My July and September columns
focused on strings, how they
drive the soundboard (head),
and how they affect the banjo’s tone and
amplitude. In my September column,
I showed a photo of several prototype
bridges and mentioned that one bridge
was a two-piece system designed so each
string rested over a foot. The photo and
description prompted several emails, and
some BNL readers wanted to know what
this bridge sounded like and how the
strings crossed over the two bridge parts
without interfering with the other part of
the bridge. Other readers wanted to know
more about the tone of each of the bridges
in the picture. So, this month, I’d like to
deal with each of these topics.
Fig. 1 show some other views of the
two-piece prototype bridge. The bridge is
made so that the three-footed section and
the two-footed section can interconnect
with each other without touching. The
ebony saddle is recessed under the area
where the string from one bridge passes
over the other bridge. In this way, the
strings from one section of the bridge do not
interfere with the other section. This bridge
provides excellent string-to-string balance
and good sustain. The bridge structure is a
bit delicate, and since the three-footed (and
three-stringed) section is only secured by
the down pressure of three strings, it tends
to slide around a bit more than a traditional
bridge if the player isn’t careful.
Fig. 1: Short of having one bridge piece for each
string, a two-piece bridge enables the greatest
independent connection of each string to the
soundboard (head). For photography purposes,
the two bridge sections have been separated
further than they would be in actual use.
As I pointed out last month, one of
the problems with unusual bridge designs
is that the outcome is often so different
from a traditional bridge that the tone it
provides bears no resemblance to what we
are accustomed to. The sound from using
a conventional three-footed five-string
banjo bridge emanates from a structure
that has two strings over arches (indirect
path to the head) and three strings over
feet (direct path to the head). This results
in the sound of the second and fourth
strings having different tone, amplitude,
and sustain qualities from the first, third,
and fifth strings. However, the tone
from this imbalanced arrangement is
so “normal” to us that any alteration of
that sound is considered either wrong
or different.
Fig.
2 The construction of each of these bridges yields dramatically
different tone, amplitude, and sustain.
Regarding the amplitude, tonal
attributes, and sustain qualities of the
other bridges in the photo, I’d like to
go through them one by one:
Bridge #1: Maple with ebony cap,
light construction, straight-footed,
with wide arches. This bridge provides
poor string-to-string balance, with
greater sustain on strings one, three, and
five. Likewise, the amplitude is noticeably
greater on strings one, three, and five than
on two and four.
Bridge #2: Maple with ebony cap,
medium construction, five straight-cut feet
(string over each foot). The five-footed
bridge provides excellent string-to-string
balance with good amplitude and sustain.
The tone is bright and snappy.
Bridge #3: Maple with ebony cap,
medium construction, five arch-cut feet
(string over each foot). The five-footed
bridge with arch cut-opens is quite similar
to Bridge #2. It provides excellent string-to-
string balance with good amplitude and
sustain. Like #2, the tone is bright and
snappy, but the size and stiffness of this
bridge provides a bit more punch than #2.
Bridge #4: Maple with ebony cap,
heavy construction, solid structure. The
solid bridge provides excellent string-to-
string balance but lacks in tonal color
(timbre). The sustain is good, but the
tone is muted and unclear. (This is not a
contradiction to “excellent string-to-string
balance.” The “balance” is excellent; the
timbre is not.) Could be an interesting
bridge for a clawhammer player.
Bridge #5: Maple with ebony cap,
medium construction, six straight-cut
feet (string over each arch). As with the
five-footed bridge, the six-footed bridge
provides excellent string-to-string balance
with good amplitude and sustain. However,
because the strings sit over arches, the tone
of this bridge is considerably warmer and
richer than the bridge with a string over
each foot (#2 and #3).
Bridge #6: Acrylic plastic, heavy
construction, traditional three-footed shape
and dimensions. The acrylic plastic bridge
is an interesting experiment. The tone is
considerably more muted than that of a
traditional three-footed bridge and lacks...
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