| Question: If the sound board is the "speaker" why cut a
hole in it? Just tradition? Ease of access to the braces for repair? If it is so hard to
brace around the intrinsic weakness of the "sound hole" which I understand
should more accurately be called an "air port", why not put the hole somewhere
else, a la [Linda] Manzer guitars' side port? (Marc Durso--June 16, 1999) Answer:
The "speaker" metaphor is sometimes used in describing soundboard function,
Marc, but it isn't apt: the soundboard doesn't work that way. Instead the soundboard
conveys sound waves to the body cavity which are modified by the back as resonator. The
soundhole constricts and focuses the resulting sound waves as they emerge, and this is
crucial for the the actual tone outcome. If there were no soundhole, you'd get next to
nothing in the way of tone, because the soundboard surface alone would scatter the sound
waves. Alternative sound holes (e.g. Manzer's side port) are valid alternatives. Such
options have to be judged on the actual tone outcomes they produce. Actually it's not
particularly difficult to brace around a soundhole: I use a rather large soundhole pad
which seems to work quite well. |
|
| Question: I would appreciate some guidance on whether
to choose cedar or spruce as a top wood. Jeannouel van Leeuwen,
Cura�ao, Netherlands Antilles--July 1998.
Answer: A full account of the difference between these woods is
not easy to put into words, but let's give it a try. An important luthiery
consideration when using these woods is that cedar is generally lower and
density and has a little higher stiffness/weight ratio than spruce. Cedar
typically produces a sound which is warm and "Spanish." Spruce
is more likely to produce clarity and a larger tonal palette. Cedar
guitars are usually louder up close, although some spruce guitars (but not
all!) project better from a concert stage than might be expected in an
up-close comparison with a cedar-top. Opinion varies as to why this might
be so; it is my conviction that the primary physical variable is fullness
in the overtone structure of the treble notes, e.g. the upper partials.
(The human ear treats partials as additive, which can make a musical
instrument sound louder than a decibel reading recorded electronically
might suggest.) |
|
Question: I have always heard that Brazilian rosewood is the
best wood for a guitar's back & sides. It's a lot more expensive, but is it
really better? (Gus Bauman, Belton, MO--November 28, 1997)
Answer: The best answer to this question is that it's different
from say, Indian rosewood, the alternative most commonly used for classical guitar backs
& sides.
The real tonal difference between these woods is very slight and probably impossible to
describe in words. One of the few reasonably rigorous experiments I've done in my
guitar making career was a tonal comparison between two instruments made with Brazilian
and Indian rosewood. There was very little tonal difference between the two guitars,
and I found myself unable to link the difference heard by the test listeners decisively to
the back/sides woods.
Here are some physical facts about the two woods: The density of Brazilian is
somewhat higher (average specific gravity: .81) than Indian (average s.g.:
72). Brazilian is much more prone to cracking and dimensional instability than
Indian. On the other hand, Brazilian has an aesthetic loveliness unmatched by any
other wood I know of, although this varies tremendously from one set to another.
Does all this sound like an answer that's not an answer? That's why I no longer
recommend one of these woods or the other to my customers. |
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