Sound waves(The behavior of soundboards)

[Cy Shuster]

I'd agree with your summary, Roy: a firmer attachment, keeping more energy
in the strings.

It says here (http://www.wapin.com/overview.htm) that "more energy is
reflected back to the string, creating less of a dampening effect than the
traditional arrangement"... "The traditional way of installing angled bridge
pins at the first termination point...appears to provide a stronger than
necessary coupling.  This strong coupling takes large bits of the mechanical
energy in the string, before it even has a chance to convert itself to
harmonic energy (first 30-60 milliseconds), and dispenses it as attach
noise.  The Wapin technology, in contrast, de-couples slightly the energy
between the bridge and the soundboard...".

I'd type more of the liner notes, but they're copyrighted.  A key point is
"a vibrating string in a piano takes on a substantial movement in the
unstruck direction shortly after it receives the blow from the piano
hammer."

Apparently this bridge was covered in the Piano Technicians Journal, Jan.
1999, pp. 31-34.

The (very large) link to the patent is:

http://164.195.100.11/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=/neta
html/search-bool.html&r=1&f=G&l=50&co1=AND&d=ft00&s1=wapin&OS=wapin&RS=wapin

--Cy Shuster--
Rochester, MN

----- Original Message -----
From: "Roy Peters" <roy.peters@mindspring.com>
To: <pianotech@ptg.org>
Sent: January 24, 2002 12:02 AM
Subject: Re: Sound waves(The behavior of soundboards)


> Does it really say that the system acts as a resistor?  As I understand
Wapin,
> the idea is that less energy bleeds off as attack noise.  A slanted pin
dampens
> the string.  Moving the front pin to a vertical position lets the string
ring
> more freely.   I will have to read the liner notes again, but I think that
this
> is what was meant.
>
> Roy Peters
> Cincinnati, Ohio
>