings it's worth buying.
I soon discovered that the best soundboards didn't have the finest grain. Wider grain produces a more open, ringing sound. The reason for this is that it is lighter than tight grained wood. The space between the hard annual rings is where moisture is sucked up the trunk of the tree and therefore full of tiny holes. When the wood is dried these become air pockets. It means that the strings will have less work to do making the board move up and down.
Western red cedar is lighter than European spruce and can produce beautiful top notes but has the disadvantage of becoming muddy in the basses when played hard and fast.
European spruce is excellent for separation between notes wherever they are played on the guitar.
When the wood is planed and sanded to it's final thickness (anywhere between 3 mm to less than 1mm) it loses it's ringing quality. The guitar maker must do something to re-establish the soundboard's ability to sing.
Only the lower bout of the guitar is used to produce sound. Using fan or lattice bracing here are the most common ways of stiffening the lower bout.
Fan bracing is 5 or 7 spruce (or cedar) spars spread out like an open hand.
Lattice bracing is criss-crossed pieces of balsa wood covered with carbon fibre on to a soundboard about 1 mm thick.
I use the fan method, sometimes bending the struts to give them more strength. After glueing them in place I tap the top and then remove material from the struts until I can hear the sound I'm listening for. It's impossible to describe what that sound is but I know it when I hear it.
When you think about it, the only purposes of the back and sides are to give rigidity to the structure and keep the soundboard away from the body. Rigid back and sides mean that less energy is lost when a string is plucked.
I use solid linings 8mm x 13mm thick to join the top to the sides and 12 6mm x 6mm struts to reinforce the sides.
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?
The standard string length of a modern classical is nominally 650 mm but is really 654 mm because of compensation. I have made a few guitars with shorter string lengths for people with smaller hands. But if you do have smaller hands and find chord or melody stretches difficult my advice is to use a standard length guitar with a capo.
The reasons are simple. A shorter string length of say 640, 628 or 615 mm lowers the tension of the string to achieve A 440 and therefore lowers the volume of the guitar. To compensate for this you need higher tension strings which begins to defeat the purpose of playability. A capo at the first fret reduces the string length to 618.5 but retains the same string tension. Of course the pitch of all the strings is raised by a half tone.
It is also easier to sell a standard length guitar when you feel it's time to move on to another guitar.
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?
It shouldn't be but trying a guitar in a shop can be very trying. If possible take another guitar player with you for support. They can play the guitar while you listen to what it sounds like and they can give you their opinion of it's sound and playability. Play only a few guitars and play them for a good time so you begin to get the feel of it. Don't be put off by the people in the shop or the owner. If you can't remember a whole piece take the music with you.
Very importantly make sure the guitar tunes properly. Take a digital tuner so you can check any frets where you feel the tuning is out. Play the top E string (open) then play the same note on the 2nd, 3rd, 4th, and 5th strings. If they are not all in tune with the top E it probably means the saddle isn't in the right place and guitar won't tune.
I've had professional musicians come to me who've spent lots of money in a shop but the guitar won't tune and they ask me to fix it. I can, but I put a ruler on the fret board, show them the saddle is not compensated enough and tell them to take it back to the shop.
Q8. How does the increasing rarity of some woods, rosewood for example, impact on your methods, and the quality of the end product?
The only wood that really matters in a guitar is the soundboard. The neck is usually cedrella, or Honduras mahoghany. All you want from the back and sides is rigidity.
Back and sides can be Walnut, Indian Rosewood, Maple, Yew, Cocabola,fruitwood (cherry, pair, plum) if you can find it big enough. I have enough stock of woods (including Brazilian rosewood landed in 1965 with a Cites certificate) to see out my guitar making career.
Q9. How do you see the future of this beautiful tradition in the 21st century?
I think the classical guitar will go on evolving as new makers experiment with ways of making, perhaps introducing new materials and perhaps shapes. Players will demand more in the way of amplification. For instance I am making a guitar at present with 5 pickups. Perhaps someone will think of a way to make a guitar that can reproduce the sustain that a violin bow can give to a violin or the range of notes of a piano. Who knows?