My
Soundboards
My harps use several forms of soundboard.
Let's start with the Gwydion. This ancient Celtic
harp uses the most traditional style. It's a solid
piece of (usually) Koa which has been split and
joined, book-matched, to make a long, elegant
soundboard with great balance and bass response. Care
must be taken that this sort of soundboard not split
over time since the grain runs in the same direction
as the centerstrip. Over the years I've found a number
of subtle ways to ensure against this.
For the Rhiannons and Conservatorys, I faced a
different problem. The conventional tonally "best"
soundboard is a solid Spruce board like on a piano.
Unfortunately, unlike a piano, the strings are trying
to pull the harp's soundboard apart. Over time, this
style of soundboard can split (This may be unsightly
and looks bad on the showroom floor but may actually
improve the harp's sound). The usual solution for this
is to glue a thin layer of wood, usually of the same
material, in the opposite grain direction over the
face of the board. You can see this on every pedal
harp (if you look inside most old pedal harps, you'll
also see the cracks). These are called laminate tops.
Unfortunately, that layer of glue and cross-grained
veneer create an acoustic stiffness which deadens the
tone. It's something like putting your hand on a
drumskin–it keeps it from ringing.
I had steadfastly insisted using solid, non-laminated
soundboards until 2007 when I saw a new possibility. I
began developing what became the Compound
Soundboard™ with Kevin Cloud (Berkeley Box Works) in the Winter
of 2007. It builds on work done by non-harp makers
over the last decade and allows me to continue to use
superior tone woods in a new and exciting way. The
wood is free to vibrate while being greatly
strengthened from underneath. Fortunately for me, how
the Compound Soundboard is made is invisible from the
outside, and I'm not going to tell you how I do it.
But you can definitely hear it!
The Compound Soundboard is now standard on
the Rhiannon. The first Rhiannon
to use it was debuted at the Big Sky Harp Conference
last sumer. Unfortunately (and against Kevin's
suggestions) I combined it with the Dynamic Tension
Balancing. The result was a drastically overbuilt
harp. The strings didn't properly couple to the
soundboard and the resulting tone was weak. But
listening closely, I could tell what was going on. It
was amazing. Even after being strung for only four
days, the highs had an open clarity I hadn't heard
before, and the bass had a new richness.
I've also developed a less labor intense variation of the
Compound Soundboard which I use on the Conservatory in tandem
with the Dynamic Tension Balancing.
On the Butterflys and SweetHarps I use a
high-grade plywood that I do secret, arcane things to
to make it speak more freely. Now, it may sound a bit
"cheap" to use plywood for a soundboard, even on an
inexpensive harp. But that's one of the benefits of
the Dynamic Tension Balancing. I can thin out the
soundboard without the risk of the harp exploding,
thereby getting much more response out of an otherwise
limited material.
