Making bridges

[Delwin D Fandrich]

----- Original Message -----
From: "Ron Nossaman" <RNossaman@cox.net>
To: <davidlovepianos@earthlink.net>; "Pianotech" <pianotech@ptg.org>
Sent: May 08, 2003 4:38 AM
Subject: Re: Making bridges


>
> It's true, that is part of the traditional argument. In practice, I'd be
> truly amazed if anyone by any measuring means could tell the difference
in
> performance. I always figured the alternating species laminations were to
> make the veneer stack easier to bend, but that didn't seem a sexy enough
> reason. I don't know for sure.
>
> Ron N


No, the folks who came up with the idea of using alternating species of
wood for the various layers did so because they believed the practice
somehow enhanced the "sound" of the bridges--it was believed that different
woods would produce different sounds. There has, of course, never been any
proof that this is the case but traditions die hard. In fact, in this
business it seems they don't die at all.

The use of varying species of wood in a bridge will affect its acoustical
performance only as it affects the mass and/or stiffness of the bridge and
soundboard assembly. The same is true of the grain orientation of the
layers used. For example, I would expect a piano using a maple bridge body
to have better sustain characteristics than one using a spruce bridge body.
I would also expect sustain to drop off between the ribs if the wood in the
bridge body were oriented vertically (perpendicular to the soundboard).

Del