BACK vs. ROUND BACK
the difference? Which is better?
Double Basses were most likely built by artisans experienced
in the making of Viols, and by others experienced in the making
of Violins. The Viol family of instruments were built with
flat backs; the Violin family with round, or carved backs.
There is some disagreement amongst musical historians about
the actual lineage of the double bass. Unlike most other stringed
instruments, the bass has never become truly standardized
in its 400-plus-year history. There are abundant flat-backed,
round-backed, violin-cornered, gamba-cornered, busetto-cornered,
corner-less, high-shouldered, sloped-shouldered, wide-ribbed,
narrow-ribbed, chunky and svelte basses around to this day.
Basses usually have a break or bend in the midst of the back
in the upper bout, tapering into the neck block, which allows
the instrument to nestle closer to the player. This feature
is unique within the violin family.
Flat-backed basses are more economical to make, for two reasons:
1) The back requires about 1/4 the thickness of rough-cut
wood, and: 2) A lot of labor is saved in the making because
the back is not carved out. (Some makers prefer to build flat
backs because it conserves a dwindling resource; fine tonewood.
Nowadays, lots of beautiful tonewood is being wasted on the
building of mediocre (and worse) instruments, putting pressure
on a tight, shrinking supply.) So, if a flat-backed bass requires
less wood and less labor to build, should it be priced lower
than a round-backed one? The answer is yes, and no. A bass
maker who does the work by hand should be able to pass along
some savings (in the case of a flat- backed bass) to the buyer.
A commercial shop that primarily machines its work probably
considers the difference a wash, as they'll need to make and
install bracing in a flat back, while they would need more
material for the carved round back. In the case of older basses
it's mostly a non-issue, as they are marketed and priced mainly
based on their tone, playability and area of origin (and sometimes
based on the particular maker).
is some argument in the bass community over which type of
back sounds "better." Some players and makers believe
that flat-backed basses sound "punchier" and have
a more immediate response. They also tend to feel that round-backed
basses sound deeper, darker and perhaps project more, because
of their larger interior air volume. And I'm pretty sure there
are folks who believe the opposite of both of these statements.
I'm personally of the opinion that in a darkened room, most
listeners could not tell a flat-backed bass from a round-backed
one. It would be nearly impossible, however, to prove any
of this, unless one had access to two identical basses, both
made from the same wood, at the same time, with the same exact
measurements, weights, thicknesses of parts, varnish, etc,
set-up in an identical manner, but with a flat back on one
and a round back on the other. (Stay tuned, as a colleague
of mine has recently built a pair of basses exactly as I've
just described. I'm anxious to hear about the results, and
will pass on what I learn, pending his permission).
for a moment the statement I just made about the darkened
room. There is, in my opinion, a difference in the way flat-backed
and round-backed basses respond to bow or pizzicato input.
I hold that this is not really because of the contour of the
back, but because of the bracing which is attached to a flat
back. Because round backs are thicker and arched, they generally
do not need to be beefed up in the area of the soundpost.
Flat backs, on the other hand, are made of thin wood, usually
4 to 6 millimeters or so, and require braces to help them
keep their shape under the pressure of the soundpost and the
torsion of the strings. The braces, traditionally glued-on
across the back, are made of spruce, or a similar softwood.
Spruce is extremely stiff and springy, and when pushed in
one direction, it springs back quickly in the other direction.
This imparts a certain feedback to the player which can be
perceived as quickness under the bow, or punchiness when plucked.
Think of the spruce brace as a spring; the bridge rocks from
string input, propelling the soundpost down into the brace,
which springs back upward, amplifying the input. This is a
gross oversimplification of the modality that actually happens
when a bass is played, but I think it serves to clarify my
idea. Some players describe this effect as a "strong
front of the note." A recording engineer would call it
controversy among makers concerns whether the back of a bass
should be heavy and solid, and resist vibrating, or be light
and resilient, and vibrate freely. Those in the first camp
assert that a stiff, unyielding back allows more of the energy
to be focused on the top table, where it will better project
to the listener. Those in the second camp assert that a bass
back is like a secondary sound board, and should be allowed
to vibrate freely, and since bass frequencies are mostly omnidirectional,
it makes no difference where the sound is emanating from.
I have worked on basses with heavy, stiff backs, and also
on those with lighter, more vibrational ones. Both can sound
good, but I personally prefer the tone and response of a bass
that is built on the lighter side. It is also worth noting
that most every bass player can tell the difference between
the way his bass sounds and responds when standing (without
leaning into the back), and when sitting, with one's leg and
knee damping the back of the instrument. This damping seems
to affect flat-backed basses more than their round-backed
cousins. If you have ever played classical guitar, or closely
observed one being played, you will know that it is important
for the back of the guitar to be free of the player's body,
so that the full resonance of the instrument can be heard.
Ideally, a bass should be played in the same manner, though
sitting on a stool during a long orchestral or operatic performance
is just about a necessity. (Wagner be damned.)
Part 2 of this article, I will discuss the pros and cons of
the flat back vs. the round back from the standpoint of the
health and longevity of the bass. Kindly refer any questions
you may have to ArnoldS@aesbass.com.
I look forward to answering them in future issues.
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