Grain Direction in Maple Bridges
About grain direction in mandolin bridges:
Quarter-sawn wood, that is, with the grain lines parallel to
the top, just seems to sound the best. I have tried slab-cut wood on a lot of bridges and even
cross-cut wood on a few, but whenever I could make a comparison of different cuts of the same kind
of wood, the quarter-sawn wood always sounded better to me.
In making these bridges, I tried slab-cut wood first, because it was all I could cut from the small pieces
I had. The slab-cut bridges had a lot of volume and good clarity and sustain, but it turned out
later that they were generally lacking in low end and richness, compared to my later bridges.
I've tried cross-cut maple as well (if that's the right name for it)-- wood that was cut crosswise to the grain.
This was strange wood to work. It felt very soft sometimes, almost spongy compared to the other cuts,
and the bridges made this way did not have much vertical rigidity, but compressed a lot under string pressure.
The tone of these bridges was very "thunky," you might say, with pretty good lows,
but the sound as a whole suffered and the volume was not especially good.
I first tried quarter-sawn maple only after I acquired some pieces of wood that were big enough (in the right direction)
to cut that way. It was about with bridges #27-28 that I really settled on the quarter-sawn wood as the best
to use. By then I had done a lot of experiments, and it was fairly obvious that maple that was sawn on
the quarter simply delivered more consistent
richness in the sound than I could achieve with the other cuts. (This also seems to be true with other promising bridge
woods, such as mahogany and close-grained cherry-- they sound better when cut on the quarter.)
I suspect that quarter-sawn wood sounds better because the wood is springier in that direction, as
opposed to the rigidity of slab-cut wood. However, the exact cut does not seem to be critical,
because bridge wood that is within 30 or 35 degrees of being quarter-sawn shows no difference in
sound (as far as I can hear) compared to very closely-quartered wood, as you find in a good violin bridge. And
speaking of violin bridges, they are all quarter-sawn, and banjo bridges usually are too, so my experiments with
various cuts of wood may have been just re-inventing the wheel!
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