to questions sent in by the readers:
I've heard that good wood for instrument-making is becoming
increasingly hard to get. What is your opinion about this?
What is being done?
Really beautiful, quality tonewood is indeed becoming scarce.
Some instrument-making companies have been stockpiling for
decades, and this makes it harder for the small hand-maker
like myself to find and purchase suitable wood. These instrument-making
companies, mainly in Asia, often use wood of a quality far
surpassing the quality of their finished instruments. Inadequate
drying, inappropriate adhesives and poor finishing dooms many
of these instruments to a short, trouble-prone life. Instrument
makers also compete with veneer mills for the most beautiful
wood. Enterprising bass makers are reacting by seeking out
and using alternative woods to the typical flamed maple and
spruce; walnut, poplar, willow, cherry, pine, redwood, and
cedar are all being used with good results. Ebony remains
the wood of choice for fingerboards and other pieces of trim,
but the quality is slipping because of hoarding and lack of
current supply. There is a rumor circulating that it will
soon be embargoed, just as Brazilian Rosewood has been since
the 1970s. Makers are looking into alternative woods to ebony
for fingerboards, and some are proving suitable. Man-made
composites are also meeting with some success. One thing I
find odd is that no one seems to be doing anything substantial
to ensure the future supply of fine tonewoods. I would hope
that at some point tonewood "plantations" might
be developed to supply future luthiers.
I had a cedar soundpost installed in my bass, and I like the
result. Do you think there is a reason it sounds better?
The soundpost is a region of the bass that is fraught with
mystery and misinformation. In order of importance, are; Position,
Fit, Tension and Material (mass). In my opinion a soundpost
is little more than a stiffener or piston. It creates an area
of the top table where little vibration occurs (an anti-node),
and it also spreads the string energy to the back of the bass.
When positioned in the "right" place, with the "right"
tension and fit, a bass will respond and sound great. When
a spruce soundpost is changed out for a cedar post of slightly
lower mass, most of the change in sound is probably due to
a slight change in position, fit or tension. I do believe
that the change in mass may have a small effect on a bass'
sound and response. However, my many experiments using soundposts
of different densities to change a bass' tone have been disappointing
How much camber, or scoop, should I have in my fingerboard?
That depends on how you play, and on what type of strings
you play. Generally, I like to see about 1.5mm on the G side
and about 2mm on the E side with the bass under string tension.
( A five-stringed bass with a low B string needs about 2.5mm
or so under the B string.) A bassist who plays aggressive
pizzicato will likely need more. A player with hand problems
or arthritis who plays lightly can get away with less. I've
read that classical players need more camber than pizzicato
players, but I have not found that to be true. Gut strings
require a bit more fingerboard scoop, as well as a slightly
higher nut. Luthiers disagree on where the lowest point of
a fingerboard should be; somewhere between the fifth and the
octave seems to work best.
Does my bass need a winter and summer soundpost?
Do you live in a very changeable climate? Do you have a flat-backed
bass? Does your bass tend to swell and shrink a lot with seasonal
changes? Sorry to answer a question with more questions, but
if you answered "yes" to any of them, you probably
do need both a winter and summer soundpost. Basses are quite
wide, and as wood contracts and expands mainly across its
width, changes in environment can cause a lot of tension in
a bass. In the winter, or dry time of year (especially with
indoor heating) a bass' soundpost can become dangerously tight.
This tightness can result in top table bulging or cracking.
In the summer, or more humid time of year, the post may become
quite loose. An overly loose post can cause some sagging of
the top table, and in some circumstances the soundpost can
fall over. Either situation is not optimal for playability
and sound. Flat-backed basses are more prone to the affects
of climate, as the braces in the back contract and expand
in the opposite way as the back wood, flexing the back and
creating more change in the distance between top and back
plates; hence the need for multiple soundposts. I like to
fit the soundpost for a round-backed bass in the spring or
fall, and in many cases it will work out okay year-round,
especially if the owner is careful about keeping the relative
humidity from becoming dangerously low during the winter.
What is purfling, and what is it's purpose?
Purfling is the thin inlayed stripe around the perimeter of
a string instrument's top and back plates. It is found in
most, but not all basses. Purfling is usually made of three
thin strips of wood veneer or fiber, generally in a black-white-black
configuration. It is installed in a groove which the maker
cuts into the plates, and is usually installed about 7-10mm
from the outside edge. Some luthiers make their own purfling,
while others use commercially available material. The purpose
of purfling is two-fold: 1) It looks nice, and shows off the
luthier's skill, and; 2) It can help to prevent damage to
the plates by resisting cracks spreading from the edges inward.
that's all for now. I'll be answering more of your questions
in future issues, so if you have one, please send it to ArnoldS@aesbass.com.
Happy thumping and sawing!
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